易百教程

using System;

public class MyClass {
   [Obsolete("Don't use OldMethod, use NewMethod instead", true)]

   static void OldMethod() {
      Console.WriteLine("It is the old method");
   }

   static void NewMethod() {
      Console.WriteLine("It is the new method"); 
   }

   public static void Main() {
      OldMethod();
   }
}