Defines the member of a type that is the default member used by InvokeMember.
Namespace:
System.Reflection
Assembly:
mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
<AttributeUsageAttribute(AttributeTargets.Class Or AttributeTargets.Struct Or AttributeTargets.Interface)> _
Public NotInheritable Class DefaultMemberAttribute _
Inherits Attribute
Dim instance As DefaultMemberAttribute
[SerializableAttribute]
[ComVisibleAttribute(true)]
[AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Struct|AttributeTargets.Interface)]
public sealed class DefaultMemberAttribute : Attribute
[SerializableAttribute]
[ComVisibleAttribute(true)]
[AttributeUsageAttribute(AttributeTargets::Class|AttributeTargets::Struct|AttributeTargets::Interface)]
public ref class DefaultMemberAttribute sealed : public Attribute
public final class DefaultMemberAttribute extends Attribute
A property is imported as an indexer (default indexed property in Visual Basic) if the property has arguments and if the name of the property or one of its accessors matches the name specified by the DefaultMemberAttribute. If the DefaultMemberAttribute is not present on the containing type, then the type does not have an indexer. The C# compiler emits the DefaultMemberAttribute on any type containing an indexer. In C# it is an error to manually attribute a type with the DefaultMemberAttribute if the type also declares an indexer.
The following example uses the DefaultMemberAttribute attribute to make the Age property the default member of the MyClass class.
Imports System
Imports System.Reflection
Imports System.IO
Imports Microsoft.VisualBasic
<DefaultMemberAttribute("Age")> Public Class [MyClass]
Public Sub Name(ByVal s As String)
End Sub 'Name
Public ReadOnly Property Age() As Integer
Get
Return 20
End Get
End Property
Public Shared Sub Main()
Try
Dim myType As Type = GetType([MyClass])
Dim memberInfoArray As MemberInfo() = myType.GetDefaultMembers()
If memberInfoArray.Length > 0 Then
Dim memberInfoObj As MemberInfo
For Each memberInfoObj In memberInfoArray
Console.WriteLine("The default member name is: " + memberInfoObj.ToString())
Next memberInfoObj
Else
Console.WriteLine("No default members are available.")
End If
Catch e As InvalidOperationException
Console.WriteLine("InvalidOperationException: " + e.Message)
Catch e As IOException
Console.WriteLine("IOException: " + e.Message)
Catch e As Exception
Console.WriteLine("Exception: " + e.Message)
End Try
End Sub 'Main
End Class '[MyClass]
using System;
using System.Reflection;
using System.IO;
[DefaultMemberAttribute("Age")]
public class MyClass
{
public void Name(String s) {}
public int Age
{
get
{
return 20;
}
}
public static void Main()
{
try
{
Type myType = typeof(MyClass);
MemberInfo[] memberInfoArray = myType.GetDefaultMembers();
if (memberInfoArray.Length > 0)
{
foreach(MemberInfo memberInfoObj in memberInfoArray)
{
Console.WriteLine("The default member name is: " + memberInfoObj.ToString());
}
}
else
{
Console.WriteLine("No default members are available.");
}
}
catch(InvalidOperationException e)
{
Console.WriteLine("InvalidOperationException: " + e.Message);
}
catch(IOException e)
{
Console.WriteLine("IOException: " + e.Message);
}
catch(Exception e)
{
Console.WriteLine("Exception: " + e.Message);
}
}
}
using namespace System;
using namespace System::Reflection;
using namespace System::IO;
[DefaultMemberAttribute("Age")]
public ref class MyClass
{
public:
void Name( String^ s ){}
property int Age
{
int get()
{
return 20;
}
}
};
int main()
{
try
{
Type^ myType = MyClass::typeid;
array<MemberInfo^>^memberInfoArray = myType->GetDefaultMembers();
if ( memberInfoArray->Length > 0 )
{
System::Collections::IEnumerator^ myEnum = memberInfoArray->GetEnumerator();
while ( myEnum->MoveNext() )
{
MemberInfo^ memberInfoObj = safe_cast<MemberInfo^>(myEnum->Current);
Console::WriteLine( "The default member name is: {0}", memberInfoObj );
}
}
else
{
Console::WriteLine( "No default members are available." );
}
}
catch ( InvalidOperationException^ e )
{
Console::WriteLine( "InvalidOperationException: {0}", e->Message );
}
catch ( IOException^ e )
{
Console::WriteLine( "IOException: {0}", e->Message );
}
catch ( Exception^ e )
{
Console::WriteLine( "Exception: {0}", e->Message );
}
}
System..::.Object
System..::.Attribute
System.Reflection..::.DefaultMemberAttribute
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference