2

我有一个 ChildProcessMonitor 类，它启动我的进程，报告接收到的数据并在进程退出时重新启动进程。我的问题是，一旦进程退出并再次调用 Start ，就不再报告输出。

using System;
using System.Diagnostics;
using System.IO;
using System.Threading;

namespace WcfClient
{
    /// <summary>
    /// Can be used to launch and monitor (restart on crash) the child process.
    /// </summary>
    public class ChildProcessMonitor
    {
        private Process _process;

        /// <summary>
        /// Starts and monitors the child process.
        /// </summary>
        /// <param name="fullProcessPath">The full executable process path.</param>
        public void StartAndMonitor(string fullProcessPath)
        {
            StartAndMonitor(fullProcessPath, null);
        }

        /// <summary>
        /// Starts and monitors the child process.
        /// </summary>
        /// <param name="fullProcessPath">The full executable process path.</param>
        /// <param name="arguments">The process arguments.</param>
        public void StartAndMonitor(string fullProcessPath, string arguments)
        {
            ProcessStartInfo processStartInfo = new ProcessStartInfo
            {
                CreateNoWindow = true,
                FileName = fullProcessPath,
                WorkingDirectory = Path.GetDirectoryName(fullProcessPath) ?? string.Empty,
                UseShellExecute = false,
                RedirectStandardOutput = true,
                RedirectStandardError = true
            };

            processStartInfo.Arguments = arguments;             

            _process = new Process { StartInfo = processStartInfo, EnableRaisingEvents = true };
            _process.OutputDataReceived += OnOutputDataReceived;
            _process.ErrorDataReceived += OnErrorDataReceived;
            _process.Start();
            _process.BeginOutputReadLine();
            _process.BeginErrorReadLine();
            _process.Exited += OnProcessExited;
        }

        /// <summary>
        /// Called when process exits.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
        private void OnProcessExited(object sender, EventArgs e)
        {
            if (_process != null)
            {
                Thread.Sleep(2000);                 
                _process.Start();                       
            }
        }

        /// <summary>
        /// The ErrorDataReceived event indicates that the associated process has written to its redirected StandardError stream.
        /// </summary>
        public DataReceivedEventHandler ErrorDataReceived;

        /// <summary>
        /// Called when error data received.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="System.Diagnostics.DataReceivedEventArgs"/> instance containing the event data.</param>
        private void OnErrorDataReceived(object sender, DataReceivedEventArgs e)
        {
            Trace.WriteLine("Error data.");
            if (ErrorDataReceived != null)
            {
                ErrorDataReceived(sender, e);
            }
        }

        /// <summary>
        /// The OutputDataReceived event indicates that the associated Process has written to its redirected StandardOutput stream.
        /// </summary>
        public DataReceivedEventHandler OutputDataReceived;

        /// <summary>
        /// Called when output data received.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="System.Diagnostics.DataReceivedEventArgs"/> instance containing the event data.</param>
        private void OnOutputDataReceived(object sender, DataReceivedEventArgs e)
        {
            Trace.WriteLine("Output data.");
            if (OutputDataReceived != null)
            {
                OutputDataReceived(sender, e);
            }
        }

    }

}
4

2 回答 2

5

尝试使用：

private void OnProcessExited(object sender, EventArgs e)
{
  if (_process != null)
  {
    Thread.Sleep(2000);
    _process.CancelOutputRead();
    _process.CancelErrorRead();
    _process.Start();
    _process.BeginOutputReadLine();
    _process.BeginErrorReadLine();

  }
}

ps

简短描述：OutputRead 和 ErrorRead 因进程重新启动而关闭。

来自反射的代码的详细描述：

public void BeginOutputRead()
{
  [..]
  if (this.output == null)
  {
    [..]                    
    this.output = new AsyncStreamReader(this, baseStream, new UserCallBack(this.OutputReadNotifyUser), this.standardOutput.CurrentEncoding);
  }
}

public void Start()
{   
    this.Close();
    [..]
}

public void Close()
{   
    [..]
    this.output = null;
    this.error = null;
    [..]
}
于 2012-06-06T20:06:05.640 回答
3

选项 1 - 无效

我会尝试这个编辑。它将刷新对象上的事件处理程序。

private void OnProcessExited(object sender, EventArgs e)
        {
            if (_process != null)
            {
                Thread.Sleep(2000); 
                _process.OutputDataReceived -= OnOutputDataReceived;
                _process.ErrorDataReceived -= OnErrorDataReceived;
                _process.OutputDataReceived += OnOutputDataReceived;
                _process.ErrorDataReceived += OnErrorDataReceived;                
                _process.Start();                       
            }
        }

选项 2

我的下一个想法是建议对设计稍作改动。将 ProcessStartInfo 存储在类中，然后当退出而不是在现有进程上调用 Start 时，将其释放并使用 ProcessStartInfo 对象创建一个新进程。

选项 3

在阅读了关于流程类的 MSDN 之后，我相信这个摘录解释了这个问题

ErrorDataReceived 事件表明相关进程已写入其重定向的 StandardError 流。

该事件仅在 StandardError 的异步读取操作期间发生。要启动异步读取操作，您必须重定向 Process 的 StandardError 流，将您的事件处理程序添加到 ErrorDataReceived 事件，然后调用 BeginErrorReadLine。此后，每次进程向重定向的 StandardError 流写入一行时，ErrorDataReceived 事件都会发出信号，直到进程退出或调用 CancelErrorRead。

MSDN 链接

因此，您只需要在退出处理代码中执行此操作

    _process.Start();
    _process.BeginOutputReadLine();
    _process.BeginErrorReadLine();
于 2012-06-06T18:26:37.703 回答