Winform 单实例运行 -- 新的呈现方式

讨论见原帖（如何操作我的程序的另一个实例(进程)）：
http://topic.csdn.net/u/20081221/01/457bb3b1-2f19-47e2-9621-cf4117ee45ce.html

using System;
using System.Threading;
using System.Windows.Forms;

static class Program
{
    public static EventWaitHandle ProgramStarted;

    [STAThread]
    static void Main()
    {
        // 尝试创建一个命名事件
        bool createNew;
        ProgramStarted = new EventWaitHandle(false, EventResetMode.AutoReset, "MyStartEvent", out createNew);

        // 如果该命名事件已经存在(存在有前一个运行实例)，则发事件通知并退出
        if (!createNew)
        {
            ProgramStarted.Set();
            return;
        }

        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}



C# code

// Form1.cs
//
using System;
using System.Windows.Forms;
using System.Threading;

public partial class Form1 : Form
{
    NotifyIcon notifyIcon1 = new NotifyIcon();

    public Form1()
    {
        //InitializeComponent();
        this.notifyIcon1.Text = "Double click me to show window";
        this.notifyIcon1.Icon = System.Drawing.SystemIcons.Information;
        this.notifyIcon1.DoubleClick += OnNotifyIconDoubleClicked;
        this.SizeChanged += OnSizeChanged;
        ThreadPool.RegisterWaitForSingleObject(Program.ProgramStarted, OnProgramStarted, null, -1, false);
    }

    // 当最小化时，放到系统托盘。
    void OnSizeChanged(object sender, EventArgs e)
    {
        if (this.WindowState == FormWindowState.Minimized)
        {
            this.notifyIcon1.Visible = true;
            this.Visible = false;
        }
    }

    // 当双击托盘图标时，恢复窗口显示
    void OnNotifyIconDoubleClicked(object sender, EventArgs e)
    {
        this.Visible = true;
        this.notifyIcon1.Visible = false;
        this.WindowState = FormWindowState.Normal;
    }

    // 当收到第二个进程的通知时，显示气球消息
    void OnProgramStarted(object state, bool timeout)
    {
        this.notifyIcon1.ShowBalloonTip(2000, "Hello", "I am here...", ToolTipIcon.Info);
    }
}