即使不使用 RedirectStandardError/RedirectStandardOutput，Process.WaitForExit 也会挂起

不知道这是否可以回答您的问题（我自己对此的问题多于答案），但是此代码：

    private void CleanUpAppProcess()
    {
        //...

        if(!_procCtrl.WaitForProcessToExit(TimeSpan.FromSeconds(5)))
        {
            _procCtrl.Kill();
        }
    }

在 Kill 命令之前调用 WaitForExit。您是否希望该过程在 5 秒内自行终止/由用户终止？正如 Bennie Zhitomirsky 在他的评论中指出的那样，互斥锁在它应该拥有的时候并不拥有（如果我正确理解了您想要实现的目标，如果没有，对不起）。IsAlive的实现情况如何？

无论如何，我为 ApplicationProcessControl 类写下了一些行。我只是用一些本机过程对其进行了一些测试，并且似乎有效（但是，我仍然不确定这是您想要实现的）：

    public class ApplicationProcessControl : IProcessControl
    {
        /// <summary>
        /// Process instance variable.
        /// </summary>
        private Process _proc;
        /// <summary>
        /// The thread will try to acquire the mutex for a maximum of _mutexAcquireTimeout ms.
        /// </summary>
        private const int _mutexAcquireTimeout = 5000;
        /// <summary>
        /// Global static named mutex, seen by all threads.
        /// </summary>
        private static Mutex SpawnProcessMutex = new Mutex(false, "Mutex111");
        /// <summary>
        /// The state of the process.
        /// </summary>
        public bool IsAlive
        {
            get { return !(_proc is null) && !_proc.HasExited; }
        }
        /// <summary>
        /// Spawns a new process.
        /// </summary>
        public bool Start(string arguments)
        {
            // Try to acquire the mutex for _mutexAcquireTimeout ms.
            if (!SpawnProcessMutex.WaitOne(_mutexAcquireTimeout) || IsAlive)
            {
                // Mutex is still owned (another thread got it and is trying to run the process) 
                // OR the process is already running.
                // DO NOT start a new process.
                return false;
            }

            try
            {
                // Mutex is acquired by this thread.
                // Create a new instance of the Process class.
                _proc = new Process
                {
                    EnableRaisingEvents = true,
                    StartInfo = new ProcessStartInfo("the_process_to_be_run", arguments)
                    {
                        RedirectStandardOutput = false,
                        RedirectStandardError = false
                    }
                };
                // Subscription to the ProcessExited event.
                _proc.Exited += OnProcessExited;
                // Run the process.
                var haveAnHandle = _proc.Start();

                // *******
                // TODO: The process started but we may not have an handle to it. What to do?
                // *******

                //Log.TraceInfo($"Application process with id {_proc.Id} started successfully");
                return true;
            }
            catch (Exception) // TODO: [Catch the specific exceptions here]
            {
                // The process failed to start, still we have an instance of Process with no use.
                if (!(_proc is null))
                {
                    _proc.Dispose();
                    _proc = null;
                }
                //Log.TraceInfo("Unable to start application process");
                return false;
            }
            finally 
            {
                // Release the mutex, another thread may be waiting to acquire it.
                SpawnProcessMutex.ReleaseMutex();
            }
        }
        /// <summary>
        /// Kills the process started by the Start method.
        /// </summary>
        public void Kill()
        {
            if (IsAlive) _proc.Kill();
        }
        /// <summary>
        /// Can't see a real reason to block the thread waiting synchronously for the process to
        /// exit, we are already subscribed to the Exited event.
        /// Kept here to avoid breaking the interface contract.
        /// </summary>
        public bool WaitForProcessToExit(TimeSpan timeout)
        {
            return _proc.WaitForExit((int)timeout.TotalMilliseconds);
        }
        /// <summary>
        /// Client class consumable event to know the the process actually terminated.
        /// </summary>
        public event Action ProcessExited;
        /// <summary>
        /// Process Exited event handler.
        /// </summary>
        private void OnProcessExited(object sender, EventArgs e)
        {
            // Get a reference to the actual Process object.
            var proc = sender as Process;
            if (proc is null) return;

            proc.Exited -= OnProcessExited;

            if (proc.ExitCode == 0)
            {
                // Log.TraceInfo("Application process exited gracefully");
            }
            else
            {
                // Log.DeveloperWarning("Application process exited unexpectedly with code {0}", proc.ExitCode);
                ProcessExited?.Invoke();
            }
        }
    }