MemberInfo.IsDefined Method

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";
      }
   }
}