C ＃ delegate usage -- console project, which implements events through delegation

  Console project , Implement events through delegation

using System;

namespace Delegate
{
    internal class Program
    {

        #region  Commissioned cases   Enter numbers in the console , When the numbers are not equal , Two events are triggered .
        //  entrust    Case study 0.1  Enter numbers in the console , When the numbers are not equal , Two events are triggered .
        public class EventDemo
        {
            private int value;

            public delegate void SpeechHandler();// 1  Define a declaration delegate  SpeechHandler

            public event SpeechHandler ChangeSpeech;// 2  Define events according to delegates  ChangeSpeech

            #region AddSpe
            // 0.3  Methods defined in the event .  Included in the event , The specific method code for executing the behavior action of the event .
            protected virtual void AddSpe()
            {
                if(ChangeSpeech !=null)
                {
                    ChangeSpeech();
                }
                else
                {
                    Console.WriteLine(" Voice event triggers (1)!");
                }
            }
            #endregion 

            #region  Events trigger (2)  Method  GetSpe
            protected virtual void GetSpe()
            {
                if(ChangeSpeech != null)
                {
                    ChangeSpeech();
                }
                else
                {
                    Console.WriteLine(" Events trigger (2)!");
                }
            }
            #endregion

            #region  Event behavior   Method 3
            protected virtual void AddSpeech()
            {
                if (ChangeSpeech != null)
                {
                    ChangeSpeech();

                }
                else
                {
                    Console.WriteLine(" The event behavior successfully triggers execution （3）");
                }
            }

            #endregion

            #region  Set the value  GZHS The way     Where parameter values can be set   
            public EventDemo(int n)
            {
                SetValue(n);
            }

            public void SetValue(int n)
            {
                if(value != n)
                {
                    value = n;
                    AddSpe();
                    GetSpe(); 
                    // Custom events   Method 3   You must call the method in the event , To execute the event ！ Otherwise, the method in the event will not be executed .
                    AddSpeech();

                }
            }


            #endregion

            #region 

            #endregion
        }
        #endregion

        #region  Case study 2 
        // 1.  Declare a delegate （ A function pointer ）
        delegate void delegateSpeech(int a, float b);
        // delegate  return type   Delegate type name （ parameter list ）：

         2.  Create delegate object 
        //public static  delegateSpeech dT1;

        //3.  Create functions that conform to the delegate format （ The function that the pointer points to ）
        //public void Test(int a, float b)
        //{
        //    a += 100;
        //    b *= 2.0;
        //    Console.WriteLine("a:{0},b:{1}", a, b);
        //}


        #endregion

        #region 

        #endregion

        #region 

        #endregion

        static void Main(string[] args)
        {
            #region  Case study 1 
            // Instantiation of delegate class   object 
            EventDemo e = new EventDemo(0);

            Console.WriteLine(" Please enter a number ：");
            while(true)
            {
                int i= int.Parse(Console.ReadLine());//   Read the numbers and set  
                e.SetValue(i);
            }
            #endregion 
            // 4.   Assign the function name to the delegate 
            //dT1 = new delegateSpeech(Test);



        }     
    }
}

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