ExtensionAttribute Class

Definition

Namespace:

System.Runtime.CompilerServices

Assembly:

System.Runtime.dll

Indicates that a method is an extension method, or that a class or assembly contains extension methods.

public ref class ExtensionAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Method)]
public sealed class ExtensionAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Method)>]
type ExtensionAttribute = class
    inherit Attribute

Public NotInheritable Class ExtensionAttribute
Inherits Attribute

Inheritance

Object

Attribute

ExtensionAttribute

Attributes

AttributeUsageAttribute

Remarks

In Visual Basic, you should use this attribute to create an extension method. For more information, see Extension Methods.

In C#, you do not need to use this attribute; you should use the this modifier for the first parameter to create an extension method. The compiler automatically emits ExtensionAttribute for extension methods. For more information, see Extension Methods.

If you are writing a compiler that supports extension methods, your compiler should emit this attribute on each extension method and on each class and assembly that contains one or more extension methods.

Constructors

ExtensionAttribute()

Initializes a new instance of the ExtensionAttribute class.

Properties

TypeId

When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute)
GetHashCode()	Returns the hash code for this instance. (Inherited from Attribute)
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

See also

• Extension Methods (Visual Basic)
• Extension Methods (C# Programming Guide)