防止.NET应用多实例运行的有效方法

public static Process GetExistProcess()  
{  
    Process currentProcess = Process.GetCurrentProcess(); // 当前程序  
    foreach (Process process in Process.GetProcessesByName(currentProcess.ProcessName))  
    {  
        if (process.Id != currentProcess.Id) // 找到其他同名进程  
        {  
            return process; // 返回已运行的进程  
        }  
    }  
    return null; // 没有其他实例  
}  

static class Program  
{  
    [STAThread]  
    static void Main()  
    {  
        Application.EnableVisualStyles();  
        Application.SetCompatibleTextRenderingDefault(false);  

        var runningProcess = GetExistProcess();  
        if (runningProcess != null) // 如果有实例运行  
        {  
            IntPtr mainWindowHandle = runningProcess.MainWindowHandle;  
            if (mainWindowHandle == IntPtr.Zero) // 窗口被隐藏  
            {  
                mainWindowHandle = FindWindow(null, "唯一程序");  
            }  
            ShowWindowAsync(mainWindowHandle, 1); // 显示窗口  
            SetForegroundWindow(mainWindowHandle); // 置于前台  
        }  
        else  
        {  
            Application.Run(new MainForm()); // 启动新实例  
        }  
    }  
}  

[DllImport("User32.dll", EntryPoint = "FindWindow")]  
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);  

[DllImport("user32.dll")]  
public static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);  

[DllImport("user32.dll ")]  
public static extern bool SetForegroundWindow(IntPtr hWnd);  

static Mutex mutex = new Mutex(true, "UniqueAppName", out bool createdNew);  
    if (!createdNew)  
    {  
    // 已经有实例运行  
    return;  
    }