http://www.cnblogs.com/kingdi/archive/2006/09/04/494740.html 这边参看 怎么捕获 单击最小化 按钮 事件 ...

然后 结合 NotifyMenuStrip 控件 实现你要的功能.

在FORM中加入“notifyIcon”，“contextMenuStrip”；

然后：

private void Form1_Load(object sender, EventArgs e)
        {//设置托盘控件属性
            this.notifyIcon1.ContextMenuStrip = this.contextMenuStrip1;
            this.notifyIcon1.Text = "演示创建托盘";
            this.notifyIcon1.Visible = true;
            this.notifyIcon1.Icon = new Icon("MyIcon.ico");
            this.ContextMenuStrip=this.contextMenuStrip1;
        }

然后：

编辑contextMenuStrip：“显示托盘”。“显示窗体”。“关闭程序”；编辑好后，双击每个项；

最后：

private void 显示托盘ToolStripMenuItem_Click(object sender, EventArgs e)
        {//显示托盘
            this.notifyIcon1.Visible = true;
            this.Visible = false;
        }

        private void 显示窗体ToolStripMenuItem_Click(object sender, EventArgs e)
        {//显示窗体
            this.notifyIcon1.Visible = false;
            this.Visible = true;
        }

        private void 关闭程序ToolStripMenuItem_Click(object sender, EventArgs e)
        {//关闭程序
            this.Close();
        }