AttributeTargets Enum

Definisi

Ruang nama:

System

Rakitan:

netstandard.dll, System.Runtime.dll

Sumber:

AttributeTargets.cs

Menentukan elemen aplikasi yang valid untuk menerapkan atribut.

Enumerasi ini mendukung kombinasi bitwise dari nilai yang termasuk di dalamnya.

public enum class AttributeTargets

[System.Flags]
public enum AttributeTargets

[<System.Flags>]
type AttributeTargets = 

Public Enum AttributeTargets

Warisan

Object

ValueType

Enum

AttributeTargets

Atribut

FlagsAttribute

Bidang

Nama	Nilai	Deskripsi
Assembly	1	Atribut dapat diterapkan ke rakitan.
Module	2	Atribut dapat diterapkan ke modul. Module mengacu pada file portabel yang dapat dieksekusi (.dll or.exe) dan bukan modul standar Visual Basic.
Class	4	Atribut dapat diterapkan ke kelas.
Struct	8	Atribut dapat diterapkan ke struktur; yaitu, jenis nilai.
Enum	16	Atribut dapat diterapkan ke enumerasi.
Constructor	32	Atribut dapat diterapkan ke konstruktor.
Method	64	Atribut dapat diterapkan ke metode .
Property	128	Atribut dapat diterapkan ke properti.
Field	256	Atribut dapat diterapkan ke bidang.
Event	512	Atribut dapat diterapkan ke peristiwa.
Interface	1024	Atribut dapat diterapkan ke antarmuka.
Parameter	2048	Atribut dapat diterapkan ke parameter.
Delegate	4096	Atribut dapat diterapkan ke delegasi.
ReturnValue	8192	Atribut dapat diterapkan ke nilai yang dikembalikan.
GenericParameter	16384	Atribut dapat diterapkan ke parameter generik. Saat ini, atribut ini hanya dapat diterapkan dalam C#, Microsoft bahasa perantara (MSIL), dan kode yang dipancarkan.
All	32767	Atribut dapat diterapkan ke elemen aplikasi apa pun.

Contoh

Contoh berikut mengilustrasikan penerapan atribut ke berbagai target.

Note

Visual Basic sintaks tidak mendukung penerapan atribut untuk mengetik parameter.

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

Keterangan

Kelas AttributeUsageAttribute menggunakan enumerasi ini untuk menentukan jenis elemen yang valid untuk menerapkan atribut.

AttributeTargets nilai enumerasi dapat dikombinasikan dengan operasi bitwise OR untuk mendapatkan kombinasi pilihan.

Lihat juga

• AttributeUsageAttribute