AttributeTargets 枚举

定义

命名空间:
System
程序集:
mscorlib.dll, System.Runtime.dll
程序集:
netstandard.dll, System.Runtime.dll
程序集:
System.Runtime.dll
程序集:
mscorlib.dll
程序集:
netstandard.dll
Source:
AttributeTargets.cs
Source:
AttributeTargets.cs
Source:
Lazy.cs

指定应用属性的有效应用程序元素。

此枚举支持其成员值的按位组合。

public enum class AttributeTargets
[System.Flags]
public enum AttributeTargets
[System.Flags]
[System.Serializable]
public enum AttributeTargets
[System.Flags]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum AttributeTargets
[<System.Flags>]
type AttributeTargets = 
[<System.Flags>]
[<System.Serializable>]
type AttributeTargets = 
[<System.Flags>]
[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type AttributeTargets = 
Public Enum AttributeTargets
继承
Object
ValueType
Enum
AttributeTargets
属性
FlagsAttribute SerializableAttribute ComVisibleAttribute

字段

名称 值 说明
Assembly 1

特性可以应用于程序集。
Module 2

属性可以应用于模块。 Module是指可移植可执行文件（.dll or.exe），而不是Visual Basic标准模块。
Class 4

属性可以应用于类。
Struct 8

特性可以应用于结构;即值类型。
Enum 16

属性可以应用于枚举。
Constructor 32

特性可以应用于构造函数。
Method 64

属性可以应用于方法。
Property 128

属性可以应用于属性。
Field 256

属性可以应用于字段。
Event 512

属性可以应用于事件。
Interface 1024

属性可以应用于接口。
Parameter 2048

特性可以应用于参数。
Delegate 4096

属性可以应用于委托。
ReturnValue 8192

属性可以应用于返回值。
GenericParameter 16384

特性可以应用于泛型参数。 目前，此属性只能在 C# 中应用，Microsoft中间语言 （MSIL），并发出代码。
All 32767

属性可以应用于任何应用程序元素。

示例

以下示例演示了将属性应用于各种目标。

注释

Visual Basic语法不支持将属性应用于类型参数。

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) {
        }
    }
}

open System

// This attribute is only valid on a class.
[<AttributeUsage(AttributeTargets.Class)>]
type ClassTargetAttribute() =
    inherit Attribute()

// This attribute is only valid on a method.
[<AttributeUsage(AttributeTargets.Method)>]
type MethodTargetAttribute() =
    inherit Attribute()

// This attribute is only valid on a constructor.
[<AttributeUsage(AttributeTargets.Constructor)>]
type ConstructorTargetAttribute() =
    inherit Attribute()

// This attribute is only valid on a field.
[<AttributeUsage(AttributeTargets.Field)>]
type FieldTargetAttribute() =
    inherit Attribute()

// This attribute is valid on a class or a method.
[<AttributeUsage(AttributeTargets.Class ||| AttributeTargets.Method)>]
type ClassMethodTargetAttribute() =
    inherit Attribute()

// This attribute is valid on a generic type parameter.
[<AttributeUsage(AttributeTargets.GenericParameter)>]
type GenericParameterTargetAttribute() =
    inherit Attribute()

// This attribute is valid on any target.
[<AttributeUsage(AttributeTargets.All)>]
type AllTargetsAttribute() =
    inherit Attribute()

[<ClassTarget>]
[<ClassMethodTarget>]
[<AllTargets>]
type TestClassAttribute [<ConstructorTarget>] [<AllTargets>] () =
    [<FieldTarget>]
    [<AllTargets>]
    let myInt = 0

    [<MethodTarget>]
    [<ClassMethodTarget>]
    [<AllTargets>]
    member _.Method1() = ()

    member _.GenericMethod<[<GenericParameterTarget; AllTargets>] 'T>(x: 'T) = ()

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

注解

该 AttributeUsageAttribute 类使用此枚举来指定应用属性的有效元素类型。

AttributeTargets 枚举值可以与按位 OR 操作组合，以获取首选组合。

适用于

另请参阅