NotifyIcon

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WinFormNotify
{
    public partial class FormNotify : Form
    {
        #region AnimateWindow
        [DllImport("user32.dll", EntryPoint = "AnimateWindow")]
        private static extern bool AnimateWindow(IntPtr handle, int ms, int flags);
        #endregion

        #region
        private NotifyIcon notifyInfo;
        #endregion

        public FormNotify()
        {
            #region
            InitializeComponent();
            // 上下文菜单
            ContextMenuStrip contextMenu = new ContextMenuStrip();
            contextMenu.Items.Add("显示/隐藏(&V)");
            contextMenu.Items.Add("系统退出(&X)");
            contextMenu.ItemClicked += new ToolStripItemClickedEventHandler(contextMenu_ItemClicked);
            // 系统托盘
            notifyInfo = new NotifyIcon();
            notifyInfo.Visible = true;
            notifyInfo.Icon = System.Drawing.Icon.ExtractAssociatedIcon(Application.ExecutablePath); // 启动程序图标。
            notifyInfo.Text = AppDomain.CurrentDomain.FriendlyName; // 启动程序名称。
            notifyInfo.ContextMenuStrip = contextMenu;
            notifyInfo.DoubleClick += new EventHandler(notifyInfo_DoubleClick);
            // 当前窗体
            this.ContextMenuStrip = contextMenu;
            this.StartPosition = FormStartPosition.CenterScreen;
            #endregion
        }

        #region FormVisible
        private void notifyInfo_DoubleClick(object sender, EventArgs e)
        {
            this.Visible = !this.Visible;
        }

        protected override void OnVisibleChanged(EventArgs e)
        {
            base.OnVisibleChanged(e);
            if (this.Visible)
            {
                AnimateWindow(this.Handle, 1000, 0x20010); // 居中逐渐显示。
                this.Activate(); // 激活窗体并给予它焦点。
            }
            else
            {
                AnimateWindow(this.Handle, 1000, 0x10010); // 居中逐渐隐藏。
                notifyInfo.ShowBalloonTip(10, notifyInfo.Text, "    在系统托盘中运行", ToolTipIcon.Info);
            }
        }
        #endregion

        #region 上下文菜单事件
        private void contextMenu_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {
            switch (e.ClickedItem.Owner.Items.IndexOf(e.ClickedItem))
            {
                case 0:
                    this.Visible = !this.Visible;
                    break;
                case 1:
                    if (MessageBox.Show(this, "您真的要退出系统吗？", "系统询问", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK)
                        Application.Exit();
                    break;
            }
        }
        #endregion

        #region FormClosing
        protected override void OnFormClosing(FormClosingEventArgs e)
        {
            base.OnFormClosing(e);
            this.Visible = false;
            switch (e.CloseReason)
            {
                case CloseReason.ApplicationExitCall:
                case CloseReason.TaskManagerClosing:
                    notifyInfo.Dispose();
                    break;
                case CloseReason.UserClosing:
                    e.Cancel = true;
                    break;
            }
        }
        #endregion
    }
}