C#实现窗口最小化到系统托盘

先添加notifyicon控件notifyIcon1 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace notifyIconShow
{
    public partial class ColdJoke : Form
    {
        #region
        //创建NotifyIcon对象 
        NotifyIcon notifyicon = new NotifyIcon();
        //创建托盘图标对象 
        Icon ico = new Icon("snow.ico");
        //创建托盘菜单对象 
        ContextMenu notifyContextMenu = new ContextMenu();
        #endregion

        public ColdJoke()
        {
            InitializeComponent();
        }

        #region 托盘提示
        private void Form1_Load(object sender, EventArgs e)
        {
            //设置鼠标放在托盘图标上面的文字 
            this.notifyIcon1.Text = "笑话";
        }
        #endregion

        #region 隐藏任务栏图标、显示托盘图标
        private void Form1_SizeChanged(object sender, EventArgs e)
        {
            //判断是否选择的是最小化按钮 
            if (WindowState == FormWindowState.Minimized)
            {
                //托盘显示图标等于托盘图标对象 
                //注意notifyIcon1是控件的名字而不是对象的名字 
                notifyIcon1.Icon = ico;
                //隐藏任务栏区图标 
                this.ShowInTaskbar = false;
                //图标显示在托盘区 
                notifyicon.Visible = true;
            }
        }
        #endregion

        #region 还原窗体
        private void notifyIcon1_DoubleClick(object sender, EventArgs e)
        {
            //判断是否已经最小化于托盘 
            if (WindowState == FormWindowState.Minimized)
            {
                //还原窗体显示 
                WindowState = FormWindowState.Normal;
                //激活窗体并给予它焦点 
                this.Activate();
                //任务栏区显示图标 
                this.ShowInTaskbar = true;
                //托盘区图标隐藏 
                notifyicon.Visible = false;
            }
        }
        #endregion
    }

}