MemberInfo.GetCustomAttributes 方法

参考

定义

命名空间:: System.Reflection

程序集:: System.Runtime.dll

程序集:: netstandard.dll

程序集:: mscorlib.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

在派生类中重写时，返回应用于此成员的自定义属性。

重载

GetCustomAttributes(Boolean)	在派生类中重写时，返回应用于此成员的所有自定义属性的数组。
GetCustomAttributes(Type, Boolean)	在派生类中重写时，返回应用于此成员并由 Type 标识的自定义属性的数组。

GetCustomAttributes(Boolean)

在派生类中重写时，返回应用于此成员的所有自定义属性的数组。

public:
 abstract cli::array <System::Object ^> ^ GetCustomAttributes(bool inherit);

public abstract object[] GetCustomAttributes (bool inherit);

abstract member GetCustomAttributes : bool -> obj[]

Public MustOverride Function GetCustomAttributes (inherit As Boolean) As Object()

参数

inherit: Boolean

如果要搜索此成员的继承链以查找属性，则为 true；否则为 false。会忽略属性和事件的此参数。

Object[]

一个包含应用于此成员的所有自定义属性的数组，或者在未定义任何特性时为包含零个元素的数组。

实现

GetCustomAttributes(Boolean) GetCustomAttributes(Boolean)

例外

InvalidOperationException

此成员属于加载到仅反射的上下文的类型。请参阅如何：将程序集加载到仅反射上下文中。

TypeLoadException

无法加载自定义属性类型。

示例

下面的示例定义一个自定义属性，并且将该属性与关联，并运行时检索该属性 MyClass.MyMethod 并显示结果。

using namespace System;
using namespace System::Reflection;

// Define a custom attribute with one named parameter.

[AttributeUsage(AttributeTargets::All)]
public ref class MyAttribute: public Attribute
{
private:
   String^ myName;

public:
   MyAttribute( String^ name )
   {
      myName = name;
   }

   property String^ Name 
   {
      String^ get()
      {
         return myName;
      }
   }
};

// Define a class that has the custom attribute associated with one of its members.
public ref class MyClass1
{
public:

   [MyAttribute("This is an example attribute.")]
   void MyMethod( int i )
   {
      return;
   }
};

int main()
{
   try
   {
      // Get the type of MyClass1.
      Type^ myType = MyClass1::typeid;

      // Get the members associated with MyClass1.
      array<MemberInfo^>^myMembers = myType->GetMembers();

      // Display the attributes for each of the members of MyClass1.
      for ( int i = 0; i < myMembers->Length; i++ )
      {
         array<Object^>^myAttributes = myMembers[ i ]->GetCustomAttributes( true );
         if ( myAttributes->Length > 0 )
         {
            Console::WriteLine( "\nThe attributes for the member {0} are: \n", myMembers[ i ] );
            for ( int j = 0; j < myAttributes->Length; j++ )
               Console::WriteLine( "The type of the attribute is {0}.", myAttributes[ j ] );
         }
      }
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "An exception occurred: {0}", e->Message );
   }
}

using System;
using System.Reflection;

// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets.All)]
public class MyAttribute : Attribute
{
    private string myName;
    public MyAttribute(string name)
    {
        myName = name;
    }
    public string Name
    {
        get
        {
            return myName;
        }
    }
}

// Define a class that has the custom attribute associated with one of its members.
public class MyClass1
{
    [MyAttribute("This is an example attribute.")]
    public void MyMethod(int i)
    {
        return;
    }
}

public class MemberInfo_GetCustomAttributes
{
    public static void Main()
    {
        try
        {
            // Get the type of MyClass1.
            Type myType = typeof(MyClass1);
            // Get the members associated with MyClass1.
            MemberInfo[] myMembers = myType.GetMembers();

            // Display the attributes for each of the members of MyClass1.
            for(int i = 0; i < myMembers.Length; i++)
            {
                Object[] myAttributes = myMembers[i].GetCustomAttributes(true);
                if(myAttributes.Length > 0)
                {
                    Console.WriteLine("\nThe attributes for the member {0} are: \n", myMembers[i]);
                    for(int j = 0; j < myAttributes.Length; j++)
                        Console.WriteLine("The type of the attribute is {0}.", myAttributes[j]);
                }
            }
        }
        catch(Exception e)
        {
            Console.WriteLine("An exception occurred: {0}", e.Message);
        }
    }
}

Imports System.Reflection

' Define a custom attribute with one named parameter.
<AttributeUsage(AttributeTargets.All)> Public Class MyAttribute
    Inherits Attribute
    Private myName As String

    Public Sub New(ByVal name As String)
        myName = name
    End Sub

    Public ReadOnly Property Name() As String
        Get
            Return myName
        End Get
    End Property
End Class

' Define a class that has the custom attribute associated with one of its members.
Public Class MyClass1

    <MyAttribute("This is an example attribute.")> Public Sub MyMethod(ByVal i As Integer)
        Return
    End Sub
End Class


Public Class MemberInfo_GetCustomAttributes

    Public Shared Sub Main()
        Try
            ' Get the type of MyClass1.
            Dim myType As Type = GetType(MyClass1)
            ' Get the members associated with MyClass1.
            Dim myMembers As MemberInfo() = myType.GetMembers()

            ' Display the attributes for each of the members of MyClass1.
            Dim i As Integer
            For i = 0 To myMembers.Length - 1
                Dim myAttributes As [Object]() = myMembers(i).GetCustomAttributes(False)
                If myAttributes.Length > 0 Then
                    Console.WriteLine("The attributes for the member {0} are: ", myMembers(i))
                    Dim j As Integer
                    For j = 0 To myAttributes.Length - 1
                        Console.WriteLine("The type of the attribute is: {0}", myAttributes(j))
                    Next j
                End If
            Next i
        Catch e As Exception
            Console.WriteLine("An exception occurred: {0}.", e.Message)
        End Try
    End Sub
End Class

注解

此方法忽略 inherit 属性和事件的参数。若要在继承链中搜索属性和事件的属性，请使用方法的适当 Attribute.GetCustomAttributes 重载。

备注

在 .NET Framework 2.0 版中，如果方法、构造函数和类型以新的元数据格式存储，此方法将返回这些特性的安全属性。使用版本 2.0 编译的程序集使用此格式。使用早期版本的程序集编译的动态程序集.NET Framework使用旧的 XML 格式。请参阅发出声明性安全属性。

另请参阅

适用于

GetCustomAttributes(Type, Boolean)

在派生类中重写时，返回应用于此成员并由 Type 标识的自定义属性的数组。

public:
 abstract cli::array <System::Object ^> ^ GetCustomAttributes(Type ^ attributeType, bool inherit);

public abstract object[] GetCustomAttributes (Type attributeType, bool inherit);

abstract member GetCustomAttributes : Type * bool -> obj[]

Public MustOverride Function GetCustomAttributes (attributeType As Type, inherit As Boolean) As Object()

参数

attributeType: Type

要搜索的属性的类型。仅返回可分配给此类型的属性。

inherit: Boolean

如果要搜索此成员的继承链以查找属性，则为 true；否则为 false。会忽略属性和事件的此参数。

Object[]

应用于此成员的自定义属性的数组，如果未应用可分配给 attributeType 的属性，则为含零元素的数组。

实现

GetCustomAttributes(Type, Boolean) GetCustomAttributes(Type, Boolean)

例外

TypeLoadException

无法加载自定义属性类型。

ArgumentNullException

如果 attributeType 为 null。

InvalidOperationException

此成员属于加载到仅反射的上下文的类型。请参阅如何：将程序集加载到仅反射上下文中。

示例

以下示例定义一个名为的类，该类具有两个非继承成员：名为的线程静态字段和一个名为的不符合 BaseClass total CLS 的方法 MethodA 。名为的 DerivedClass 类继承自 BaseClass 并重写其 MethodA 方法。请注意，没有属性应用于的成员 DerivedClass 。该示例会访问的成员，以确定是否应用了或 DerivedClass CLSCompliantAttribute ThreadStaticAttribute 属性。因为 inherit true 是，所以方法在的继承层次结构中 DerivedClass 搜索指定的属性。如示例的输出所示，字段使用属性进行修饰，方法 total ThreadStaticAttribute 使用 MethodA 属性 CLSCompliantAttribute 进行修饰。

using System;

public class BaseClass
{
   [ThreadStatic] public int total;

   [CLSCompliant(false)] public virtual uint MethodA()
   {
      return (uint) 100;
   }
}

public class DerivedClass : BaseClass
{
   public override uint MethodA()
   {
      total++;
      return 200;
   }
}

public class Example
{
   public static void Main()
   {
      Type t = typeof(DerivedClass);
      Console.WriteLine("Members of {0}:", t.FullName);
      foreach (var m in t.GetMembers())
      {
         bool hasAttribute = false;
         Console.Write("   {0}: ", m.Name);
         if (m.GetCustomAttributes(typeof(CLSCompliantAttribute), true).Length > 0) {
            Console.Write("CLSCompliant");
            hasAttribute = true;
         }
         if (m.GetCustomAttributes(typeof(ThreadStaticAttribute), true).Length > 0) {
            Console.Write("ThreadStatic");
            hasAttribute = true;
         }
         if (! hasAttribute)
            Console.Write("No attributes");

         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//       Members of DerivedClass:
//          MethodA: CLSCompliant
//          ToString: No attributes
//          Equals: No attributes
//          GetHashCode: No attributes
//          typeof: No attributes
//          .ctor: No attributes
//          total: ThreadStatic

Public Class BaseClass
   <ThreadStatic> Public total As Integer
   
   <CLSCompliant(False)> Public Overridable Function MethodA() As UInt32
      Return CUInt(100)
   End Function
End Class

Public Class DerivedClass : Inherits BaseClass
   Public Overrides Function MethodA() As UInt32
      total += 1
      Return 200
   End Function
End Class

Module Example
   Public Sub Main()
      Dim t As Type = GetType(DerivedClass)
      Console.WriteLine("Members of {0}:", t.FullName)
      For Each m In t.GetMembers()
         Dim hasAttribute As Boolean = False
         Console.Write("   {0}: ", m.Name)
         If m.GetCustomAttributes(GetType(CLSCompliantAttribute), True).Length > 0 Then
            Console.Write("CLSCompliant")
            hasAttribute = True
         End If
         If m.GetCustomAttributes(GetType(ThreadStaticAttribute), True).Length > 0 Then
            Console.Write("ThreadStatic")
            hasAttribute = True
         End If
         If Not hasAttribute Then
            Console.Write("No attributes")
         End If
         Console.WriteLine()
      Next
   End Sub
End Module
' The example displays the following output:
'       Members of DerivedClass:
'          MethodA: CLSCompliant
'          ToString: No attributes
'          Equals: No attributes
'          GetHashCode: No attributes
'          GetType: No attributes
'          .ctor: No attributes
'          total: ThreadStatic

注解

此方法忽略 inherit 属性和事件的参数。若要在继承链中搜索属性和事件的属性，请使用方法的适当 Attribute.GetCustomAttributes 重载。

备注

在 .NET Framework 2.0 版中，如果属性以新的元数据格式存储，此方法将返回方法、构造函数和类型的安全属性。使用版本 2.0 编译的程序集使用此格式。使用早期版本的程序集编译的动态程序集.NET Framework使用旧的 XML 格式。请参阅发出声明性安全属性。

适用于

MemberInfo.GetCustomAttributes 方法

定义

重载

GetCustomAttributes(Boolean)

参数

返回

实现

例外

示例

注解

另请参阅

适用于

GetCustomAttributes(Type, Boolean)

参数

返回

实现

例外

示例

注解

适用于

其他资源