MemberInfo.IsDefined(Type, Boolean) Méthode

Définition

En cas de substitution dans une classe dérivée, indique si un ou plusieurs attributs du type spécifié ou de ses types dérivés sont appliqués à ce membre.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

Paramètres

attributeType
Type

Type de l'attribut personnalisé à rechercher.The type of custom attribute to search for. La recherche inclut les types dérivés.The search includes derived types.

inherit
Boolean

true pour rechercher la chaîne d’héritage de ce membre afin de trouver les attributs ; sinon, false.true to search this member's inheritance chain to find the attributes; otherwise, false. Ce paramètre est ignoré pour les propriétés et les événements.This parameter is ignored for properties and events.

Retours

true si une ou plusieurs instances de attributeType ou de l'un de ses types dérivés sont appliquées à ce membre ; sinon, false.true if one or more instances of attributeType or any of its derived types is applied to this member; otherwise, false.

Implémente

Exemples

L’exemple suivant détermine si l’attribut spécifié est appliqué au membre spécifié.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

Remarques

Cette méthode ignore le inherit paramètre pour les propriétés et les événements.This method ignores the inherit parameter for properties and events. Pour rechercher des attributs sur les propriétés et les événements dans la chaîne d’héritage, utilisez les surcharges appropriées de la Attribute.IsDefined méthode.To search the inheritance chain for attributes on properties and events, use the appropriate overloads of the Attribute.IsDefined method.

Notes

Dans la version .NET Framework 2,0, cette méthode retourne true si un type, une méthode ou un constructeur a des attributs de sécurité stockés dans le nouveau format de métadonnées.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. Les assemblys compilés avec la version 2,0 utilisent ce format.Assemblies compiled with version 2.0 use this format. Les assemblys dynamiques et les assemblys compilés avec des versions antérieures du .NET Framework utilisent l’ancien format XML.Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. Consultez émission d’attributs de sécurité déclaratifs.See Emitting Declarative Security Attributes.

S’applique à