MemberInfo.IsDefined(Type, Boolean) Méthode

Définition

Espace de noms:

System.Reflection

Assemblys:

netstandard.dll, System.Runtime.dll

Source:

MemberInfo.cs

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.

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 d’attribut personnalisé à rechercher. La recherche inclut des types dérivés.

inherit

Boolean

true pour rechercher les attributs dans la chaîne d’héritage de ce membre ; sinon, false. Ce paramètre est ignoré pour les propriétés et les événements.

Retours

Boolean

true si une ou plusieurs instances de attributeType ou d’un de ses types dérivés sont appliquées à ce membre ; sinon, false.

Implémente

IsDefined(Type, Boolean)

Exemples

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

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 des propriétés et des événements. Pour rechercher dans la chaîne d’héritage des attributs sur les propriétés et les événements, utilisez les surcharges appropriées de la Attribute.IsDefined méthode.