检测应用程序的另一个实例是否已在运行

这可能正是你想要的。它还有一个很好的附加特性,就是将已经运行的实例向前推进。

编辑: 已更新代码以自动确定应用程序标题。

using System;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;

static void Main()
{
    if (!EnsureSingleInstance())
    {
        return;
    }

    //...
}

static bool EnsureSingleInstance()
{
    Process currentProcess = Process.GetCurrentProcess();

    var runningProcess = (from process in Process.GetProcesses()
                          where
                            process.Id != currentProcess.Id &&
                            process.ProcessName.Equals(
                              currentProcess.ProcessName,
                              StringComparison.Ordinal)
                          select process).FirstOrDefault();

    if (runningProcess != null)
    {
        ShowWindow(runningProcess.MainWindowHandle, SW_SHOWMAXIMIZED);
        SetForegroundWindow(runningProcess.MainWindowHandle);

        return false;
    }

    return true;
}

[DllImport("user32.dll", EntryPoint = "SetForegroundWindow")]
private static extern bool SetForegroundWindow(IntPtr hWnd);

[DllImport("user32.dll")]
private static extern Boolean ShowWindow(IntPtr hWnd, Int32 nCmdShow);

private const int SW_SHOWMAXIMIZED = 3;

Scott Hanselman's blog

他的例子激活了第一个实例,当第二个实例尝试时。

尝试使用信号量而不是互斥量

GetLastError() CreateMutex() ? 如果它回来了 ERROR_ALREADY_EXISTS ,则会有另一个正在运行的应用程序实例。

根据 http://msdn.microsoft.com/en-us/library/ms682411%28VS.85%29.aspx ,

如果互斥体是命名互斥体 对象在此函数之前存在 现有对象GetLastError 返回错误“\”已存在“\”, 忽略binitilowner,并且 所有权。但是,如果调用方 有限访问权限,功能 将失败,错误为\u访问被拒绝,并且 功能。

编辑:

在.Net中,使用Mutex构造函数返回createdNew标志, http://msdn.microsoft.com/en-us/library/bwe34f1k%28VS.80%29.aspx :

public Mutex (
    bool initiallyOwned,
    string name,
    out bool createdNew
)

C#: How to get the full path of running process? (杰夫的解决方案)。这样,您还可以通过路径和远程终端会话id检查其他正在运行的实例是否匹配:

    static bool EnsureSingleInstance()
    {
        Process currentProcess = Process.GetCurrentProcess();

        var wmiQueryString = "SELECT ProcessId, ExecutablePath, CommandLine FROM Win32_Process";
        using (var searcher = new ManagementObjectSearcher(wmiQueryString))
        using (var results = searcher.Get())
        {
            var query = from p in Process.GetProcesses()
                        join mo in results.Cast<ManagementObject>()
                        on p.Id equals (int)(uint)mo["ProcessId"]
                        select new
                        {
                            Process = p,
                            Path = (string)mo["ExecutablePath"],
                            CommandLine = (string)mo["CommandLine"],
                        };

            var runningProcess = (from process in query
                                  where
                                    process.Process.Id != currentProcess.Id &&
                                    process.Process.ProcessName.Equals(
                                      currentProcess.ProcessName,
                                      StringComparison.Ordinal) &&
                                      process.Path == currentProcess.MainModule.FileName &&
                                      process.Process.SessionId == currentProcess.SessionId
                                  select process).FirstOrDefault();

            return runningProcess == null;
        }
    }