事件示例

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Timers;
using System.Windows.Forms;

namespace EventLearning
{
    class Program
    {
        static void Main(string[] args)
        {
            //例一：
//            System.Timers.Timer timer = new System.Timers.Timer();//事件的拥有者
//            timer.Interval = 1000;
//            Boy boy = new Boy();//事件的响应者
//            Girl girl = new Girl();
//            timer.Elapsed += girl.Action;
//            timer.Elapsed += boy.Action;//Elapsed是事件，+=是订阅，Action是事件处理器
//            timer.Start();
//            Console.ReadKey();

            
//            //例二：事件的拥有者和响应者是不同对象
//            Form form = new Form();//事件拥有者
//
//            Controller controller = new Controller(form);//controller事件响应者，
//            form.ShowDialog();

//            //例三：事件的拥有者和响应者是相同对象
//            MyForm myForm = new MyForm();
//            myForm.Click += myForm.FormClicked;
//            myForm.ShowDialog();
//            

            //例四:事件拥有者是事件响应者的字段成员，事件响应者用自己的方法订阅自己成员的事件
            MyForm2 myForm2 = new MyForm2();
            myForm2.ShowDialog();
            
        }
    }
    
    class Controller
    {
        private Form _form;

        public Controller(Form form)
        {
            if (form!=null)
            {
                this._form = form;
                this._form.Click += this.FormClicked;//Click事件，+=订阅
            }
        }

        private void FormClicked(object sender, EventArgs e)//事件处理器
        {
            this._form.Text = DateTime.Now.ToString();
        }
    }


    class MyForm : Form
    {
        internal void FormClicked(object sender, EventArgs e)
        {
            this.Text = DateTime.Now.ToString();
        }
    }

    class  MyForm2 : Form
    {
        private TextBox _textBox;
        private Button _button1;
        private Button _button2;
        private Button _button3;
        private Button _button4;

        public MyForm2()
        {
            this._textBox = new TextBox();
            this._button1 = new Button();
            this._button2 = new Button();
            this._button3 = new Button();
            this._button4 = new Button();
            this.Controls.Add(this._button1);
            this.Controls.Add(this._button2);
            this.Controls.Add(this._button3);
            this.Controls.Add(this._button4);
            this.Controls.Add(this._textBox);
            this._button1.Click += this.ButtonClicked;
            this._button1.Text = "Say Hello";
            this._button1.Top = 100;

            this._button2.Click += this.ButtonClicked;
            this._button2.Text = "Say World";
            this._button2.Top = 130;

            this._button3.Click += new EventHandler(this.ButtonClicked);//传统挂接方式
            this._button3.Text = "ML";
            this._button3.Top = 160;

            this._button4.Click += (object sender, EventArgs e) =>
            {
                this._textBox.Text = "hahahaha";
            };//匿名函数委托形式挂接
            this._button4.Text = "hahaha";
            this._button4.Top = 190;

        }

        private void ButtonClicked(object sender, EventArgs e)//sender就是事件的发送者
        {
            if (sender==this._button1)
            {
                this._textBox.Text = "Hello";
            }
            if (sender == this._button2)
            {
                this._textBox.Text = "World";
            }
            if (sender == this._button3)
            {
                this._textBox.Text = "ML";
            }
        }
    }


    class Boy
    {
        //事件处理器
        internal void Action(object sender, ElapsedEventArgs e)
        {
            Console.WriteLine("lala~");
        }
    }


    class Girl
    {
        internal void Action(object sender, ElapsedEventArgs e)
        {
            Console.WriteLine("singing~");
        }
    }
}