AttributeTargets 列舉

定義

指定有效套用屬性的應用程式項目。Specifies the application elements on which it is valid to apply an attribute.

此列舉有 FlagsAttribute 屬性,因此其成員值可進行位元組合。

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
繼承
AttributeTargets
屬性

欄位

All 32767

屬性可以套用至任何應用程式項目。Attribute can be applied to any application element.

Assembly 1

屬性可以套用至組件。Attribute can be applied to an assembly.

Class 4

屬性可以套用至類別。Attribute can be applied to a class.

Constructor 32

屬性可以套用至建構函式。Attribute can be applied to a constructor.

Delegate 4096

屬性可以套用至委派。Attribute can be applied to a delegate.

Enum 16

屬性可以套用至列舉型別。Attribute can be applied to an enumeration.

Event 512

屬性可以套用至事件。Attribute can be applied to an event.

Field 256

屬性可以套用至欄位。Attribute can be applied to a field.

GenericParameter 16384

屬性可以套用至泛型參數。Attribute can be applied to a generic parameter. 此屬性目前僅適用於 C#、Microsoft Intermediate Language (MSIL) 和已發出的程式碼。Currently, this attribute can be applied only in C#, Microsoft intermediate language (MSIL), and emitted code.

Interface 1024

屬性可以套用至介面。Attribute can be applied to an interface.

Method 64

屬性可以套用至方法。Attribute can be applied to a method.

Module 2

屬性可以套用至模組。Attribute can be applied to a module. Module 是指可攜式執行檔 (.dll 或 .exe),且不是 Visual Basic 標準模組。Module refers to a portable executable file (.dll or.exe) and not a Visual Basic standard module.

Parameter 2048

屬性可以套用至參數。Attribute can be applied to a parameter.

Property 128

屬性 (Attibute) 可以套用至屬性 (Property)。Attribute can be applied to a property.

ReturnValue 8192

屬性可以套用至傳回值。Attribute can be applied to a return value.

Struct 8

屬性可以套用至結構,也就是實值型別 (Value Type)。Attribute can be applied to a structure; that is, a value type.

範例

下列範例說明如何將屬性應用至不同的目標。The following example illustrates the application of attributes to various targets.

注意

Visual Basic 和 Visual C++ 語法目前不支援將屬性應用至型別參數。Visual Basic and Visual C++ syntax currently do not support the application of attributes to type parameters.

using namespace System;

namespace AttTargsCS
{

   // This attribute is only valid on a class.

   [AttributeUsage(AttributeTargets::Class)]
   public ref class ClassTargetAttribute: public Attribute{};


   // This attribute is only valid on a method.

   [AttributeUsage(AttributeTargets::Method)]
   public ref class MethodTargetAttribute: public Attribute{};


   // This attribute is only valid on a constructor.

   [AttributeUsage(AttributeTargets::Constructor)]
   public ref class ConstructorTargetAttribute: public Attribute{};


   // This attribute is only valid on a field.

   [AttributeUsage(AttributeTargets::Field)]
   public ref class FieldTargetAttribute: public Attribute{};


   // This attribute is valid on a class or a method.

   [AttributeUsage(AttributeTargets::Class|AttributeTargets::Method)]
   public ref class ClassMethodTargetAttribute: public Attribute{};


   // This attribute is valid on any target.

   [AttributeUsage(AttributeTargets::All)]
   public ref class AllTargetsAttribute: public Attribute{};


   [ClassTarget]
   [ClassMethodTarget]
   [AllTargets]
   public ref class TestClassAttribute
   {
   private:

      [ConstructorTarget]
      [AllTargets]
      TestClassAttribute(){}


   public:

      [MethodTarget]
      [ClassMethodTarget]
      [AllTargets]
      void Method1(){}


      [FieldTarget]
      [AllTargets]
      int myInt;
      static void Main(){}

   };

}

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) {
        }
    }
}
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

備註

AttributeUsageAttribute類別會使用這個列舉來指定可套用屬性的元素類型。The AttributeUsageAttribute class uses this enumeration to specify the kind of element on which it is valid to apply an attribute.

AttributeTargets 列舉值可以與位 OR 運算結合,以取得慣用的組合。AttributeTargets enumeration values can be combined with a bitwise OR operation to get the preferred combination.

適用於

另請參閱