1.在form中添加一个NotifyIcon控件      
  
2.把87.ico这个图标放在\bin\Debug目录下   
  
using System;   
using System.Collections.Generic;   
using System.ComponentModel;   
using System.Data;   
using System.Drawing;   
using System.Text;   
using System.Windows.Forms;   
  
namespace 将程序最小化到系统托盘   
{   
    public partial class Form1 : Form   
    {   
        public Form1()   
        {   
            InitializeComponent();   
        }   
  
        private void Form1_Load(object sender, EventArgs e)   
        {   
            this.notifyIcon1 = new System.Windows.Forms.NotifyIcon(this.components);   
            notifyIcon1.Icon = new Icon("87.ico");//指定一个图标      
            notifyIcon1.Visible = false;   
            notifyIcon1.Click += new System.EventHandler(this.notifyIcon1_Click);   
            this.SizeChanged += new System.EventHandler(this.Form1_SizeChanged);      
       
  
        }   
  
        private void Form1_SizeChanged(object sender, EventArgs e)   
        {   
            if (this.WindowState == FormWindowState.Minimized)//最小化      
            {   
                this.ShowInTaskbar = false;   
                this.notifyIcon1.Visible = true;   
            }      
  
        }   
  
              private void notifyIcon1_Click(object sender, EventArgs e)   
        {   
            if (this.WindowState == FormWindowState.Minimized)   
                this.WindowState = FormWindowState.Normal;   
            this.Activate();   
            this.notifyIcon1.Visible = false;   
            this.ShowInTaskbar = true;      
  
        }   
  
    }   
}  

本文来自: IT知道网(http://www.itwis.com) 详细出处参考：http://www.itwis.com/html/net/winform/20090615/4628.html