AttributeTargets Enumeration
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Specifies the application elements on which it is valid to apply an attribute.
This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
<FlagsAttribute> _
Public Enumeration AttributeTargets
[FlagsAttribute]
public enum AttributeTargets
Members
Member name | Description | |
---|---|---|
All | Attribute can be applied to any application element. | |
Assembly | Attribute can be applied to an assembly. | |
Class | Attribute can be applied to a class. | |
Constructor | Attribute can be applied to a constructor. | |
Delegate | Attribute can be applied to a delegate. | |
Enum | Attribute can be applied to an enumeration. | |
Event | Attribute can be applied to an event. | |
Field | Attribute can be applied to a field. | |
GenericParameter | Attribute can be applied to a generic parameter.
Note:
Currently, this attribute can be applied only in C#, Microsoft intermediate language (MSIL), and emitted code.
|
|
Interface | Attribute can be applied to an interface. | |
Method | Attribute can be applied to a method. | |
Module | Attribute can be applied to a module.
Note:
Module refers to a portable executable file (.dll or.exe) and not a Visual Basic standard module.
|
|
Parameter | Attribute can be applied to a parameter. | |
Property | Attribute can be applied to a property. | |
ReturnValue | Attribute can be applied to a return value. | |
Struct | Attribute can be applied to a structure; that is, a value type. |
Remarks
The AttributeUsageAttribute class uses this enumeration to specify the kind of element on which it is valid to apply an attribute.
AttributeTargets enumeration values can be combined with a bitwise OR operation to get the preferred combination.
Examples
The following example illustrates the application of attributes to various targets.
Note
Visual Basic syntax currently does not support the application of attributes to type parameters.
Module DemoModule
' This attribute is only valid on a class.
<AttributeUsage(AttributeTargets.Class)> _
Public Class ClassTargetAttribute
Inherits Attribute
End Class
' This attribute is only valid on a method.
<AttributeUsage(AttributeTargets.Method)> _
Public Class MethodTargetAttribute
Inherits Attribute
End Class
' This attribute is only valid on a constructor.
<AttributeUsage(AttributeTargets.Constructor)> _
Public Class ConstructorTargetAttribute
Inherits Attribute
End Class
' This attribute is only valid on a field.
<AttributeUsage(AttributeTargets.Field)> _
Public Class FieldTargetAttribute
Inherits Attribute
End Class
' This attribute is valid on a class or a method.
<AttributeUsage(AttributeTargets.Class Or AttributeTargets.Method)> _
Public Class ClassMethodTargetAttribute
Inherits Attribute
End Class
' This attribute is valid on any target.
<AttributeUsage(AttributeTargets.All)> _
Public Class AllTargetsAttribute
Inherits Attribute
End Class
<ClassTarget(), _
ClassMethodTarget(), _
AllTargets()> _
Public Class TestClassAttribute
<ConstructorTarget(), _
AllTargets()> _
Public Sub New()
End Sub
<MethodTarget(), _
ClassMethodTarget(), _
AllTargets()> _
Public Sub Method1()
End Sub
<FieldTarget(), _
AllTargets()> _
Public myInt As Integer
End Class
Sub Main()
End Sub
End Module
using System;
namespace AttTargsCS {
// This attribute is only valid on a class.
[AttributeUsage(AttributeTargets.Class)]
public class ClassTargetAttribute : Attribute {
}
// This attribute is only valid on a method.
[AttributeUsage(AttributeTargets.Method)]
public class MethodTargetAttribute : Attribute {
}
// This attribute is only valid on a constructor.
[AttributeUsage(AttributeTargets.Constructor)]
public class ConstructorTargetAttribute : Attribute {
}
// This attribute is only valid on a field.
[AttributeUsage(AttributeTargets.Field)]
public class FieldTargetAttribute : Attribute {
}
// This attribute is valid on a class or a method.
[AttributeUsage(AttributeTargets.Class|AttributeTargets.Method)]
public class ClassMethodTargetAttribute : Attribute {
}
// This attribute is valid on a generic type parameter.
[AttributeUsage(AttributeTargets.GenericParameter)]
public class GenericParameterTargetAttribute : Attribute {
}
// This attribute is valid on any target.
[AttributeUsage(AttributeTargets.All)]
public class AllTargetsAttribute : Attribute {
}
[ClassTarget]
[ClassMethodTarget]
[AllTargets]
public class TestClassAttribute {
[ConstructorTarget]
[AllTargets]
TestClassAttribute() {
}
[MethodTarget]
[ClassMethodTarget]
[AllTargets]
public void Method1() {
}
[FieldTarget]
[AllTargets]
public int myInt;
public void GenericMethod<
[GenericParameterTarget, AllTargets] T>(T x) {
}
static void Main(string[] args) {
}
}
}
Version Information
Windows Phone OS
Supported in: 8.1, 8.0, 7.1, 7.0
Platforms
Windows Phone