MemberInfo.IsDefined(Type, Boolean) MemberInfo.IsDefined(Type, Boolean) MemberInfo.IsDefined(Type, Boolean) MemberInfo.IsDefined(Type, Boolean) Method

Definition

Gibt beim Überschreiben in einer abgeleiteten Klasse an, ob ein oder mehrere Attribute des angegebenen Typs oder seiner abgeleiteten Typen auf diesen Member angewendet werden.When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member.

public:
 abstract bool IsDefined(Type ^ attributeType, bool inherit);
public abstract bool IsDefined (Type attributeType, bool inherit);
abstract member IsDefined : Type * bool -> bool
Public MustOverride Function IsDefined (attributeType As Type, inherit As Boolean) As Boolean

Parameter

attributeType
Type Type Type Type

Der Typ des zu suchenden benutzerdefinierten Attributs.The type of custom attribute to search for. Bei der Suche werden auch abgeleitete Typen berücksichtigt.The search includes derived types.

inherit
Boolean Boolean Boolean Boolean

true, um die Vererbungskette dieses Members nach den Attributen zu durchsuchen; andernfalls false.true to search this member's inheritance chain to find the attributes; otherwise, false. Dieser Parameter wird für Eigenschaften und Ereignisse ignoriert.This parameter is ignored for properties and events.

Gibt zurück

true, wenn eine oder mehrere Instanzen von attributeType oder einer seiner abgeleiteten Typen auf diesen Member angewendet wurden, andernfalls false.true if one or more instances of attributeType or any of its derived types is applied to this member; otherwise, false.

Implementiert

Beispiele

Im folgenden Beispiel wird bestimmt, ob das angegebene Attribut auf den angegebenen Member angewendet wird.The following example determines whether the specified attribute is applied to the specified member.

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 ){}
};

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++ )
      {
         // Display the attribute if it is of type MyAttribute.
         if ( myMembers[ i ]->IsDefined( MyAttribute::typeid, false ) )
         {
            array<Object^>^myAttributes = myMembers[ i ]->GetCustomAttributes( MyAttribute::typeid, false );
            Console::WriteLine( "\nThe attributes of type MyAttribute for the member {0} are: \n", myMembers[ i ] );
            for ( int j = 0; j < myAttributes->Length; j++ )

               // Display the value associated with the attribute.
               Console::WriteLine( "The value of the attribute is : \"{0}\"",
                        (safe_cast<MyAttribute^>(myAttributes[ j ]))->Name );
         }
      }
   }
   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_IsDefined
{
    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++)
            {
                // Display the attribute if it is of type MyAttribute.
                if(myMembers[i].IsDefined(typeof(MyAttribute), false))
                {
                    Object[] myAttributes = myMembers[i].GetCustomAttributes(typeof(MyAttribute), false);
                    Console.WriteLine("\nThe attributes of type MyAttribute for the member {0} are: \n",
                        myMembers[i]);
                    for(int j = 0; j < myAttributes.Length; j++)
                        // Display the value associated with the attribute.
                        Console.WriteLine("The value of the attribute is : \"{0}\"",
                            ((MyAttribute)myAttributes[j]).Name);
                }
            }
        }
        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_IsDefined

    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
                ' Display the attribute if it is of type MyAttribute.
                If myMembers(i).IsDefined(GetType(MyAttribute), False) Then
                    Dim myAttributes As [Object]() = myMembers(i).GetCustomAttributes(GetType(MyAttribute), False)
                    Console.WriteLine(ControlChars.Cr + "The attributes of type MyAttribute for the member {0} are: " + ControlChars.Cr, myMembers(i))
                    Dim j As Integer
                    For j = 0 To myAttributes.Length - 1
                        ' Display the value associated with the attribute.
                        Console.WriteLine("The value of the attribute is : ""{0}""", CType(myAttributes(j), MyAttribute).Name)
                    Next j
                End If
            Next i
        Catch e As Exception
            Console.WriteLine("An exception occurred: {0}", e.Message)
        End Try
    End Sub
End Class

Hinweise

Diese Methode ignoriert den inherit -Parameter für Eigenschaften und Ereignisse.This method ignores the inherit parameter for properties and events. Um die Vererbungs Kette nach Attributen für Eigenschaften und Ereignisse zu durchsuchen, verwenden Sie die entsprechenden Attribute.IsDefined über Ladungen der-Methode.To search the inheritance chain for attributes on properties and events, use the appropriate overloads of the Attribute.IsDefined method.

Hinweis

In der .NET Framework Version 2,0 gibt diese Methode zurück true , wenn ein Typ, eine Methode oder ein Konstruktor Sicherheits Attribute aufweist, die im neuen Metadatenformat gespeichert werden.In the .NET Framework version 2.0, this method returns true if a type, method, or constructor has security attributes stored in the new metadata format. Mit Version 2,0 kompilierte Assemblys verwenden dieses Format.Assemblies compiled with version 2.0 use this format. Dynamische Assemblys und Assemblys, die mit früheren Versionen der .NET Framework kompiliert wurden, verwenden das alte XML-FormatDynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. Siehe Ausgeben von deklarativen Sicherheits Attributen.See Emitting Declarative Security Attributes.

Gilt für: