MemberInfo.IsDefined Method

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.

Parameters

• attributeType
  Type: System.Type
  The type of custom attribute to search for. The search includes derived types.

• inherit
  Type: System.Boolean
  true to search this member's inheritance chain to find the attributes; otherwise, false. This parameter is ignored for properties and events; see Remarks.

Return Value

Type: System.Boolean
true if one or more instances of attributeType or any of its derived types is applied to this member; otherwise, false.

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 'New
 Public ReadOnly Property Name() As String
 Get
 Return myName
 End Get
 End Property
End Class 'MyAttribute
' 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 'MyMethod
End Class 'MyClass1
Public Class Example
 Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
 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)
 outputBlock.Text += String.Format(ControlChars.Cr + "The attributes of type MyAttribute for the member {0} are: " + ControlChars.Cr, myMembers(i)) & vbCrLf
 Dim j As Integer
 For j = 0 To myAttributes.Length - 1
 ' Display the value associated with the attribute.
 outputBlock.Text += String.Format("The value of the attribute is : ""{0}""", CType(myAttributes(j), MyAttribute).Name) & vbCrLf
 Next j
 End If
 Next i
 Catch e As Exception
 outputBlock.Text += String.Format("An exception occurred: {0}", e.Message) & vbCrLf
 End Try
 End Sub 'Main
End Class 'MemberInfo_GetCustomAttributes_IsDefined

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 Example
{
 public static void Demo(System.Windows.Controls.TextBlock outputBlock)
 {
 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);
 outputBlock.Text += String.Format("\nThe attributes of type MyAttribute for the member {0} are: \n",
 myMembers[i]) + "\n";
 for (int j = 0; j < myAttributes.Length; j++)
 // Display the value associated with the attribute.
 outputBlock.Text += String.Format("The value of the attribute is : \"{0}\"",
 ((MyAttribute)myAttributes[j]).Name) + "\n";
 }
 }
 }
 catch (Exception e)
 {
 outputBlock.Text += String.Format("An exception occurred: {0}", e.Message) + "\n";
 }
 }
}

MemberInfo Class

System.Reflection Namespace