XmlArrayItemAttribute Classe

Définition

public ref class XmlArrayItemAttribute : Attribute

[System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property | System.AttributeTargets.ReturnValue, AllowMultiple=true)]
public class XmlArrayItemAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property | System.AttributeTargets.ReturnValue, AllowMultiple=true)>]
type XmlArrayItemAttribute = class
    inherit Attribute

Public Class XmlArrayItemAttribute
Inherits Attribute

Héritage

Object

Attribute

XmlArrayItemAttribute

Attributs

AttributeUsageAttribute

Exemples

L’exemple suivant sérialise une classe nommée Group qui contient un champ nommé Employees qui retourne un tableau d’objets Employee . L’exemple applique le XmlArrayItemAttribute champ, en indiquant ainsi qu’il XmlSerializer peut insérer des objets du type de classe de base (Employee) et du type de classe dérivée (Manager) dans le tableau sérialisé.

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

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

public ref class Employee
{
public:
   String^ Name;
};

public ref class Manager: public Employee
{
public:
   int Level;
};

public ref class Group
{
public:

   /* The XmlArrayItemAttribute allows the XmlSerializer to insert
      both the base type (Employee) and derived type (Manager) 
      into serialized arrays. */

   [XmlArrayItem(Manager::typeid),
   XmlArrayItem(Employee::typeid)]
   array<Employee^>^Employees;

   /* Use the XmlArrayItemAttribute to specify types allowed
      in an array of Object items. */

   [XmlArray]
   [XmlArrayItem(Int32::typeid,
   ElementName="MyNumber"),
   XmlArrayItem(String::typeid,
   ElementName="MyString"),
   XmlArrayItem(Manager::typeid)]
   array<Object^>^ExtraInfo;
};

void SerializeObject( String^ filename )
{
   // Creates a new XmlSerializer.
   XmlSerializer^ s = gcnew XmlSerializer( Group::typeid );

   // Writing the XML file to disk requires a TextWriter.
   TextWriter^ writer = gcnew StreamWriter( filename );
   Group^ group = gcnew Group;
   Manager^ manager = gcnew Manager;
   Employee^ emp1 = gcnew Employee;
   Employee^ emp2 = gcnew Employee;
   manager->Name = "Consuela";
   manager->Level = 3;
   emp1->Name = "Seiko";
   emp2->Name = "Martina";
   array<Employee^>^emps = {manager,emp1,emp2};
   group->Employees = emps;

   // Creates an int and a string and assigns to ExtraInfo.
   array<Object^>^temp = {43,"Extra",manager};
   group->ExtraInfo = temp;

   // Serializes the object, and closes the StreamWriter.
   s->Serialize( writer, group );
   writer->Close();
}

void DeserializeObject( String^ filename )
{
   FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
   XmlSerializer^ x = gcnew XmlSerializer( Group::typeid );
   Group^ g = dynamic_cast<Group^>(x->Deserialize( fs ));
   Console::WriteLine( "Members:" );
   System::Collections::IEnumerator^ myEnum = g->Employees->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Employee^ e = safe_cast<Employee^>(myEnum->Current);
      Console::WriteLine( "\t{0}", e->Name );
   }
}

int main()
{
   SerializeObject( "TypeDoc.xml" );
   DeserializeObject( "TypeDoc.xml" );
}

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

public class Group
{
   /* The XmlArrayItemAttribute allows the XmlSerializer to insert
      both the base type (Employee) and derived type (Manager)
      into serialized arrays. */

   [XmlArrayItem(typeof(Manager)),
   XmlArrayItem(typeof(Employee))]
   public Employee[] Employees;

   /* Use the XmlArrayItemAttribute to specify types allowed
      in an array of Object items. */
   [XmlArray]
   [XmlArrayItem (typeof(int),
   ElementName = "MyNumber"),
   XmlArrayItem (typeof(string),
   ElementName = "MyString"),
   XmlArrayItem(typeof(Manager))]
   public object [] ExtraInfo;
}

public class Employee
{
   public string Name;
}

public class Manager:Employee{
   public int Level;
}

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

   public void SerializeObject(string filename)
   {
      // Creates a new XmlSerializer.
      XmlSerializer s = new XmlSerializer(typeof(Group));

      // Writing the XML file to disk requires a TextWriter.
      TextWriter writer = new StreamWriter(filename);
      Group group = new Group();

      Manager manager = new Manager();
      Employee emp1 = new Employee();
      Employee emp2 = new Employee();
      manager.Name = "Consuela";
      manager.Level = 3;
      emp1.Name = "Seiko";
      emp2.Name = "Martina";
      Employee [] emps = new Employee[3]{manager, emp1, emp2};
      group.Employees = emps;

      // Creates an int and a string and assigns to ExtraInfo.
      group.ExtraInfo = new Object[3]{43, "Extra", manager};

      // Serializes the object, and closes the StreamWriter.
      s.Serialize(writer, group);
      writer.Close();
   }

   public void DeserializeObject(string filename)
   {
      FileStream fs = new FileStream(filename, FileMode.Open);
      XmlSerializer x = new XmlSerializer(typeof(Group));
      Group g = (Group) x.Deserialize(fs);
      Console.WriteLine("Members:");

      foreach(Employee e in g.Employees)
      {
         Console.WriteLine("\t" + e.Name);
      }
   }
}

Option Explicit
Option Strict

Imports System.IO
Imports System.Xml.Serialization

Public Class Group
    ' The XmlArrayItemAttribute allows the XmlSerializer to insert
    ' both the base type (Employee) and derived type (Manager)
    ' into serialized arrays. 
    
    <XmlArrayItem(GetType(Manager)), _
     XmlArrayItem(GetType(Employee))> _
    Public Employees() As Employee
    
    ' Use the XmlArrayItemAttribute to specify types allowed
    ' in an array of Object items. 
    <XmlArray(), _
     XmlArrayItem(GetType(Integer), ElementName := "MyNumber"), _
     XmlArrayItem(GetType(String), ElementName := "MyString"), _
     XmlArrayItem(GetType(Manager))> _
    Public ExtraInfo() As Object
End Class

Public Class Employee
    Public Name As String
End Class

Public Class Manager
    Inherits Employee
    Public Level As Integer
End Class


Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("TypeDoc.xml")
        test.DeserializeObject("TypeDoc.xml")
    End Sub
    
       
    Public Sub SerializeObject(ByVal filename As String)
        ' Creates a new XmlSerializer.
        Dim s As New XmlSerializer(GetType(Group))
        
        ' Writing the XML file to disk requires a TextWriter.
        Dim writer As New StreamWriter(filename)
        Dim group As New Group()
        
        Dim manager As New Manager()
        Dim emp1 As New Employee()
        Dim emp2 As New Employee()
        manager.Name = "Consuela"
        manager.Level = 3
        emp1.Name = "Seiko"
        emp2.Name = "Martina"
        Dim emps() As Employee = {manager, emp1, emp2}
        group.Employees = emps
        
        ' Creates an int and a string and assigns to ExtraInfo.
        group.ExtraInfo = New Object() {43, "Extra", manager}
        
        ' Serializes the object, and closes the StreamWriter.
        s.Serialize(writer, group)
        writer.Close()
    End Sub
    
    
    Public Sub DeserializeObject(ByVal filename As String)
        Dim fs As New FileStream(filename, FileMode.Open)
        Dim x As New XmlSerializer(GetType(Group))
        Dim g As Group = CType(x.Deserialize(fs), Group)
        Console.WriteLine("Members:")
        
        Dim e As Employee
        For Each e In  g.Employees
            Console.WriteLine(ControlChars.Tab & e.Name)
        Next e
    End Sub
End Class

Remarques

Il XmlArrayItemAttribute appartient à une famille d’attributs qui contrôle la XmlSerializer sérialisation ou la désérialisation d’un objet. Pour obtenir la liste complète des attributs similaires, consultez Attributs qui contrôlent la sérialisation XML.

Vous pouvez appliquer le XmlArrayItemAttribute membre en lecture/écriture public qui retourne un tableau ou fournit l’accès à celui-ci. Par exemple, un champ qui retourne un tableau d’objets, une collection, une ArrayListclasse ou une classe qui implémente l’interface IEnumerable .

En d’autres termes, le XmlArrayItemAttribute polymorphisme prend en charge l’ajout XmlSerializer d’objets dérivés à un tableau. Par exemple, supposons qu’une classe nommée Mammal soit dérivée d’une classe de base nommée Animal. Supposons également qu’une classe nommée MyAnimals contient un champ qui retourne un tableau d’objets Animal . Pour permettre la XmlSerializer sérialisation à la fois du type et Mammal du Animal type, appliquez XmlArrayItemAttribute le champ deux fois, chaque fois que vous spécifiez l’un des deux types acceptables.

Pour plus d’informations sur l’utilisation d’attributs, consultez Attributs.

Constructeurs

Propriétés

Méthodes

Implémentations d’interfaces explicites

S’applique à

Voir aussi

• XmlArrayAttribute
• XmlSerializer
• XmlArrayItems
• XmlAttributeOverrides
• XmlAttributes
• Introduction à la sérialisation XML
• Comment : spécifier un nom d'élément différent pour un flux XML
• Contrôle de la sérialisation XML à l'aide d'attributs
• Exemples de sérialisation XML
• Outil XML Schema Definition (Xsd.exe)