确保只有一个应用程序实例 [英] Ensuring only one application instance

问题描述

可能重复：
  <一href="http://stackoverflow.com/questions/19147/what-is-the-correct-way-to-create-a-single-instance-application">What是创建一个单实例应用程序的正确方法是什么？

我有一个WinForms应用程序，它通过以下code启动一个启动画面：

I have a Winforms app, which launches a splash screen via the following code:

Hide();
        bool done = false;
        // Below is a closure which will work with outer variables.
        ThreadPool.QueueUserWorkItem(x =>
                                  {
                                      using (var splashForm = new SplashScreen())
                                      {
                                          splashForm.Show();
                                          while (!done)
                                              Application.DoEvents();
                                          splashForm.Close();
                                      }
                                  });

        Thread.Sleep(3000);
        done = true;

以上是在主窗体的codebehind从Load事件处理程序调用。

The above is in the main form's codebehind and called from the load event handler.

但是，我怎么能保证应用程序只有一个实例将加载的时间？在主窗体的Load事件处理程序，我可以检查进程列表是系统上（通过GetProcessesByName（...）），但有没有更好的方法？

However, how can I ensure that only one instance of the application will load at a time? In the load event handler of the main form, I could check if the process list is on the system (via GetProcessesByName(...)), but is there a better method?

使用.NET 3.5。

Using .NET 3.5.

推荐答案

GetProcessesByName是，如果另一个实例正在运行检查慢的方式。最快和优雅的方法是使用互斥：

GetProcessesByName is slow way of checking if another instance is running. The fastest and elegant method is using mutex:

[STAThread]
    static void Main()
    {
        bool result;
        var mutex = new System.Threading.Mutex(true, "UniqueAppId", out result);

        if (!result)
        {
            MessageBox.Show("Another instance is already running.");
            return;
        }

        Application.Run(new Form1());

        GC.KeepAlive(mutex);                // mutex shouldn't be released - important line
    }

请也记住，c您的$ C $ presented是不是最好的方法。因为它被告知的意见调用DoEvents（）在循环中是不是最好的主意。一个

Please also bear in mind that the code you presented is not the best approach. As it was advised in one of comments calling DoEvents() in a loop is not the best idea.

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