XmlSerializer Construtores

protected:
 XmlSerializer();

protected XmlSerializer ();

Protected Sub New ()

public:
 XmlSerializer(Type ^ type);

public XmlSerializer (Type type);

new System.Xml.Serialization.XmlSerializer : Type -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type)

Parâmetros

Exemplos

O exemplo a seguir constrói um XmlSerializer que serializa um objeto chamado Widget. O exemplo define várias propriedades do objeto antes de chamar o Serialize método.

private:
   void SerializeObject( String^ filename )
   {
      XmlSerializer^ serializer =
         gcnew XmlSerializer( OrderedItem::typeid );

      // Create an instance of the class to be serialized.
      OrderedItem^ i = gcnew OrderedItem;

      // Set the public property values.
      i->ItemName = "Widget";
      i->Description = "Regular Widget";
      i->Quantity = 10;
      i->UnitPrice = (Decimal)2.30;

      // Writing the document requires a TextWriter.
      TextWriter^ writer = gcnew StreamWriter( filename );

      // Serialize the object, and close the TextWriter.
      serializer->Serialize( writer, i );
      writer->Close();
   }

public:
   // This is the class that will be serialized.
   ref class OrderedItem
   {
   public:
      String^ ItemName;
      String^ Description;
      Decimal UnitPrice;
      int Quantity;
   };

private void SerializeObject(string filename)
{
   XmlSerializer serializer =
   new XmlSerializer(typeof(OrderedItem));

   // Create an instance of the class to be serialized.
   OrderedItem i = new OrderedItem();

   // Set the public property values.
   i.ItemName = "Widget";
   i.Description = "Regular Widget";
   i.Quantity = 10;
   i.UnitPrice = (decimal) 2.30;

   // Writing the document requires a TextWriter.
   TextWriter writer = new StreamWriter(filename);

   // Serialize the object, and close the TextWriter.
   serializer.Serialize(writer, i);
   writer.Close();
}

// This is the class that will be serialized.
public class OrderedItem
{
   public string ItemName;
   public string Description;
   public decimal UnitPrice;
   public int Quantity;
}

Private Sub SerializeObject(ByVal filename As String)
    Dim serializer As New XmlSerializer(GetType(OrderedItem))
    
    ' Create an instance of the class to be serialized.
    Dim i As New OrderedItem()
    
    ' Set the public property values.
    With i
        .ItemName = "Widget"
        .Description = "Regular Widget"
        .Quantity = 10
        .UnitPrice = CDec(2.3)
    End With
    
    ' Writing the document requires a TextWriter.
    Dim writer As New StreamWriter(filename)
    
    ' Serialize the object, and close the TextWriter.
    serializer.Serialize(writer, i)
    writer.Close()
End Sub


' This is the class that will be serialized.
Public Class OrderedItem
    Public ItemName As String
    Public Description As String
    Public UnitPrice As Decimal
    Public Quantity As Integer
End Class

Comentários

Normalmente, um aplicativo define várias classes que o XmlSerializer converte em um único documento de instância XML. No entanto, o XmlSerializer deve saber apenas um tipo: o tipo da classe que representa o elemento raiz XML. O XmlSerializer serializa automaticamente todas as instâncias de classe subordinadas. Da mesma forma, somente o tipo do elemento raiz XML é necessário para desserialização.

Confira também

• Serialize(TextWriter, Object)
• Deserialize(Stream)
• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(System::Xml::Serialization::XmlTypeMapping ^ xmlTypeMapping);

public XmlSerializer (System.Xml.Serialization.XmlTypeMapping xmlTypeMapping);

new System.Xml.Serialization.XmlSerializer : System.Xml.Serialization.XmlTypeMapping -> System.Xml.Serialization.XmlSerializer

Public Sub New (xmlTypeMapping As XmlTypeMapping)

Parâmetros

Exemplos

O exemplo a seguir serializa uma classe chamada Group. A serialização dos GroupNamecampos e IgnoreThis os membros da GroupType enumeração são substituídos. CreateOverrideSerializer No método, um SoapAttributeOverrides objeto é criado e, para cada membro substituído ou enumeração, um SoapAttributes objeto é criado com o conjunto de propriedades apropriado e adicionado ao SoapAttributeOverrides objeto. Um XmlMapping objeto é criado usando o SoapAttributeOverrides objeto e esse XmlMapping objeto é usado para criar o XmlSerializer que substitui a serialização padrão.

#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Text;
using namespace System::Xml;
using namespace System::Xml::Serialization;
using namespace System::Xml::Schema;
ref class Car;

// SoapInclude allows Vehicle to accept Car type.

[SoapInclude(Car::typeid)]
public ref class Vehicle abstract
{
public:
   String^ licenseNumber;
   DateTime makeDate;
};

public ref class Car: public Vehicle{};

public enum class GroupType
{
   // These enums can be overridden.
   [SoapEnum("Small")]
   A,
   [SoapEnum("Large")]
   B
};

public ref class Group
{
public:

   [SoapAttributeAttribute(Namespace="http://www.cpandl.com")]
   String^ GroupName;

   [SoapAttributeAttribute(DataType="base64Binary")]
   array<Byte>^GroupNumber;

   [SoapAttributeAttribute(DataType="date",AttributeName="CreationDate")]
   DateTime Today;

   [SoapElement(DataType="nonNegativeInteger",ElementName="PosInt")]
   String^ PostitiveInt;

   // This is ignored when serialized unless it's overridden.

   [SoapIgnore]
   bool IgnoreThis;
   GroupType Grouptype;
   Vehicle^ MyVehicle;

   // The SoapInclude allows the method to return a Car.

   [SoapInclude(Car::typeid)]
   Vehicle^ myCar( String^ licNumber )
   {
      Vehicle^ v;
      if ( licNumber->Equals( "" ) )
      {
         v = gcnew Car;
         v->licenseNumber = "!!!!!!";
      }
      else
      {
         v = gcnew Car;
         v->licenseNumber = licNumber;
      }

      return v;
   }
};

public ref class Run
{
public:
   static void main()
   {
      Run^ test = gcnew Run;
      test->SerializeOriginal( "SoapOriginal.xml" );
      test->SerializeOverride( "SoapOverrides.xml" );
      test->DeserializeOriginal( "SoapOriginal.xml" );
      test->DeserializeOverride( "SoapOverrides.xml" );
   }

   void SerializeOriginal( String^ filename )
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping^ myMapping = (gcnew SoapReflectionImporter)->ImportTypeMapping( Group::typeid );
      XmlSerializer^ mySerializer = gcnew XmlSerializer( myMapping );
      Group^ myGroup = MakeGroup();

      // Writing the file requires a TextWriter.
      XmlTextWriter^ writer = gcnew XmlTextWriter( filename,Encoding::UTF8 );
      writer->Formatting = Formatting::Indented;
      writer->WriteStartElement( "wrapper" );

      // Serialize the class, and close the TextWriter.
      mySerializer->Serialize( writer, myGroup );
      writer->WriteEndElement();
      writer->Close();
   }

   void SerializeOverride( String^ filename )
   {
      // Create an instance of the XmlSerializer class
      // that overrides the serialization.
      XmlSerializer^ overRideSerializer = CreateOverrideSerializer();
      Group^ myGroup = MakeGroup();

      // Writing the file requires a TextWriter.
      XmlTextWriter^ writer = gcnew XmlTextWriter( filename,Encoding::UTF8 );
      writer->Formatting = Formatting::Indented;
      writer->WriteStartElement( "wrapper" );

      // Serialize the class, and close the TextWriter.
      overRideSerializer->Serialize( writer, myGroup );
      writer->WriteEndElement();
      writer->Close();
   }

private:
   Group^ MakeGroup()
   {
      // Create an instance of the class that will be serialized.
      Group^ myGroup = gcnew Group;

      // Set the object properties.
      myGroup->GroupName = ".NET";
      array<Byte>^hexByte = {Convert::ToByte( 100 ),Convert::ToByte( 50 )};
      myGroup->GroupNumber = hexByte;
      DateTime myDate = DateTime(2002,5,2);
      myGroup->Today = myDate;
      myGroup->PostitiveInt = "10000";
      myGroup->IgnoreThis = true;
      myGroup->Grouptype = GroupType::B;
      Car^ thisCar = dynamic_cast<Car^>(myGroup->myCar( "1234566" ));
      myGroup->MyVehicle = thisCar;
      return myGroup;
   }

public:
   void DeserializeOriginal( String^ filename )
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping^ myMapping = (gcnew SoapReflectionImporter)->ImportTypeMapping( Group::typeid );
      XmlSerializer^ mySerializer = gcnew XmlSerializer( myMapping );

      // Reading the file requires an  XmlTextReader.
      XmlTextReader^ reader = gcnew XmlTextReader( filename );
      reader->ReadStartElement( "wrapper" );

      // Deserialize and cast the object.
      Group^ myGroup;
      myGroup = dynamic_cast<Group^>(mySerializer->Deserialize( reader ));
      reader->ReadEndElement();
      reader->Close();
   }

   void DeserializeOverride( String^ filename )
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer^ overRideSerializer = CreateOverrideSerializer();

      // Reading the file requires an XmlTextReader.
      XmlTextReader^ reader = gcnew XmlTextReader( filename );
      reader->ReadStartElement( "wrapper" );

      // Deserialize and cast the object.
      Group^ myGroup;
      myGroup = dynamic_cast<Group^>(overRideSerializer->Deserialize( reader ));
      reader->ReadEndElement();
      reader->Close();
      ReadGroup( myGroup );
   }

private:
   void ReadGroup( Group^ myGroup )
   {
      Console::WriteLine( myGroup->GroupName );
      Console::WriteLine( myGroup->GroupNumber[ 0 ] );
      Console::WriteLine( myGroup->GroupNumber[ 1 ] );
      Console::WriteLine( myGroup->Today );
      Console::WriteLine( myGroup->PostitiveInt );
      Console::WriteLine( myGroup->IgnoreThis );
      Console::WriteLine();
   }

   XmlSerializer^ CreateOverrideSerializer()
   {
      SoapAttributeOverrides^ mySoapAttributeOverrides = gcnew SoapAttributeOverrides;
      SoapAttributes^ soapAtts = gcnew SoapAttributes;
      SoapElementAttribute^ mySoapElement = gcnew SoapElementAttribute;
      mySoapElement->ElementName = "xxxx";
      soapAtts->SoapElement = mySoapElement;
      mySoapAttributeOverrides->Add( Group::typeid, "PostitiveInt", soapAtts );

      // Override the IgnoreThis property.
      SoapIgnoreAttribute^ myIgnore = gcnew SoapIgnoreAttribute;
      soapAtts = gcnew SoapAttributes;
      soapAtts->SoapIgnore = false;
      mySoapAttributeOverrides->Add( Group::typeid, "IgnoreThis", soapAtts );

      // Override the GroupType enumeration. 
      soapAtts = gcnew SoapAttributes;
      SoapEnumAttribute^ xSoapEnum = gcnew SoapEnumAttribute;
      xSoapEnum->Name = "Over1000";
      soapAtts->GroupType::SoapEnum = xSoapEnum;

      // Add the SoapAttributes to the 
      // mySoapAttributeOverridesrides object.
      mySoapAttributeOverrides->Add( GroupType::typeid, "A", soapAtts );

      // Create second enumeration and add it.
      soapAtts = gcnew SoapAttributes;
      xSoapEnum = gcnew SoapEnumAttribute;
      xSoapEnum->Name = "ZeroTo1000";
      soapAtts->GroupType::SoapEnum = xSoapEnum;
      mySoapAttributeOverrides->Add( GroupType::typeid, "B", soapAtts );

      // Override the Group type.
      soapAtts = gcnew SoapAttributes;
      SoapTypeAttribute^ soapType = gcnew SoapTypeAttribute;
      soapType->TypeName = "Team";
      soapAtts->SoapType = soapType;
      mySoapAttributeOverrides->Add( Group::typeid, soapAtts );

      // Create an XmlTypeMapping that is used to create an instance 
      // of the XmlSerializer. Then return the XmlSerializer object.
      XmlTypeMapping^ myMapping = (gcnew SoapReflectionImporter( mySoapAttributeOverrides ))->ImportTypeMapping( Group::typeid );
      XmlSerializer^ ser = gcnew XmlSerializer( myMapping );
      return ser;
   }
};

int main()
{
   Run::main();
}

using System;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using System.Xml.Schema;

public class Group
{
   [SoapAttribute (Namespace = "http://www.cpandl.com")]
   public string GroupName;

   [SoapAttribute(DataType = "base64Binary")]
   public Byte [] GroupNumber;

   [SoapAttribute(DataType = "date", AttributeName = "CreationDate")]
   public DateTime Today;
   [SoapElement(DataType = "nonNegativeInteger", ElementName = "PosInt")]
   public string PostitiveInt;
   // This is ignored when serialized unless it's overridden.
   [SoapIgnore]
   public bool IgnoreThis;

   public GroupType Grouptype;

   public Vehicle MyVehicle;

   // The SoapInclude allows the method to return a Car.
   [SoapInclude(typeof(Car))]
   public Vehicle myCar(string licNumber)
   {
      Vehicle v;
      if(licNumber == "")
         {
            v = new Car();
        v.licenseNumber = "!!!!!!";
     }
      else
     {
       v = new Car();
       v.licenseNumber = licNumber;
     }
      return v;
   }
}

// SoapInclude allows Vehicle to accept Car type.
[SoapInclude(typeof(Car))]
public abstract class Vehicle
{
   public string licenseNumber;
   public DateTime makeDate;
}

public class Car: Vehicle
{
}

public enum GroupType
{
   // These enums can be overridden.
   [SoapEnum("Small")]
   A,
   [SoapEnum("Large")]
   B
}

public class Run
{
   public static void Main()
   {
      Run test = new Run();
      test.SerializeOriginal("SoapOriginal.xml");
      test.SerializeOverride("SoapOverrides.xml");
      test.DeserializeOriginal("SoapOriginal.xml");
      test.DeserializeOverride("SoapOverrides.xml");
   }
   public void SerializeOriginal(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping myMapping =
      (new SoapReflectionImporter().ImportTypeMapping(
      typeof(Group)));
      XmlSerializer mySerializer =
      new XmlSerializer(myMapping);
      Group myGroup=MakeGroup();
      // Writing the file requires a TextWriter.
      XmlTextWriter writer =
      new XmlTextWriter(filename, Encoding.UTF8);
      writer.Formatting = Formatting.Indented;
      writer.WriteStartElement("wrapper");
      // Serialize the class, and close the TextWriter.
      mySerializer.Serialize(writer, myGroup);
      writer.WriteEndElement();
      writer.Close();
   }

   public void SerializeOverride(string filename)
   {
      // Create an instance of the XmlSerializer class
      // that overrides the serialization.
      XmlSerializer overRideSerializer = CreateOverrideSerializer();
      Group myGroup=MakeGroup();
      // Writing the file requires a TextWriter.
      XmlTextWriter writer =
      new XmlTextWriter(filename, Encoding.UTF8);
      writer.Formatting = Formatting.Indented;
      writer.WriteStartElement("wrapper");
      // Serialize the class, and close the TextWriter.
      overRideSerializer.Serialize(writer, myGroup);
      writer.WriteEndElement();
      writer.Close();
   }

   private Group MakeGroup(){
      // Create an instance of the class that will be serialized.
      Group myGroup = new Group();

      // Set the object properties.
      myGroup.GroupName = ".NET";

      Byte [] hexByte = new Byte[2]{Convert.ToByte(100),
      Convert.ToByte(50)};
      myGroup.GroupNumber = hexByte;

      DateTime myDate = new DateTime(2002,5,2);
      myGroup.Today = myDate;
      myGroup.PostitiveInt= "10000";
      myGroup.IgnoreThis=true;
      myGroup.Grouptype= GroupType.B;
      Car thisCar =(Car)  myGroup.myCar("1234566");
      myGroup.MyVehicle=thisCar;
      return myGroup;
   }   	

   public void DeserializeOriginal(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping myMapping =
      (new SoapReflectionImporter().ImportTypeMapping(
      typeof(Group)));
      XmlSerializer mySerializer =
      new XmlSerializer(myMapping);

      // Reading the file requires an  XmlTextReader.
      XmlTextReader reader=
      new XmlTextReader(filename);
      reader.ReadStartElement("wrapper");

      // Deserialize and cast the object.
      Group myGroup;
      myGroup = (Group) mySerializer.Deserialize(reader);
      reader.ReadEndElement();
      reader.Close();
   }

   public void DeserializeOverride(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlSerializer overRideSerializer = CreateOverrideSerializer();

      // Reading the file requires an  XmlTextReader.
      XmlTextReader reader=
      new XmlTextReader(filename);
      reader.ReadStartElement("wrapper");

      // Deserialize and cast the object.
      Group myGroup;
      myGroup = (Group) overRideSerializer.Deserialize(reader);
      reader.ReadEndElement();
      reader.Close();
      ReadGroup(myGroup);
   }

   private void ReadGroup(Group myGroup){
      Console.WriteLine(myGroup.GroupName);
      Console.WriteLine(myGroup.GroupNumber[0]);
      Console.WriteLine(myGroup.GroupNumber[1]);
      Console.WriteLine(myGroup.Today);
      Console.WriteLine(myGroup.PostitiveInt);
      Console.WriteLine(myGroup.IgnoreThis);
      Console.WriteLine();
   }
   private XmlSerializer CreateOverrideSerializer()
   {
      SoapAttributeOverrides mySoapAttributeOverrides =
      new SoapAttributeOverrides();
      SoapAttributes soapAtts = new SoapAttributes();

      SoapElementAttribute mySoapElement = new SoapElementAttribute();
      mySoapElement.ElementName = "xxxx";
      soapAtts.SoapElement = mySoapElement;
      mySoapAttributeOverrides.Add(typeof(Group), "PostitiveInt",
      soapAtts);

      // Override the IgnoreThis property.
      SoapIgnoreAttribute myIgnore = new SoapIgnoreAttribute();
      soapAtts = new SoapAttributes();
      soapAtts.SoapIgnore = false;
      mySoapAttributeOverrides.Add(typeof(Group), "IgnoreThis",
      soapAtts);

      // Override the GroupType enumeration.	
      soapAtts = new SoapAttributes();
      SoapEnumAttribute xSoapEnum = new SoapEnumAttribute();
      xSoapEnum.Name = "Over1000";
      soapAtts.SoapEnum = xSoapEnum;

      // Add the SoapAttributes to the
      // mySoapAttributeOverridesrides object.
      mySoapAttributeOverrides.Add(typeof(GroupType), "A",
      soapAtts);

      // Create second enumeration and add it.
      soapAtts = new SoapAttributes();
      xSoapEnum = new SoapEnumAttribute();
      xSoapEnum.Name = "ZeroTo1000";
      soapAtts.SoapEnum = xSoapEnum;
      mySoapAttributeOverrides.Add(typeof(GroupType), "B",
      soapAtts);

      // Override the Group type.
      soapAtts = new SoapAttributes();
      SoapTypeAttribute soapType = new SoapTypeAttribute();
      soapType.TypeName = "Team";
      soapAtts.SoapType = soapType;
      mySoapAttributeOverrides.Add(typeof(Group),soapAtts);

      // Create an XmlTypeMapping that is used to create an instance
      // of the XmlSerializer. Then return the XmlSerializer object.
      XmlTypeMapping myMapping = (new SoapReflectionImporter(
      mySoapAttributeOverrides)).ImportTypeMapping(typeof(Group));
    
      XmlSerializer ser = new XmlSerializer(myMapping);
      return ser;
   }
}

Imports System.IO
Imports System.Text
Imports System.Xml
Imports System.Xml.Serialization
Imports System.Xml.Schema

Public Class Group
   <SoapAttribute (Namespace:= "http:'www.cpandl.com")> _
   Public GroupName As String 
   
   <SoapAttribute(DataType:= "base64Binary")> _
   Public GroupNumber() As Byte

   <SoapAttribute(DataType:= "date", _
   AttributeName:= "CreationDate")> _
   Public Today As DateTime 
   <SoapElement(DataType:= "nonNegativeInteger", _
   ElementName:= "PosInt")> _
   Public PostitiveInt As String 
   ' This is ignored when serialized unless it's overridden.
   <SoapIgnore> _ 
   Public IgnoreThis As Boolean 
   
   Public Grouptype As GroupType 

   Public MyVehicle As Vehicle 

   '  The SoapInclude allows the method to return a Car.
   <SoapInclude(GetType(Car))> _
   Public Function myCar(licNumber As String ) As Vehicle 
      Dim v As Vehicle 
      if licNumber = "" Then
         v = New Car()
         v.licenseNumber = "!!!!!!"
      else  
       v = New Car()
       v.licenseNumber = licNumber
      End If
      
      return v
   End Function
End Class
  
' SoapInclude allows Vehicle to accept Car type.
<SoapInclude(GetType(Car))> _
Public MustInherit  class Vehicle
   Public licenseNumber As String 
   Public makeDate As DateTime 
End Class

Public Class Car
   Inherits Vehicle

End Class

Public enum GroupType
   ' These enums can be overridden.
   <SoapEnum("Small")> _
   A
   <SoapEnum("Large")> _ 
   B
End Enum
 
Public Class Run

   Shared Sub Main()
      Dim test As Run = New Run()
      test.SerializeOriginal("SoapOriginal.xml")
      test.SerializeOverride("SoapOverrides.xml")
      test.DeserializeOriginal("SoapOriginal.xml")
      test.DeserializeOverride("SoapOverrides.xml")
   End SUb
   
   Public Sub SerializeOriginal(filename As String)

      ' Create an instance of the XmlSerializer class.
      Dim myMapping As XmlTypeMapping = _
      (New SoapReflectionImporter().ImportTypeMapping _
      (GetType(Group)))
      Dim mySerializer As XmlSerializer =  _
      New XmlSerializer(myMapping)
      
      Dim myGroup As Group =MakeGroup()
      ' Writing the file requires a TextWriter.
      Dim writer As XmlTextWriter  = _
      New XmlTextWriter(filename, Encoding.UTF8)
      writer.Formatting = Formatting.Indented
      writer.WriteStartElement("wrapper")
      ' Serialize the class, and close the TextWriter.
      mySerializer.Serialize(writer, myGroup)
      writer.WriteEndElement()
      writer.Close()
   End Sub

   Public Sub SerializeOverride(filename As String)
      ' Create an instance of the XmlSerializer class
      ' that overrides the serialization.
      Dim overRideSerializer As XmlSerializer = _
      CreateOverrideSerializer()
      Dim myGroup As Group =MakeGroup()
      ' Writing the file requires a TextWriter.
      Dim writer As XmlTextWriter  = _
      New XmlTextWriter(filename, Encoding.UTF8)
      writer.Formatting = Formatting.Indented
      writer.WriteStartElement("wrapper")
      ' Serialize the class, and close the TextWriter.
      overRideSerializer.Serialize(writer, myGroup)
      writer.WriteEndElement()
      writer.Close()
    End Sub

   private Function MakeGroup() As Group 
      ' Create an instance of the class that will be serialized.
      Dim myGroup As Group  = New Group()

      ' Set the object properties.
      myGroup.GroupName = ".NET"

      Dim hexByte()As Byte = new Byte(1){Convert.ToByte(100), _
      Convert.ToByte(50)}
      myGroup.GroupNumber = hexByte

      Dim myDate As DateTime  = new DateTime(2002,5,2)
      myGroup.Today = myDate

      myGroup.PostitiveInt = "10000"
    myGroup.IgnoreThis = true
    myGroup.Grouptype = GroupType.B
    Dim thisCar As Car 
    thisCar =CType(myGroup.myCar("1234566"), Car)
    myGroup.myVehicle=thisCar
      return myGroup
   End Function   	

   Public Sub DeserializeOriginal(filename As String)
      ' Create an instance of the XmlSerializer class.
      Dim myMapping As XmlTypeMapping = _
      (New SoapReflectionImporter().ImportTypeMapping _
      (GetType(Group)))
      Dim mySerializer As XmlSerializer =  _
      New XmlSerializer(myMapping)

      ' Reading the file requires an  XmlTextReader.
      Dim reader As XmlTextReader = _
      New XmlTextReader(filename)
      reader.ReadStartElement("wrapper")

      ' Deserialize and cast the object.
      Dim myGroup As Group  = _
      CType(mySerializer.Deserialize(reader), Group)
      reader.ReadEndElement()
      reader.Close()
   End Sub

   Public Sub DeserializeOverride(filename As String)
      ' Create an instance of the XmlSerializer class.
      Dim overRideSerializer As XmlSerializer  = _
      CreateOverrideSerializer()

      ' Reading the file requires an  XmlTextReader.
      Dim reader As XmlTextReader = _
      New XmlTextReader(filename)
      reader.ReadStartElement("wrapper")

      ' Deserialize and cast the object.
      Dim myGroup As Group = _
      CType(overRideSerializer.Deserialize(reader), Group)
      reader.ReadEndElement()
      reader.Close()
      ReadGroup(myGroup)
   End Sub

   private Sub ReadGroup(myGroup As Group)
      Console.WriteLine(myGroup.GroupName)
      Console.WriteLine(myGroup.GroupNumber(0))
      Console.WriteLine(myGroup.GroupNumber(1))
      Console.WriteLine(myGroup.Today)
      Console.WriteLine(myGroup.PostitiveInt)
      Console.WriteLine(myGroup.IgnoreThis)
      Console.WriteLine()
   End Sub
   
   Private Function CreateOverrideSerializer() As XmlSerializer
      Dim soapOver As SoapAttributeOverrides = New SoapAttributeOverrides()
      Dim soapAtts As SoapAttributes = New SoapAttributes()

      Dim mySoapElement As SoapElementAttribute = New SoapElementAttribute()
      mySoapElement.ElementName = "xxxx"
      soapAtts.SoapElement = mySoapElement
      soapOver.Add(GetType(Group), "PostitiveInt", soapAtts)

      ' Override the IgnoreThis property.
      Dim myIgnore As SoapIgnoreAttribute  = new SoapIgnoreAttribute()
      soapAtts = New SoapAttributes()
      soapAtts.SoapIgnore = false
      soapOver.Add(GetType(Group), "IgnoreThis", soapAtts)

      ' Override the GroupType enumeration.
      soapAtts = New SoapAttributes()
      Dim xSoapEnum As SoapEnumAttribute = new SoapEnumAttribute()
      xSoapEnum.Name = "Over1000"
      soapAtts.SoapEnum = xSoapEnum
      ' Add the SoapAttributes to the SoapOverrides object.
      soapOver.Add(GetType(GroupType), "A", soapAtts)

      ' Create second enumeration and add it.
      soapAtts = New SoapAttributes()
      xSoapEnum = New SoapEnumAttribute()
      xSoapEnum.Name = "ZeroTo1000"
      soapAtts.SoapEnum = xSoapEnum
      soapOver.Add(GetType(GroupType), "B", soapAtts)

      ' Override the Group type.
      soapAtts = New SoapAttributes()
      Dim soapType As SoapTypeAttribute = New SoapTypeAttribute()
      soapType.TypeName = "Team"
      soapAtts.SoapType = soapType
      soapOver.Add(GetType(Group),soapAtts)
    
      Dim myMapping As XmlTypeMapping = (New SoapReflectionImporter( _
      soapOver)).ImportTypeMapping(GetType(Group))
    
       Dim ser As XmlSerializer = new XmlSerializer(myMapping)
      return ser
   End Function
End Class

Comentários

Esse construtor é usado para criar um XmlSerializer quando você serializa um objeto em uma mensagem SOAP. Para controlar as mensagens SOAP geradas, use os atributos especiais (começando pela palavra "Soap") encontrados no System.Xml.Serialization namespace.

Confira também

• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(Type ^ type, System::String ^ defaultNamespace);

public XmlSerializer (Type type, string defaultNamespace);

public XmlSerializer (Type type, string? defaultNamespace);

new System.Xml.Serialization.XmlSerializer : Type * string -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, defaultNamespace As String)

Parâmetros

Exemplos

O exemplo a seguir constrói um XmlSerializer que serializa um objeto chamado Widget. O exemplo define várias propriedades do objeto antes de chamar o Serialize método.

private:
   void SerializeObject( String^ filename )
   {
      XmlSerializer^ serializer = gcnew XmlSerializer(
         OrderedItem::typeid,"http://www.cpandl.com" );

      // Create an instance of the class to be serialized.
      OrderedItem^ i = gcnew OrderedItem;

      // Insert code to set property values.

      // Writing the document requires a TextWriter.
      TextWriter^ writer = gcnew StreamWriter( filename );
      // Serialize the object, and close the TextWriter
      serializer->Serialize( writer, i );
      writer->Close();
   }

   void DeserializeObject( String^ filename )
   {
      XmlSerializer^ serializer = gcnew XmlSerializer(
         OrderedItem::typeid,"http://www.cpandl.com" );
      // A FileStream is needed to read the XML document.
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );

      // Declare an object variable of the type to be deserialized.
      OrderedItem^ i;

      // Deserialize the object.
      i = dynamic_cast<OrderedItem^>(serializer->Deserialize( fs ));

      // Insert code to use the properties and methods of the object.
   }

private void SerializeObject(string filename) {
    XmlSerializer serializer = new XmlSerializer
        (typeof(OrderedItem), "http://www.cpandl.com");

    // Create an instance of the class to be serialized.
    OrderedItem i = new OrderedItem();

    // Insert code to set property values.

    // Writing the document requires a TextWriter.
    TextWriter writer = new StreamWriter(filename);
    // Serialize the object, and close the TextWriter
    serializer.Serialize(writer, i);
    writer.Close();
}

private void DeserializeObject(string filename) {
    XmlSerializer serializer = new XmlSerializer
        (typeof(OrderedItem), "http://www.cpandl.com");
    // A FileStream is needed to read the XML document.
    FileStream fs = new FileStream(filename, FileMode.Open);

    // Declare an object variable of the type to be deserialized.
    OrderedItem i;

    // Deserialize the object.
    i = (OrderedItem) serializer.Deserialize(fs);

    // Insert code to use the properties and methods of the object.
}

Private Sub SerializeObject(ByVal filename As String)
    Dim serializer As New XmlSerializer(GetType(OrderedItem), _
                                          "http://www.cpandl.com")
    
    ' Create an instance of the class to be serialized.
    Dim i As New OrderedItem()
    
    ' Insert code to set property values.
    ' Writing the document requires a TextWriter.
    Dim writer As New StreamWriter(filename)
    ' Serialize the object, and close the TextWriter.
    serializer.Serialize(writer, i)
    writer.Close()
End Sub


Private Sub DeserializeObject(ByVal filename As String)
    Dim serializer As New XmlSerializer(GetType(OrderedItem), _
                                          "http://www.cpandl.com")
    ' A FileStream is needed to read the XML document.
    Dim fs As New FileStream(filename, FileMode.Open)
    
    ' Declare an object variable of the type to be deserialized.
    Dim i As OrderedItem
    
    ' Deserialize the object.
    i = CType(serializer.Deserialize(fs), OrderedItem)
    ' Insert code to use the properties and methods of the object.
End Sub

Confira também

• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(Type ^ type, cli::array <Type ^> ^ extraTypes);

public XmlSerializer (Type type, Type[] extraTypes);

public XmlSerializer (Type type, Type[]? extraTypes);

new System.Xml.Serialization.XmlSerializer : Type * Type[] -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, extraTypes As Type())

Parâmetros

Exemplos

O exemplo a seguir serializa uma instância de uma classe que contém um campo público que retorna uma matriz de objetos. O extraTypes parâmetro do XmlSerializer construtor especifica os tipos dos objetos que podem ser serializados na matriz.

#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Serialization;
ref class Address;
ref class Phone;

// This defines the object that will be serialized.
public ref class Teacher
{
public:
   String^ Name;
   Teacher(){}

   /* Note that the Info field returns an array of objects.
         Any object can be added to the array by adding the
         object type to the array passed to the extraTypes argument. */

   [XmlArray(ElementName="ExtraInfo",IsNullable=true)]
   array<Object^>^Info;
   Phone^ PhoneInfo;
};


// This defines one of the extra types to be included.
public ref class Address
{
public:
   String^ City;
   Address(){}

   Address( String^ city )
   {
      City = city;
   }
};

// Another extra type to include.
public ref class Phone
{
public:
   String^ PhoneNumber;
   Phone(){}

   Phone( String^ phoneNumber )
   {
      PhoneNumber = phoneNumber;
   }
};

// Another type, derived from Phone
public ref class InternationalPhone: public Phone
{
public:
   String^ CountryCode;
   InternationalPhone(){}

   InternationalPhone( String^ countryCode )
   {
      CountryCode = countryCode;
   }
};

public ref class Run
{
public:
   static void main()
   {
      Run^ test = gcnew Run;
      test->SerializeObject( "Teacher.xml" );
      test->DeserializeObject( "Teacher.xml" );
   }

private:
   void SerializeObject( String^ filename )
   {
      // Writing the file requires a TextWriter.
      TextWriter^ myStreamWriter = gcnew StreamWriter( filename );

      // Create a Type array.
      array<Type^>^extraTypes = gcnew array<Type^>(3);
      extraTypes[ 0 ] = Address::typeid;
      extraTypes[ 1 ] = Phone::typeid;
      extraTypes[ 2 ] = InternationalPhone::typeid;

      // Create the XmlSerializer instance.
      XmlSerializer^ mySerializer = gcnew XmlSerializer( Teacher::typeid,extraTypes );
      Teacher^ teacher = gcnew Teacher;
      teacher->Name = "Mike";

      // Add extra types to the Teacher object
      array<Object^>^info = gcnew array<Object^>(2);
      info[ 0 ] = gcnew Address( "Springville" );
      info[ 1 ] = gcnew Phone( "555-0100" );
      teacher->Info = info;
      teacher->PhoneInfo = gcnew InternationalPhone( "000" );
      mySerializer->Serialize( myStreamWriter, teacher );
      myStreamWriter->Close();
   }

   void DeserializeObject( String^ filename )
   {
      // Create a Type array.
      array<Type^>^extraTypes = gcnew array<Type^>(3);
      extraTypes[ 0 ] = Address::typeid;
      extraTypes[ 1 ] = Phone::typeid;
      extraTypes[ 2 ] = InternationalPhone::typeid;

      // Create the XmlSerializer instance.
      XmlSerializer^ mySerializer = gcnew XmlSerializer( Teacher::typeid,extraTypes );

      // Reading a file requires a FileStream.
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
      Teacher^ teacher = dynamic_cast<Teacher^>(mySerializer->Deserialize( fs ));

      // Read the extra information.
      Address^ a = dynamic_cast<Address^>(teacher->Info[ 0 ]);
      Phone^ p = dynamic_cast<Phone^>(teacher->Info[ 1 ]);
      InternationalPhone^ Ip = dynamic_cast<InternationalPhone^>(teacher->PhoneInfo);
      Console::WriteLine( teacher->Name );
      Console::WriteLine( a->City );
      Console::WriteLine( p->PhoneNumber );
      Console::WriteLine( Ip->CountryCode );
   }
};

int main()
{
   Run::main();
}

using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;

// This defines the object that will be serialized.
public class Teacher
{
   public string Name;
   public Teacher(){}
   /* Note that the Info field returns an array of objects.
      Any object can be added to the array by adding the
      object type to the array passed to the extraTypes argument. */
   [XmlArray (ElementName = "ExtraInfo", IsNullable = true)]
   public object[] Info;
   public Phone PhoneInfo;
}

// This defines one of the extra types to be included.
public class Address
{
   public string City;

   public Address(){}
   public Address(string city)
   {
      City = city;
   }
}

// Another extra type to include.
public class Phone
{
   public string PhoneNumber;
   public Phone(){}
   public Phone(string phoneNumber)
   {
      PhoneNumber = phoneNumber;
   }
}

// Another type, derived from Phone
public class InternationalPhone:Phone
{
   public string CountryCode;

   public InternationalPhone(){}

   public InternationalPhone(string countryCode)
   {
      CountryCode = countryCode;
   }
}

public class Run
{
   public static void Main()
   {
      Run test = new Run();
      test.SerializeObject("Teacher.xml");
      test.DeserializeObject("Teacher.xml");
   }

   private void SerializeObject(string filename)
   {
      // Writing the file requires a TextWriter.
      TextWriter myStreamWriter = new StreamWriter(filename);

      // Create a Type array.
      Type [] extraTypes= new Type[3];
      extraTypes[0] = typeof(Address);
      extraTypes[1] = typeof(Phone);
      extraTypes[2] = typeof(InternationalPhone);

      // Create the XmlSerializer instance.
      XmlSerializer mySerializer = new XmlSerializer
      (typeof(Teacher),extraTypes);

      Teacher teacher = new Teacher();
      teacher.Name = "Mike";
      // Add extra types to the Teacher object
      object [] info = new object[2];
      info[0] = new Address("Springville");
      info[1] = new Phone("555-0100");

      teacher.Info = info;

      teacher.PhoneInfo = new InternationalPhone("000");

      mySerializer.Serialize(myStreamWriter,teacher);
      myStreamWriter.Close();
   }

   private void DeserializeObject(string filename)
   {
      // Create a Type array.
      Type [] extraTypes= new Type[3];
      extraTypes[0] = typeof(Address);
      extraTypes[1] = typeof(Phone);
      extraTypes[2] = typeof(InternationalPhone);

      // Create the XmlSerializer instance.
      XmlSerializer mySerializer = new XmlSerializer
      (typeof(Teacher),extraTypes);

      // Reading a file requires a FileStream.
      FileStream fs = new FileStream(filename, FileMode.Open);
      Teacher teacher = (Teacher) mySerializer.Deserialize(fs);

      // Read the extra information.
      Address a = (Address)teacher.Info[0];
      Phone p = (Phone) teacher.Info[1];
      InternationalPhone Ip =
      (InternationalPhone) teacher.PhoneInfo;

      Console.WriteLine(teacher.Name);
      Console.WriteLine(a.City);
      Console.WriteLine(p.PhoneNumber);
      Console.WriteLine(Ip.CountryCode);
   }
}

Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization



' This defines the object that will be serialized.
Public Class Teacher
    Public Name As String
    
    Public Sub New()
    End Sub
    ' Note that the Info field returns an array of objects.
    ' Any object can be added to the array by adding the
    ' object type to the array passed to the extraTypes argument. 
    <XmlArray(ElementName := "ExtraInfo", IsNullable := True)> _
    Public Info() As Object
    Public PhoneInfo As Phone
End Class


' This defines one of the extra types to be included.
Public Class Address
    Public City As String
    
    Public Sub New()
    End Sub
    
    Public Sub New(city As String)
        me.City = city
    End Sub
End Class
 

' Another extra type to include.
Public Class Phone
    Public PhoneNumber As String
    
    Public Sub New()
    End Sub
    
    Public Sub New(phoneNumber As String)
        me.PhoneNumber = phoneNumber
    End Sub
End Class


' Another type, derived from Phone.
Public Class InternationalPhone
    Inherits Phone
    Public CountryCode As String
    
    
    Public Sub New()
    End Sub
     
    Public Sub New(countryCode As String)
        me.CountryCode = countryCode
    End Sub
End Class


Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("Teacher.xml")
        test.DeserializeObject("Teacher.xml")
    End Sub
    
    
    Private Sub SerializeObject(filename As String)
        ' Writing the file requires a TextWriter.
        Dim myStreamWriter As New StreamWriter(filename)
        
        ' Create a Type array.
        Dim extraTypes(2) As Type
        extraTypes(0) = GetType(Address)
        extraTypes(1) = GetType(Phone)
        extraTypes(2) = GetType(InternationalPhone)
        
        ' Create the XmlSerializer instance.
        Dim mySerializer As New XmlSerializer(GetType(Teacher), extraTypes)
        
        Dim teacher As New Teacher()
        teacher.Name = "Mike"
        ' Add extra types to the Teacher object.
        Dim info(1) As Object
        info(0) = New Address("Springville")
        info(1) = New Phone("555-0100")
        
        teacher.Info = info
        
        teacher.PhoneInfo = New InternationalPhone("000")
        
        mySerializer.Serialize(myStreamWriter, teacher)
        myStreamWriter.Close()
    End Sub
    
    
    Private Sub DeserializeObject(filename As String)
        ' Create a Type array.
        Dim extraTypes(2) As Type
        extraTypes(0) = GetType(Address)
        extraTypes(1) = GetType(Phone)
        extraTypes(2) = GetType(InternationalPhone)
        
        ' Create the XmlSerializer instance.
        Dim mySerializer As New XmlSerializer(GetType(Teacher), extraTypes)
        
        ' Reading a file requires a FileStream.
        Dim fs As New FileStream(filename, FileMode.Open)
        Dim teacher As Teacher = CType(mySerializer.Deserialize(fs), Teacher)
        
        ' Read the extra information.
        Dim a As Address = CType(teacher.Info(0), Address)
        Dim p As Phone = CType(teacher.Info(1), Phone)
        Dim Ip As InternationalPhone = CType(teacher.PhoneInfo, InternationalPhone)
        
        Console.WriteLine(teacher.Name)
        Console.WriteLine(a.City)
        Console.WriteLine(p.PhoneNumber)
        Console.WriteLine(Ip.CountryCode)
    End Sub
End Class

Comentários

Por padrão, se uma propriedade pública ou campo retornar um objeto ou matriz de objetos, os tipos de objeto serão serializados automaticamente. No entanto, se uma classe contiver um campo ou uma propriedade que retorna uma matriz de tipo Object, qualquer objeto poderá ser inserido nessa matriz. Nesse caso, deve XmlSerializer ser instruído a esperar todos os tipos de objeto possíveis inseridos na Object matriz. Para fazer isso, use o extraTypes parâmetro para especificar os tipos de objeto extras para serializar ou desserializar.

Você também pode usar o extraTypes parâmetro para especificar tipos derivados de uma classe base. Por exemplo, suponha que exista uma classe base nomeada Phone e uma classe nomeada InternationalPhone deriva dela. Use o extraTypes parâmetro para especificar o tipo derivado também.

Confira também

• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(Type ^ type, System::Xml::Serialization::XmlAttributeOverrides ^ overrides);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides overrides);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides? overrides);

new System.Xml.Serialization.XmlSerializer : Type * System.Xml.Serialization.XmlAttributeOverrides -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, overrides As XmlAttributeOverrides)

Parâmetros

Exemplos

O exemplo a seguir serializa uma instância de uma classe definida em uma DLL e, para isso, substitui os membros públicos encontrados na DLL.

// Beginning of HighSchool.dll
#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Serialization;

namespace HighSchool
{
   public ref class Student
   {
   public:
      String^ Name;
      int ID;
   };

   public ref class MyClass
   {
   public:
      array<Student^>^Students;
   };
}

namespace College
{

using namespace HighSchool;
   public ref class Graduate: public HighSchool::Student
   {
   public:
      Graduate(){}

      // Add a new field named University.
      String^ University;
   };

   public ref class Run
   {
   public:
      static void main()
      {
         Run^ test = gcnew Run;
         test->WriteOverriddenAttributes( "College.xml" );
         test->ReadOverriddenAttributes( "College.xml" );
      }

   private:
      void WriteOverriddenAttributes( String^ filename )
      {
         // Writing the file requires a TextWriter.
         TextWriter^ myStreamWriter = gcnew StreamWriter( filename );

         // Create an XMLAttributeOverrides class.
         XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;

         // Create the XmlAttributes class.
         XmlAttributes^ attrs = gcnew XmlAttributes;

         /* Override the Student class. "Alumni" is the name
               of the overriding element in the XML output. */
         XmlElementAttribute^ attr = gcnew XmlElementAttribute( "Alumni",Graduate::typeid );

         /* Add the XmlElementAttribute to the collection of
               elements in the XmlAttributes object. */
         attrs->XmlElements->Add( attr );

         /* Add the XmlAttributes to the XmlAttributeOverrides. 
               "Students" is the name being overridden. */
         attrOverrides->Add( HighSchool::MyClass::typeid, "Students", attrs );

         // Create the XmlSerializer. 
         XmlSerializer^ mySerializer = gcnew XmlSerializer( HighSchool::MyClass::typeid,attrOverrides );
         MyClass ^ myClass = gcnew MyClass;
         Graduate^ g1 = gcnew Graduate;
         g1->Name = "Jackie";
         g1->ID = 1;
         g1->University = "Alma Mater";
         Graduate^ g2 = gcnew Graduate;
         g2->Name = "Megan";
         g2->ID = 2;
         g2->University = "CM";
         array<Student^>^myArray = {g1,g2};
         myClass->Students = myArray;
         mySerializer->Serialize( myStreamWriter, myClass );
         myStreamWriter->Close();
      }

      void ReadOverriddenAttributes( String^ filename )
      {
         /* The majority of the code here is the same as that in the
               WriteOverriddenAttributes method. Because the XML being read
               doesn't conform to the schema defined by the DLL, the
               XMLAttributesOverrides must be used to create an 
               XmlSerializer instance to read the XML document.*/
         XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;
         XmlAttributes^ attrs = gcnew XmlAttributes;
         XmlElementAttribute^ attr = gcnew XmlElementAttribute( "Alumni",Graduate::typeid );
         attrs->XmlElements->Add( attr );
         attrOverrides->Add( HighSchool::MyClass::typeid, "Students", attrs );
         XmlSerializer^ readSerializer = gcnew XmlSerializer( HighSchool::MyClass::typeid,attrOverrides );
         
         // To read the file, a FileStream object is required. 
         FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
         MyClass ^ myClass;
         myClass = dynamic_cast<MyClass^>(readSerializer->Deserialize( fs ));

         /* Here is the difference between reading and writing an 
               XML document: You must declare an object of the derived 
               type (Graduate) and cast the Student instance to it.*/
         Graduate^ g;
         System::Collections::IEnumerator^ myEnum = myClass->Students->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            Graduate^ grad = safe_cast<Graduate^>(myEnum->Current);
            g = dynamic_cast<Graduate^>(grad);
            Console::Write( "{0}\t", g->Name );
            Console::Write( "{0}\t", g->ID );
            Console::Write( "{0}\n", g->University );
         }
      }
   };
}

int main()
{
   College::Run::main();
}

// Beginning of HighSchool.dll
namespace HighSchool
{
   public class Student
   {
      public string Name;
      public int ID;
   }

   public class MyClass
   {
      public Student[] Students;
   }
}

namespace College
   {
   using System;
   using System.IO;
   using System.Xml;
   using System.Xml.Serialization;
   using HighSchool;

    public class Graduate:HighSchool.Student
    {
       public Graduate(){}
       // Add a new field named University.
       public string University;
    }

   public class Run
   {
      public static void Main()
      {
         Run test = new Run();
         test.WriteOverriddenAttributes("College.xml");
         test.ReadOverriddenAttributes("College.xml");
      }

      private void WriteOverriddenAttributes(string filename)
      {
         // Writing the file requires a TextWriter.
         TextWriter myStreamWriter = new StreamWriter(filename);
         // Create an XMLAttributeOverrides class.
         XmlAttributeOverrides attrOverrides =
         new XmlAttributeOverrides();
         // Create the XmlAttributes class.
         XmlAttributes attrs = new XmlAttributes();

         /* Override the Student class. "Alumni" is the name
         of the overriding element in the XML output. */
         XmlElementAttribute attr =
         new XmlElementAttribute("Alumni", typeof(Graduate));

         /* Add the XmlElementAttribute to the collection of
         elements in the XmlAttributes object. */
         attrs.XmlElements.Add(attr);

         /* Add the XmlAttributes to the XmlAttributeOverrides.
         "Students" is the name being overridden. */
         attrOverrides.Add(typeof(HighSchool.MyClass),
         "Students", attrs);

         // Create the XmlSerializer.
         XmlSerializer mySerializer = new XmlSerializer
         (typeof(HighSchool.MyClass), attrOverrides);

         MyClass myClass = new MyClass();

         Graduate g1 = new Graduate();
         g1.Name = "Jackie";
         g1.ID = 1;
         g1.University = "Alma Mater";

         Graduate g2 = new Graduate();
         g2.Name = "Megan";
         g2.ID = 2;
         g2.University = "CM";

         Student[] myArray = {g1,g2};
         myClass.Students = myArray;

         mySerializer.Serialize(myStreamWriter, myClass);
         myStreamWriter.Close();
      }

      private void ReadOverriddenAttributes(string filename)
      {
         /* The majority of the code here is the same as that in the
         WriteOverriddenAttributes method. Because the XML being read
         doesn't conform to the schema defined by the DLL, the
         XMLAttributesOverrides must be used to create an
         XmlSerializer instance to read the XML document.*/

         XmlAttributeOverrides attrOverrides = new
         XmlAttributeOverrides();
         XmlAttributes attrs = new XmlAttributes();
         XmlElementAttribute attr =
         new XmlElementAttribute("Alumni", typeof(Graduate));
         attrs.XmlElements.Add(attr);
         attrOverrides.Add(typeof(HighSchool.MyClass),
         "Students", attrs);

         XmlSerializer readSerializer = new XmlSerializer
         (typeof(HighSchool.MyClass), attrOverrides);

         // To read the file, a FileStream object is required.
         FileStream fs = new FileStream(filename, FileMode.Open);

         MyClass myClass;

         myClass = (MyClass) readSerializer.Deserialize(fs);

         /* Here is the difference between reading and writing an
         XML document: You must declare an object of the derived
         type (Graduate) and cast the Student instance to it.*/
         Graduate g;

         foreach(Graduate grad in myClass.Students)
         {
            g = (Graduate) grad;
            Console.Write(g.Name + "\t");
            Console.Write(g.ID + "\t");
            Console.Write(g.University + "\n");
         }
      }
   }
}

' Beginning of HighSchool.dll
Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization
Imports HighSchool

Namespace HighSchool
    
    Public Class Student
        Public Name As String
        Public ID As Integer
    End Class
    
    
    Public Class MyClass1
        Public Students() As Student
    End Class
End Namespace 'HighSchool

Namespace College
    Public Class Graduate
        Inherits HighSchool.Student
        
        Public Sub New()
        End Sub
        Public University As String
    End Class
    
    
    
    Public Class Run
        
        Public Shared Sub Main()
            Dim test As New Run()
            test.WriteOverriddenAttributes("College.xml")
            test.ReadOverriddenAttributes("College.xml")
        End Sub
        
        
        Private Sub WriteOverriddenAttributes(filename As String)
            ' Writing the file requires a TextWriter.
            Dim myStreamWriter As New StreamWriter(filename)
            ' Create an XMLAttributeOverrides class.
            Dim attrOverrides As New XmlAttributeOverrides()
            ' Create the XmlAttributes class.
            Dim attrs As New XmlAttributes()
            
            ' Override the Student class. "Alumni" is the name
            ' of the overriding element in the XML output. 
            Dim attr As New XmlElementAttribute("Alumni", GetType(Graduate))
            
            ' Add the XmlElementAttribute to the collection of
            ' elements in the XmlAttributes object. 
            attrs.XmlElements.Add(attr)
            
            ' Add the XmlAttributes to the XmlAttributeOverrides. 
            ' "Students" is the name being overridden. 
            attrOverrides.Add(GetType(HighSchool.MyClass1), "Students", attrs)
            
            ' Create the XmlSerializer. 
            Dim mySerializer As New XmlSerializer(GetType(HighSchool.MyClass1), attrOverrides)
            
            Dim oMyClass As New MyClass1()
            
            Dim g1 As New Graduate()
            g1.Name = "Jackie"
            g1.ID = 1
            g1.University = "Alma Mater"
            
            Dim g2 As New Graduate()
            g2.Name = "Megan"
            g2.ID = 2
            g2.University = "CM"
            
            Dim myArray As Student() =  {g1, g2}
            oMyClass.Students = myArray
            
            mySerializer.Serialize(myStreamWriter, oMyClass)
            myStreamWriter.Close()
        End Sub
        
        
        Private Sub ReadOverriddenAttributes(filename As String)
            ' The majority of the code here is the same as that in the
            ' WriteOverriddenAttributes method. Because the XML being read
            ' doesn't conform to the schema defined by the DLL, the
            ' XMLAttributesOverrides must be used to create an
            ' XmlSerializer instance to read the XML document.
            
            Dim attrOverrides As New XmlAttributeOverrides()
            Dim attrs As New XmlAttributes()
            Dim attr As New XmlElementAttribute("Alumni", GetType(Graduate))
            attrs.XmlElements.Add(attr)
            attrOverrides.Add(GetType(HighSchool.MyClass1), "Students", attrs)
            
            Dim readSerializer As New XmlSerializer(GetType(HighSchool.MyClass1), attrOverrides)
            
            ' To read the file, a FileStream object is required. 
            Dim fs As New FileStream(filename, FileMode.Open)
            
            Dim oMyClass As MyClass1
            
            oMyClass = CType(readSerializer.Deserialize(fs), MyClass1)
            
            ' Here is the difference between reading and writing an
            ' XML document: You must declare an object of the derived
            ' type (Graduate) and cast the Student instance to it.
            Dim g As Graduate
            
            Dim grad As Graduate
            For Each grad In  oMyClass.Students
                g = CType(grad, Graduate)
                Console.Write((g.Name & ControlChars.Tab))
                Console.Write((g.ID.ToString & ControlChars.Tab))
                Console.Write((g.University & ControlChars.Cr))
            Next grad
        End Sub
    End Class
End Namespace 'College

Comentários

O overrides parâmetro pode ser usado para controlar como campos e propriedades são codificados em XML. Essas configurações substituem todos os atributos que já existem nos objetos. Isso pode ser útil quando o código-fonte não pode ser modificado ou várias codificações são necessárias para as mesmas classes.

Confira também

• XmlAttributeOverrides
• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(Type ^ type, System::Xml::Serialization::XmlRootAttribute ^ root);

public XmlSerializer (Type type, System.Xml.Serialization.XmlRootAttribute root);

public XmlSerializer (Type type, System.Xml.Serialization.XmlRootAttribute? root);

new System.Xml.Serialization.XmlSerializer : Type * System.Xml.Serialization.XmlRootAttribute -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, root As XmlRootAttribute)

Parâmetros

Exemplos

O exemplo a seguir constrói um XmlSerializer que usa uma XmlRootAttribute que contém várias propriedades do elemento raiz XML, como o namespace e o nome do elemento.

private:
   void SerializeObject( String^ filename )
   {
      // Create an XmlRootAttribute, and set its properties.
      XmlRootAttribute^ xRoot = gcnew XmlRootAttribute;
      xRoot->ElementName = "CustomRoot";
      xRoot->Namespace = "http://www.cpandl.com";
      xRoot->IsNullable = true;

      // Construct the XmlSerializer with the XmlRootAttribute.
      XmlSerializer^ serializer = gcnew XmlSerializer(
         OrderedItem::typeid,xRoot );

      // Create an instance of the object to serialize.
      OrderedItem^ i = gcnew OrderedItem;
      // Insert code to set properties of the ordered item.

      // Writing the document requires a TextWriter.
      TextWriter^ writer = gcnew StreamWriter( filename );
      serializer->Serialize( writer, i );
      writer->Close();
   }

   void DeserializeObject( String^ filename )
   {
      // Create an XmlRootAttribute, and set its properties.
      XmlRootAttribute^ xRoot = gcnew XmlRootAttribute;
      xRoot->ElementName = "CustomRoot";
      xRoot->Namespace = "http://www.cpandl.com";
      xRoot->IsNullable = true;

      XmlSerializer^ serializer = gcnew XmlSerializer(
         OrderedItem::typeid,xRoot );

      // A FileStream is needed to read the XML document.
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
      // Deserialize the object.
      OrderedItem^ i = dynamic_cast<OrderedItem^>(serializer->Deserialize( fs ));
      // Insert code to use the object's properties and methods.
   }

private void SerializeObject(string filename) {
    // Create an XmlRootAttribute, and set its properties.
    XmlRootAttribute xRoot = new XmlRootAttribute();
    xRoot.ElementName = "CustomRoot";
    xRoot.Namespace = "http://www.cpandl.com";
    xRoot.IsNullable = true;

    // Construct the XmlSerializer with the XmlRootAttribute.
    XmlSerializer serializer = new XmlSerializer
        (typeof(OrderedItem),xRoot);

    // Create an instance of the object to serialize.
    OrderedItem i = new OrderedItem();
    // Insert code to set properties of the ordered item.

    // Writing the document requires a TextWriter.
    TextWriter writer = new StreamWriter(filename);

    serializer.Serialize(writer, i);
    writer.Close();
}

private void DeserializeObject(string filename) {
    // Create an XmlRootAttribute, and set its properties.
    XmlRootAttribute xRoot = new XmlRootAttribute();
    xRoot.ElementName = "CustomRoot";
    xRoot.Namespace = "http://www.cpandl.com";
    xRoot.IsNullable = true;

    XmlSerializer serializer = new XmlSerializer
        (typeof(OrderedItem),xRoot);

    // A FileStream is needed to read the XML document.
    FileStream fs = new FileStream(filename, FileMode.Open);
    // Deserialize the object.
    OrderedItem i = (OrderedItem) serializer.Deserialize(fs);
    // Insert code to use the object's properties and methods.
}

Private Sub SerializeObject(ByVal filename As String)
    ' Create an XmlRootAttribute, and set its properties.
    Dim xRoot As New XmlRootAttribute()
    xRoot.ElementName = "CustomRoot"
    xRoot.Namespace = "http://www.cpandl.com"
    xRoot.IsNullable = True
    
    ' Construct the XmlSerializer with the XmlRootAttribute.
    Dim serializer As New XmlSerializer(GetType(OrderedItem), xRoot)
    
    ' Create an instance of the object to serialize.
    Dim i As New OrderedItem()
    ' Insert code to set properties of the ordered item.
    ' Writing the document requires a TextWriter.
    Dim writer As New StreamWriter(filename)
    
    serializer.Serialize(writer, i)
    writer.Close()
End Sub
    
Private Sub DeserializeObject(ByVal filename As String)
    ' Create an XmlRootAttribute, and set its properties.
    Dim xRoot As New XmlRootAttribute()
    xRoot.ElementName = "CustomRoot"
    xRoot.Namespace = "http://www.cpandl.com"
    xRoot.IsNullable = True
    
    Dim serializer As New XmlSerializer(GetType(OrderedItem), xRoot)
    
    ' A FileStream is needed to read the XML document.
    Dim fs As New FileStream(filename, FileMode.Open)
    ' Deserialize the object.
    Dim i As OrderedItem = CType(serializer.Deserialize(fs), OrderedItem)
    ' Insert code to use the object's properties and methods.
End Sub

Comentários

O elemento raiz de um documento XML inclui todos os outros elementos. Por padrão, o objeto especificado pelo type parâmetro é serializado como o elemento raiz. Propriedades, como o nome do elemento XML do elemento raiz, são retiradas do type objeto. No entanto, o root parâmetro permite que você substitua as informações do objeto padrão especificando um XmlRootAttribute; o objeto permite que você defina um namespace diferente, um nome de elemento e assim por diante.

Confira também

• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(Type ^ type, System::Xml::Serialization::XmlAttributeOverrides ^ overrides, cli::array <Type ^> ^ extraTypes, System::Xml::Serialization::XmlRootAttribute ^ root, System::String ^ defaultNamespace);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides overrides, Type[] extraTypes, System.Xml.Serialization.XmlRootAttribute root, string defaultNamespace);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides? overrides, Type[]? extraTypes, System.Xml.Serialization.XmlRootAttribute? root, string? defaultNamespace);

new System.Xml.Serialization.XmlSerializer : Type * System.Xml.Serialization.XmlAttributeOverrides * Type[] * System.Xml.Serialization.XmlRootAttribute * string -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, overrides As XmlAttributeOverrides, extraTypes As Type(), root As XmlRootAttribute, defaultNamespace As String)

Parâmetros

Exemplos

O exemplo a seguir serializa uma instância de uma classe definida em uma DLL e, para isso, substitui os membros públicos encontrados na classe. O exemplo também especifica uma matriz de tipos extras, o namespace padrão para todos os elementos XML e a classe a ser usada que fornece as informações do elemento raiz XML. O exemplo pressupõe que o código no início foi compilado em uma DLL chamada HighSchool.

// Beginning of the HighSchool.dll 
#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Xml::Serialization;

namespace HighSchool
{
   public ref class Student
   {
   public:
      String^ Name;
      int ID;
   };

   public ref class MyClass
   {
   public:
      array<Student^>^Students;
   };
}

namespace College
{

using namespace HighSchool;
   public ref class Graduate: public HighSchool::Student
   {
   public:
      Graduate(){}

      // Add a new field named University.
      String^ University;

      // Use extra types to use this field.
      array<Object^>^Info;
   };

   public ref class Address
   {
   public:
      String^ City;
   };

   public ref class Phone
   {
   public:
      String^ Number;
   };

   public ref class Run
   {
   public:
      static void main()
      {
         Run^ test = gcnew Run;
         test->WriteOverriddenAttributes( "College.xml" );
         test->ReadOverriddenAttributes( "College.xml" );
      }

   private:
      void WriteOverriddenAttributes( String^ filename )
      {
         // Writing the file requires a TextWriter.
         TextWriter^ myStreamWriter = gcnew StreamWriter( filename );

         // Create an XMLAttributeOverrides class.
         XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;

         // Create the XmlAttributes class.
         XmlAttributes^ attrs = gcnew XmlAttributes;

         /* Override the Student class. "Alumni" is the name
               of the overriding element in the XML output. */
         XmlElementAttribute^ attr = gcnew XmlElementAttribute( "Alumni",Graduate::typeid );

         /* Add the XmlElementAttribute to the collection of
               elements in the XmlAttributes object. */
         attrs->XmlElements->Add( attr );

         /* Add the XmlAttributes to the XmlAttributeOverrides. 
               "Students" is the name being overridden. */
         attrOverrides->Add( HighSchool::MyClass::typeid, "Students", attrs );

         // Create array of extra types.
         array<Type^>^extraTypes = gcnew array<Type^>(2);
         extraTypes[ 0 ] = Address::typeid;
         extraTypes[ 1 ] = Phone::typeid;

         // Create an XmlRootAttribute.
         XmlRootAttribute^ root = gcnew XmlRootAttribute( "Graduates" );

         /* Create the XmlSerializer with the 
               XmlAttributeOverrides object. */
         XmlSerializer^ mySerializer = gcnew XmlSerializer( HighSchool::MyClass::typeid,attrOverrides,extraTypes,root,"http://www.microsoft.com" );
         MyClass ^ myClass = gcnew MyClass;
         Graduate^ g1 = gcnew Graduate;
         g1->Name = "Jacki";
         g1->ID = 1;
         g1->University = "Alma";
         Graduate^ g2 = gcnew Graduate;
         g2->Name = "Megan";
         g2->ID = 2;
         g2->University = "CM";
         array<Student^>^myArray = {g1,g2};
         myClass->Students = myArray;

         // Create extra information.
         Address^ a1 = gcnew Address;
         a1->City = "Ionia";
         Address^ a2 = gcnew Address;
         a2->City = "Stamford";
         Phone^ p1 = gcnew Phone;
         p1->Number = "555-0101";
         Phone^ p2 = gcnew Phone;
         p2->Number = "555-0100";
         array<Object^>^o1 = {a1,p1};
         array<Object^>^o2 = {a2,p2};
         g1->Info = o1;
         g2->Info = o2;
         mySerializer->Serialize( myStreamWriter, myClass );
         myStreamWriter->Close();
      }

      void ReadOverriddenAttributes( String^ filename )
      {
         /* The majority of the code here is the same as that in the
               WriteOverriddenAttributes method. Because the XML being read
               doesn't conform to the schema defined by the DLL, the
               XMLAttributesOverrides must be used to create an 
               XmlSerializer instance to read the XML document.*/
         XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;
         XmlAttributes^ attrs = gcnew XmlAttributes;
         XmlElementAttribute^ attr = gcnew XmlElementAttribute( "Alumni",Graduate::typeid );
         attrs->XmlElements->Add( attr );
         attrOverrides->Add( HighSchool::MyClass::typeid, "Students", attrs );
         array<Type^>^extraTypes = gcnew array<Type^>(2);
         extraTypes[ 0 ] = Address::typeid;
         extraTypes[ 1 ] = Phone::typeid;
         XmlRootAttribute^ root = gcnew XmlRootAttribute( "Graduates" );
         XmlSerializer^ readSerializer = gcnew XmlSerializer( HighSchool::MyClass::typeid,attrOverrides,extraTypes,root,"http://www.microsoft.com" );

         // A FileStream object is required to read the file. 
         FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
         MyClass ^ myClass;
         myClass = dynamic_cast<MyClass^>(readSerializer->Deserialize( fs ));
         
         /* Here is the difference between reading and writing an 
               XML document: You must declare an object of the derived 
               type (Graduate) and cast the Student instance to it.*/
         Graduate^ g;
         Address^ a;
         Phone^ p;
         System::Collections::IEnumerator^ myEnum = myClass->Students->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            Graduate^ grad = safe_cast<Graduate^>(myEnum->Current);
            g = dynamic_cast<Graduate^>(grad);
            Console::Write( "{0}\t", g->Name );
            Console::Write( "{0}\t", g->ID );
            Console::Write( "{0}\n", g->University );
            a = dynamic_cast<Address^>(g->Info[ 0 ]);
            Console::WriteLine( a->City );
            p = dynamic_cast<Phone^>(g->Info[ 1 ]);
            Console::WriteLine( p->Number );
         }
      }
   };
}

int main()
{
   College::Run::main();
}

// Beginning of the HighSchool.dll

namespace HighSchool
{
   public class Student
   {
      public string Name;
      public int ID;
   }

   public class MyClass
   {
      public Student[] Students;
   }
}

namespace College
   {
   using System;
   using System.IO;
   using System.Xml;
   using System.Xml.Serialization;
   using HighSchool;

    public class Graduate:HighSchool.Student
    {
       public Graduate(){}
       // Add a new field named University.
       public string University;
       // Use extra types to use this field.
       public object[]Info;
    }

    public class Address
    {
       public string City;
    }

    public class Phone
    {
       public string Number;
    }

   public class Run
   {
      public static void Main()
      {
         Run test = new Run();
         test.WriteOverriddenAttributes("College.xml");
         test.ReadOverriddenAttributes("College.xml");
      }

      private void WriteOverriddenAttributes(string filename)
      {
         // Writing the file requires a TextWriter.
         TextWriter myStreamWriter = new StreamWriter(filename);
         // Create an XMLAttributeOverrides class.
         XmlAttributeOverrides attrOverrides =
         new XmlAttributeOverrides();
         // Create the XmlAttributes class.
         XmlAttributes attrs = new XmlAttributes();
         /* Override the Student class. "Alumni" is the name
         of the overriding element in the XML output. */

         XmlElementAttribute attr =
         new XmlElementAttribute("Alumni", typeof(Graduate));
         /* Add the XmlElementAttribute to the collection of
         elements in the XmlAttributes object. */
         attrs.XmlElements.Add(attr);
         /* Add the XmlAttributes to the XmlAttributeOverrides.
         "Students" is the name being overridden. */
         attrOverrides.Add(typeof(HighSchool.MyClass),
         "Students", attrs);

         // Create array of extra types.
         Type [] extraTypes = new Type[2];
         extraTypes[0]=typeof(Address);
         extraTypes[1]=typeof(Phone);

         // Create an XmlRootAttribute.
         XmlRootAttribute root = new XmlRootAttribute("Graduates");

         /* Create the XmlSerializer with the
         XmlAttributeOverrides object. */
         XmlSerializer mySerializer = new XmlSerializer
         (typeof(HighSchool.MyClass), attrOverrides, extraTypes,
         root, "http://www.microsoft.com");

         MyClass myClass= new MyClass();

         Graduate g1 = new Graduate();
         g1.Name = "Jacki";
         g1.ID = 1;
         g1.University = "Alma";

         Graduate g2 = new Graduate();
         g2.Name = "Megan";
         g2.ID = 2;
         g2.University = "CM";

         Student[] myArray = {g1,g2};

         myClass.Students = myArray;

         // Create extra information.
         Address a1 = new Address();
         a1.City = "Ionia";
         Address a2 = new Address();
         a2.City = "Stamford";
         Phone p1 = new Phone();
         p1.Number = "555-0101";
         Phone p2 = new Phone();
         p2.Number = "555-0100";

         Object[]o1 = new Object[2]{a1, p1};
         Object[]o2 = new Object[2]{a2,p2};

         g1.Info = o1;
         g2.Info = o2;
         mySerializer.Serialize(myStreamWriter,myClass);
         myStreamWriter.Close();
      }

      private void ReadOverriddenAttributes(string filename)
      {
         /* The majority of the code here is the same as that in the
         WriteOverriddenAttributes method. Because the XML being read
         doesn't conform to the schema defined by the DLL, the
         XMLAttributesOverrides must be used to create an
         XmlSerializer instance to read the XML document.*/

         XmlAttributeOverrides attrOverrides = new
         XmlAttributeOverrides();
         XmlAttributes attrs = new XmlAttributes();
         XmlElementAttribute attr =
         new XmlElementAttribute("Alumni", typeof(Graduate));
         attrs.XmlElements.Add(attr);
         attrOverrides.Add(typeof(HighSchool.MyClass),
         "Students", attrs);

         Type [] extraTypes = new Type[2];
         extraTypes[0] = typeof(Address);
         extraTypes[1] = typeof(Phone);

         XmlRootAttribute root = new XmlRootAttribute("Graduates");

         XmlSerializer readSerializer = new XmlSerializer
         (typeof(HighSchool.MyClass), attrOverrides, extraTypes,
         root, "http://www.microsoft.com");

         // A FileStream object is required to read the file.
         FileStream fs = new FileStream(filename, FileMode.Open);

         MyClass myClass;
         myClass = (MyClass) readSerializer.Deserialize(fs);

         /* Here is the difference between reading and writing an
         XML document: You must declare an object of the derived
         type (Graduate) and cast the Student instance to it.*/
         Graduate g;
         Address a;
         Phone p;
         foreach(Graduate grad in myClass.Students)
         {
            g = (Graduate) grad;
            Console.Write(g.Name + "\t");
            Console.Write(g.ID + "\t");
            Console.Write(g.University + "\n");
            a = (Address) g.Info[0];
            Console.WriteLine(a.City);
            p = (Phone) g.Info[1];
            Console.WriteLine(p.Number);
         }
      }
   }
}

'Beginning of the HighSchool.dll 
Imports System.IO
Imports System.Xml
Imports System.Xml.Serialization

' Imports HighSchool

Namespace HighSchool

    Public Class Student
        Public Name As String
        Public ID As Integer
    End Class


    Public Class ClassRoom
        Public Students() As Student
    End Class
End Namespace 'HighSchool

Namespace College
    Public Class Graduate
        Inherits HighSchool.Student

        Public Sub New()
        End Sub
        ' Add a new field named University.
        Public University As String
        ' Use extra types to use this field.
        Public Info() As Object
    End Class


    Public Class Address
        Public City As String
    End Class


    Public Class Phone
        Public Number As String
    End Class


    Public Class Run

        Public Shared Sub Main()
            Dim test As New Run()
            test.WriteOverriddenAttributes("College.xml")
            test.ReadOverriddenAttributes("College.xml")
        End Sub


        Private Sub WriteOverriddenAttributes(ByVal filename As String)
            ' Writing the file requires a TextWriter.
            Dim myStreamWriter As New StreamWriter(filename)
            ' Create an XMLAttributeOverrides class.
            Dim attrOverrides As New XmlAttributeOverrides()
            ' Create the XmlAttributes class.
            Dim attrs As New XmlAttributes()
            ' Override the Student class. "Alumni" is the name
            ' of the overriding element in the XML output. 

            Dim attr As New XmlElementAttribute("Alumni", GetType(Graduate))
            ' Add the XmlElementAttribute to the collection of
            ' elements in the XmlAttributes object. 
            attrs.XmlElements.Add(attr)
            ' Add the XmlAttributes to the XmlAttributeOverrides.
            ' "Students" is the name being overridden. 
            attrOverrides.Add(GetType(HighSchool.ClassRoom), "Students", attrs)

            ' Create array of extra types.
            Dim extraTypes(1) As Type
            extraTypes(0) = GetType(Address)
            extraTypes(1) = GetType(Phone)

            ' Create an XmlRootAttribute.
            Dim root As New XmlRootAttribute("Graduates")

            ' Create the XmlSerializer with the
            ' XmlAttributeOverrides object. 
            Dim mySerializer As New XmlSerializer(GetType(HighSchool.ClassRoom), _
                attrOverrides, extraTypes, root, "http://www.microsoft.com")

            Dim oMyClass As New HighSchool.ClassRoom()

            Dim g1 As New Graduate()
            g1.Name = "Jacki"
            g1.ID = 1
            g1.University = "Alma"

            Dim g2 As New Graduate()
            g2.Name = "Megan"
            g2.ID = 2
            g2.University = "CM"

            Dim myArray As HighSchool.Student() = {g1, g2}

            oMyClass.Students = myArray

            ' Create extra information.
            Dim a1 As New Address()
            a1.City = "Ionia"
            Dim a2 As New Address()
            a2.City = "Stamford"
            Dim p1 As New Phone()
            p1.Number = "555-0101"
            Dim p2 As New Phone()
            p2.Number = "555-0100"

            Dim o1() As Object = {a1, p1}
            Dim o2() As Object = {a2, p2}

            g1.Info = o1
            g2.Info = o2
            mySerializer.Serialize(myStreamWriter, oMyClass)
            myStreamWriter.Close()
        End Sub


        Private Sub ReadOverriddenAttributes(ByVal filename As String)
            ' The majority of the code here is the same as that in the
            ' WriteOverriddenAttributes method. Because the XML being read
            ' doesn't conform to the schema defined by the DLL, the
            ' XMLAttributesOverrides must be used to create an
            ' XmlSerializer instance to read the XML document.

            Dim attrOverrides As New XmlAttributeOverrides()
            Dim attrs As New XmlAttributes()
            Dim attr As New XmlElementAttribute("Alumni", GetType(Graduate))
            attrs.XmlElements.Add(attr)
            attrOverrides.Add(GetType(HighSchool.ClassRoom), "Students", attrs)

            Dim extraTypes(1) As Type
            extraTypes(0) = GetType(Address)
            extraTypes(1) = GetType(Phone)

            Dim root As New XmlRootAttribute("Graduates")

            Dim readSerializer As New XmlSerializer(GetType(HighSchool.ClassRoom), _
                attrOverrides, extraTypes, root, "http://www.microsoft.com")

            ' A FileStream object is required to read the file. 
            Dim fs As New FileStream(filename, FileMode.Open)

            Dim oMyClass As HighSchool.ClassRoom
            oMyClass = CType(readSerializer.Deserialize(fs), HighSchool.ClassRoom)

            ' Here is the difference between reading and writing an
            ' XML document: You must declare an object of the derived
            ' type (Graduate) and cast the Student instance to it.
            Dim g As Graduate
            Dim a As Address
            Dim p As Phone
            Dim grad As Graduate
            For Each grad In oMyClass.Students
                g = CType(grad, Graduate)
                Console.Write((g.Name & ControlChars.Tab))
                Console.Write((g.ID & ControlChars.Tab))
                Console.Write((g.University & ControlChars.Cr))
                a = CType(g.Info(0), Address)
                Console.WriteLine(a.City)
                p = CType(g.Info(1), Phone)
                Console.WriteLine(p.Number)
            Next grad
        End Sub
    End Class
End Namespace 'College

Comentários

O overrides parâmetro permite a criação de um XmlSerializer que serializa uma classe que estende ou substitui o comportamento de uma classe base. Por exemplo, considerando uma DLL, é possível criar uma classe que herda ou estende uma classe contida na DLL. Para serializar essa classe, você deve usar uma instância da XmlAttributeOverrides classe ao construir a XmlSerializer. Para obter mais detalhes, confira XmlAttributeOverrides.

Por padrão, se uma propriedade pública ou campo retornar um objeto ou matriz de objetos, os tipos de objeto serão serializados automaticamente. No entanto, se uma classe contiver um campo ou uma propriedade que retorna uma matriz de tipo Object, qualquer objeto poderá ser inserido nessa matriz. Nesse caso, deve XmlSerializer ser instruído a esperar todos os tipos de objeto possíveis inseridos na Object matriz. Para fazer isso, use o extraTypes parâmetro para especificar os tipos de objeto extras para serializar ou desserializar.

O elemento raiz de um documento XML inclui todos os outros elementos. Por padrão, o objeto especificado pelo type parâmetro é serializado como o elemento raiz. Propriedades, como o nome do elemento XML do elemento raiz, são retiradas do type objeto. No entanto, o root parâmetro permite que você substitua as informações do objeto padrão especificando um XmlRootAttribute; o objeto permite que você defina um namespace diferente, um nome de elemento e assim por diante.

Use o defaultName parâmetro para especificar o namespace padrão de todos os elementos XML gerados pelo XmlSerializer.

Confira também

• XmlAttributeOverrides
• XmlRootAttribute
• XmlAttributes
• Apresentando a serialização XML
• Como especificar um nome de elemento alternativo para um fluxo XML
• Controlando a serialização XML usando atributos
• Exemplos de Serialização XML
• Ferramenta de Definição de Esquema XML (Xsd.exe)

public:
 XmlSerializer(Type ^ type, System::Xml::Serialization::XmlAttributeOverrides ^ overrides, cli::array <Type ^> ^ extraTypes, System::Xml::Serialization::XmlRootAttribute ^ root, System::String ^ defaultNamespace, System::String ^ location);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides? overrides, Type[]? extraTypes, System.Xml.Serialization.XmlRootAttribute? root, string? defaultNamespace, string? location);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides overrides, Type[] extraTypes, System.Xml.Serialization.XmlRootAttribute root, string defaultNamespace, string location);

new System.Xml.Serialization.XmlSerializer : Type * System.Xml.Serialization.XmlAttributeOverrides * Type[] * System.Xml.Serialization.XmlRootAttribute * string * string -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, overrides As XmlAttributeOverrides, extraTypes As Type(), root As XmlRootAttribute, defaultNamespace As String, location As String)

Parâmetros

public:
 XmlSerializer(Type ^ type, System::Xml::Serialization::XmlAttributeOverrides ^ overrides, cli::array <Type ^> ^ extraTypes, System::Xml::Serialization::XmlRootAttribute ^ root, System::String ^ defaultNamespace, System::String ^ location, System::Security::Policy::Evidence ^ evidence);

public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides overrides, Type[] extraTypes, System.Xml.Serialization.XmlRootAttribute root, string defaultNamespace, string location, System.Security.Policy.Evidence evidence);

[System.Obsolete("This method is obsolete and will be removed in a future release of the .NET Framework. Please use a XmlSerializer constructor overload which does not take an Evidence parameter. See http://go2.microsoft.com/fwlink/?LinkId=131738 for more information.")]
public XmlSerializer (Type type, System.Xml.Serialization.XmlAttributeOverrides overrides, Type[] extraTypes, System.Xml.Serialization.XmlRootAttribute root, string defaultNamespace, string location, System.Security.Policy.Evidence evidence);

new System.Xml.Serialization.XmlSerializer : Type * System.Xml.Serialization.XmlAttributeOverrides * Type[] * System.Xml.Serialization.XmlRootAttribute * string * string * System.Security.Policy.Evidence -> System.Xml.Serialization.XmlSerializer

[<System.Obsolete("This method is obsolete and will be removed in a future release of the .NET Framework. Please use a XmlSerializer constructor overload which does not take an Evidence parameter. See http://go2.microsoft.com/fwlink/?LinkId=131738 for more information.")>]
new System.Xml.Serialization.XmlSerializer : Type * System.Xml.Serialization.XmlAttributeOverrides * Type[] * System.Xml.Serialization.XmlRootAttribute * string * string * System.Security.Policy.Evidence -> System.Xml.Serialization.XmlSerializer

Public Sub New (type As Type, overrides As XmlAttributeOverrides, extraTypes As Type(), root As XmlRootAttribute, defaultNamespace As String, location As String, evidence As Evidence)

Parâmetros

Atributos

ObsoleteAttribute

Comentários

Permite um controle mais preciso sobre o acesso a um diretório temporário e impede a injeção e a exploração de código. Para usar esse método, especifique um local e forneça acesso somente a usuários específicos. Os administradores podem configurar políticas com listas de evidências que correspondem a evidências com permissões.