1.在form中添加一个NotifyIcon控件　

2.把1.ico这个图标放在binDebug目录下　

先看看效果图：

3.代码的实现　

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

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            this.Text = "实现最小托盘";
            this.notifyIcon1.Icon = new Icon("1.ico");//设置当前图标
        }

        private void button1_Click(object sender, EventArgs e)
        {

            WindowState = FormWindowState.Minimized;//最小化时隐藏窗体
            //this.Visible = false; //是否显示该控件
            this.notifyIcon1.Visible = true;     //图标在任务栏区域中可见
            this.notifyIcon1.ShowBalloonTip(300, "哈哈", "窗体成功隐藏了", ToolTipIcon.Info); //设置气球状工具提示显示的时间为10秒
            this.ShowInTaskbar =false;//windows任务栏中不显示窗体
        }

        private void button2_Click(object sender, EventArgs e)
        {
            WindowState = FormWindowState.Maximized; //窗体{zd0}化
        }

        private void button3_Click(object sender, EventArgs e)
        {
            WindowState = FormWindowState.Normal; //窗体常规
        }

        private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)//判断是否窗体最小化
            {
                this.WindowState = FormWindowState.Normal;
            }

            this.Activate();//xx窗体
            this.notifyIcon1.Visible = false;//在任务栏区域中不显示图标
            this.ShowInTaskbar = true;　//窗体在任务栏区域中可见
        }

    }
}