Exibindo informações de tipo

  • Artigo

The System.Type classe é fundamental para reflexão. O common linguagem tempo de execução cria o Tipo para um tipo carregado quando solicita reflexão.Você pode usar um Tipo objeto métodos, campos, propriedades e classes aninhadas para descobrir tudo a respeito desse tipo.

Use Assembly.GetType ou Assembly.GetTypes Para obter Tipo objetos de módulos (assemblies) que não foram carregados, passando o nome do tipo ou tipos que você deseja.Use Type.GetType Para obter o Tipo objetos de um assembly que já está carregado.Use Module.GetType e Module.GetTypes Para obter o módulo Tipo objetos.

Observação:

Se você quiser examinar e manipular tipos genéricos e métodos, consulte as informações adicionais fornecidas no Reflexão e tipos genéricos and Como: Examinar e instanciar tipos genéricos com reflexão.

O exemplo a seguir mostra a sintaxe necessária para obter o Assembly objeto e o módulo para um assembly.

' Gets the mscorlib assembly in which the object is defined.
Dim a As Reflection.Assembly = GetType(Object).Module.Assembly

// Gets the mscorlib assembly in which the object is defined.
Assembly a = typeof(Object).Module.Assembly;

O exemplo a seguir demonstra como obter Tipo objetos de um assembly carregado.

' Loads an assembly using its file name.
Dim a As Reflection.Assembly = Reflection.Assembly.LoadFrom("MyExe.exe")
' Gets the type names from the assembly.
Dim types2 As Type() = a.GetTypes()
Dim t As Type
For Each t In  types2
    Console.WriteLine(t.FullName)
Next t

// Loads an assembly using its file name.
Assembly a = Assembly.LoadFrom ("MyExe.exe");
// Gets the type names from the assembly.
Type [] types2 = a.GetTypes ();
foreach (Type t in types2)
{
    Console.WriteLine (t.FullName);
}

Depois de obter um Tipo, você pode descobrir informações sobre os membros desse tipo de várias maneiras.Por exemplo, você pode descobrir sobre todos os membros do tipo chamando o Type.GetMembers método, que obtém uma matriz de MemberInfo objetos que descreve cada um dos membros do tipo corrente.

Você também pode usar métodos sobre o Tipo classe para recuperar informações sobre um ou mais construtores, métodos, eventos, campos ou propriedades que você especifique por nome.Por exemplo, Type.GetConstructor encapsula um construtor específico da classe corrente.

Se você tiver um Tipo, você pode usar o Type.Module propriedade para obter um objeto que encapsula o módulo que contém esse tipo. Use o Module.Assembly propriedade para localizar um objeto que encapsula o assembly que contém o módulo. Você pode obter o assembly que encapsula o tipo diretamente, usando o Type.Assembly propriedade.

sistema.Type e ConstructorInfo

O exemplo a seguir mostra como lista construtores para uma classe, nesse caso, a String classe.

' This program lists all the public constructors 
' of the System.String class.
Imports System
Imports System.Reflection
Class ListMembers
    Public Shared Sub Main()
        Dim t As Type = GetType(String)
        Console.WriteLine("Listing all the public constructors of the {0} type", t)
        ' Constructors.
        Dim ci As ConstructorInfo() = t.GetConstructors((BindingFlags.Public Or BindingFlags.Instance))
        Console.WriteLine("//Constructors")
        PrintMembers(ci)
    End Sub
    Public Shared Sub PrintMembers(ms() As MemberInfo)
        Dim m As MemberInfo
        For Each m In ms
            Console.WriteLine("{0}{1}", "     ", m)
        Next m
        Console.WriteLine()
    End Sub
End Class

// This program lists all the public constructors 
// of the System.String class.
using System;
using System.Reflection;
class ListMembers {
    public static void Main(String[] args) {
        Type t = typeof(System.String);
        Console.WriteLine ("Listing all the public constructors of the {0} type", t);
        // Constructors.
        ConstructorInfo[] ci = t.GetConstructors(BindingFlags.Public | BindingFlags.Instance);
        Console.WriteLine ("//Constructors");
        PrintMembers (ci);
    }
    public static void PrintMembers(MemberInfo [] ms) {
        foreach (MemberInfo m in ms) {
            Console.WriteLine ("{0}{1}", "     ", m);
        }
        Console.WriteLine();
    }
}

MemberInfo, MethodInfo, FieldInfo e PropertyInfo

Obter informações sobre o tipo métodos, propriedades, eventos e campos usando MemberInfo, MethodInfo, FieldInfo, ou PropertyInfo objetos.

O exemplo a seguir utiliza MemberInfo para lista o número de membros no sistema.IO.arquivo classe e usa o sistema.Type.IsPublic propriedade para determinar a visibilidade da classe.

Option Explicit
Option Strict
Imports System
Imports System.IO
Imports System.Reflection
Imports Microsoft.VisualBasic
Class Mymemberinfo
    Public Shared Sub Main()
        Console.WriteLine(ControlChars.Cr & "Reflection.MemberInfo")
        ' Gets the Type and MemberInfo.
        Dim MyType As Type = Type.GetType("System.IO.File")
        Dim Mymemberinfoarray As MemberInfo() = MyType.GetMembers()
        ' Gets and displays the DeclaringType method. 
        Console.WriteLine(ControlChars.Cr & "There are {0} members in {1}.", Mymemberinfoarray.Length, MyType.FullName)
        Console.WriteLine("{0}.", MyType.FullName)
        If MyType.IsPublic Then
            Console.WriteLine("{0} is public.", MyType.FullName)
        End If
    End Sub
End Class

using System;
using System.IO;
using System.Reflection;

class Mymemberinfo
{ 
    public static void Main(string[] args)
    { 
        Console.WriteLine ("\nReflection.MemberInfo");
        // Gets the Type and MemberInfo.
        Type MyType =Type.GetType("System.IO.File");
        MemberInfo[] Mymemberinfoarray = MyType.GetMembers(); 
        // Gets and displays the DeclaringType method. 
        Console.WriteLine("\nThere are {0} members in {1}.", 
            Mymemberinfoarray.Length, MyType.FullName);
        Console.WriteLine("{0}.", MyType.FullName); 
        if (MyType.IsPublic)
        {
            Console.WriteLine("{0} is public.", MyType.FullName);
        }
    }
}

O exemplo a seguir investiga o tipo do membro especificado.Ele executa reflexão em um membro do MemberInfo classe e lista seu tipo.

' This code displays information about the GetValue method of FieldInfo.
Option Explicit
Option Strict
Imports System
Imports System.Reflection
Class MyMethodInfo
    Public Shared Sub Main()
        Console.WriteLine("Reflection.MethodInfo")
        ' Gets and displays the Type.
        Dim MyType As Type = Type.GetType("System.Reflection.FieldInfo")
        ' Specifies the member for which you want type information.
        Dim Mymethodinfo As MethodInfo = MyType.GetMethod("GetValue")
        Console.WriteLine((MyType.FullName & "." & Mymethodinfo.Name))
        ' Gets and displays the MemberType property.
        Dim Mymembertypes As MemberTypes = Mymethodinfo.MemberType
        If MemberTypes.Constructor = Mymembertypes Then
            Console.WriteLine("MemberType is of type All")
        ElseIf MemberTypes.Custom = Mymembertypes Then
            Console.WriteLine("MemberType is of type Custom")
        ElseIf MemberTypes.Event = Mymembertypes Then
            Console.WriteLine("MemberType is of type Event")
        ElseIf MemberTypes.Field = Mymembertypes Then
            Console.WriteLine("MemberType is of type Field")
        ElseIf MemberTypes.Method = Mymembertypes Then
            Console.WriteLine("MemberType is of type Method")
        ElseIf MemberTypes.Property = Mymembertypes Then
            Console.WriteLine("MemberType is of type Property")
        ElseIf MemberTypes.TypeInfo = Mymembertypes Then
            Console.WriteLine("MemberType is of type TypeInfo")
        End If
        Return
    End Sub
End Class

// This code displays information about the GetValue method of FieldInfo.
using System;
using System.Reflection;
class MyMethodInfo {
    public static int Main() {
        Console.WriteLine("Reflection.MethodInfo");
        // Gets and displays the Type.
        Type MyType = Type.GetType("System.Reflection.FieldInfo");
        // Specifies the member for which you want type information.
        MethodInfo Mymethodinfo = MyType.GetMethod("GetValue");
        Console.WriteLine(MyType.FullName + "." + Mymethodinfo.Name);
        // Gets and displays the MemberType property.
        MemberTypes Mymembertypes = Mymethodinfo.MemberType;
        if (MemberTypes.Constructor == Mymembertypes) {
            Console.WriteLine("MemberType is of type All"); 
        }
        else if (MemberTypes.Custom == Mymembertypes) {
            Console.WriteLine("MemberType is of type Custom"); 
        }
        else if (MemberTypes.Event == Mymembertypes) {
            Console.WriteLine("MemberType is of type Event"); 
        }
        else if (MemberTypes.Field == Mymembertypes) {
            Console.WriteLine("MemberType is of type Field"); 
        }
        else if (MemberTypes.Method == Mymembertypes) {
            Console.WriteLine("MemberType is of type Method"); 
        }
        else if (MemberTypes.Property == Mymembertypes) {
            Console.WriteLine("MemberType is of type Property"); 
        }
        else if (MemberTypes.TypeInfo == Mymembertypes) {
            Console.WriteLine("MemberType is of type TypeInfo"); 
        }
        return 0;
    }
}

O exemplo a seguir usa todos os de reflexão * Informações classes de comBindingFlags Para listar todos os membros (construtores, campos, propriedades, eventos e métodos) da classe especificada, dividindo as categorias de instância e os membros em estático.

' This program lists all the members of the 
' System.IO.BufferedStream class.
Imports System
Imports System.IO
Imports System.Reflection
Imports Microsoft.VisualBasic
Class ListMembers
    Public Shared Sub Main()
        ' Specifies the class.
        Dim t As Type = GetType(System.IO.BufferedStream)
        Console.WriteLine("Listing all the members (public and non public) of the {0} type", t)
        ' Lists static fields first.
        Dim fi As FieldInfo() = t.GetFields((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Fields")
        PrintMembers(fi)
        ' Static properties.
        Dim pi As PropertyInfo() = t.GetProperties((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Properties")
        PrintMembers(pi)
        ' Static events.
        Dim ei As EventInfo() = t.GetEvents((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Events")
        PrintMembers(ei)
        ' Static methods.
        Dim mi As MethodInfo() = t.GetMethods((BindingFlags.Static Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Static Methods")
        PrintMembers(mi)
        ' Constructors.
        Dim ci As ConstructorInfo() = t.GetConstructors((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Constructors")
        PrintMembers(ci)
        ' Instance fields.
        fi = t.GetFields((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Fields")
        PrintMembers(fi)
        ' Instance properites.
        pi = t.GetProperties((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Properties")
        PrintMembers(pi)
        ' Instance events.
        ei = t.GetEvents((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Events")
        PrintMembers(ei)
        ' Instance methods.
        mi = t.GetMethods((BindingFlags.Instance Or BindingFlags.NonPublic Or BindingFlags.Public))
        Console.WriteLine("// Instance Methods")
        PrintMembers(mi)
        Console.WriteLine(ControlChars.CrLf & "Press ENTER to exit.")
        Console.Read()
    End Sub
    Public Shared Sub PrintMembers(ms() As MemberInfo)
        Dim m As MemberInfo
        For Each m In  ms
            Console.WriteLine("{0}{1}", "     ", m)
        Next m
        Console.WriteLine()
    End Sub
End Class

// This program lists all the members of the 
// System.IO.BufferedStream class.
using System;
using System.IO;
using System.Reflection;

class ListMembers {
    public static void Main(String[] args) {
        // Specifies the class.
        Type t = typeof (System.IO.BufferedStream);
        Console.WriteLine ("Listing all the members (public and non public) of the {0} type", t);

        // Lists static fields first.
        FieldInfo [] fi = t.GetFields (BindingFlags.Static | 
         BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine ("// Static Fields");
        PrintMembers (fi);

        // Static properties.
        PropertyInfo [] pi = t.GetProperties (BindingFlags.Static | 
         BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine ("// Static Properties");
        PrintMembers (pi);

        // Static events.
        EventInfo [] ei = t.GetEvents (BindingFlags.Static | 
         BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine ("// Static Events");
        PrintMembers (ei);

        // Static methods.
        MethodInfo [] mi = t.GetMethods (BindingFlags.Static | 
         BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine ("// Static Methods");
        PrintMembers (mi);

        // Constructors.
        ConstructorInfo [] ci = t.GetConstructors (BindingFlags.Instance | 
         BindingFlags.NonPublic | BindingFlags.Public);
        Console.WriteLine ("// Constructors");
        PrintMembers (ci);

        // Instance fields.
        fi = t.GetFields (BindingFlags.Instance | BindingFlags.NonPublic | 
         BindingFlags.Public);
        Console.WriteLine ("// Instance Fields");
        PrintMembers (fi);

        // Instance properites.
        pi = t.GetProperties (BindingFlags.Instance | BindingFlags.NonPublic | 
         BindingFlags.Public);
        Console.WriteLine ("// Instance Properties");
        PrintMembers (pi);

        // Instance events.
        ei = t.GetEvents (BindingFlags.Instance | BindingFlags.NonPublic | 
         BindingFlags.Public);
        Console.WriteLine ("// Instance Events");
        PrintMembers (ei);

        // Instance methods.
        mi = t.GetMethods (BindingFlags.Instance | BindingFlags.NonPublic   
         | BindingFlags.Public);
        Console.WriteLine ("// Instance Methods");
        PrintMembers (mi);

        Console.WriteLine ("\r\nPress ENTER to exit.");
        Console.Read();
    }

    public static void PrintMembers (MemberInfo [] ms) {
        foreach (MemberInfo m in ms) {
            Console.WriteLine ("{0}{1}", "     ", m);
        }
        Console.WriteLine();
    }
}

Consulte também

Referência

Exibindo informações de tipo

BindingFlags

Assembly.GetType

Assembly.GetTypes

Type.GetType

Type.GetMembers

Type.GetFields

Module.GetType

Module.GetTypes

MemberInfo

ConstructorInfo

MethodInfo

FieldInfo

EventInfo

ParameterInfo

Outros recursos

Reflexão e tipos genérico