C graphical tutorial (Fourth Edition)_ Chapter 13 entrustment: delegatesamplep245

using System;
// Define a delegate without return values and parameters 
delegate void PrintFunction();

class Test
{
    public void Print1()
    { Console.WriteLine("Print1---instance"); }

    public static void Print2()
    { Console.WriteLine("Print2---static"); }
}

namespace Chapter13DelegateSampleP245
{
    class Program
    {
        static void Main(string[] args)
        {
            Test t = new Test();// Create an instance of the test class 
            PrintFunction pf;// Create an empty delegate 

            pf = t.Print1;// Instantiate and initialize the delegate 

            // Add three additional methods to the delegate 
            pf += Test.Print2;
            pf += t.Print1;
            pf += Test.Print2;
            // Now?   There are four ways to delegate 
            if (null != pf)
                pf();
            else
                Console.WriteLine("Delegate is empty!");

            Console.WriteLine("Hello World!");
        }
    }
}