ComDefaultInterfaceAttribute Class (System.Runtime.InteropServices)

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Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

ComDefaultInterfaceAttribute Class

Specifies a default interface to expose to COM. This class cannot be inherited.

Namespace: System.Runtime.InteropServices
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic (Declaration)

<AttributeUsageAttribute(AttributeTargets.Class, Inherited := False)> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class ComDefaultInterfaceAttribute _
    Inherits Attribute

Visual Basic (Usage)

Dim instance As ComDefaultInterfaceAttribute

[AttributeUsageAttribute(AttributeTargets.Class, Inherited = false)]
[ComVisibleAttribute(true)]
public sealed class ComDefaultInterfaceAttribute : Attribute

Visual C++

[AttributeUsageAttribute(AttributeTargets::Class, Inherited = false)]
[ComVisibleAttribute(true)]
public ref class ComDefaultInterfaceAttribute sealed : public Attribute

JScript

public final class ComDefaultInterfaceAttribute extends Attribute

Remarks

Compilers do not necessarily respect the order in which interfaces are implemented. For example, suppose you have the following code:

interface IBase {}interface IDerived : IBase {}class MyClass : IBase, IDerived {}

The compiler emits the implemented interfaces as IDervied, IBase. The ordering of interfaces is important when using the ClassInterfaceAttribute class with [ClassInterface(ClassInterfaceType.None)] to expose an explicit interface as the default interface. Regardless of the specified ClassInterfaceType, use the ComDefaultInterfaceAttribute attribute to specify which interface should be recognized as the default.

Note that the type decorated by the ComDefaultInterfaceAttribute must actually derive from the interface specified as the default interface.

Inheritance Hierarchy

System..::.Object
System..::.Attribute
System.Runtime.InteropServices..::.ComDefaultInterfaceAttribute

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

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

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.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

Reference

ComDefaultInterfaceAttribute Members

System.Runtime.InteropServices Namespace