我有以下代码:

info = new System.Diagnostics.ProcessStartInfo("TheProgram.exe", String.Join(" ", args));
info.CreateNoWindow = true;
info.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
info.RedirectStandardOutput = true;
info.UseShellExecute = false;
System.Diagnostics.Process p = System.Diagnostics.Process.Start(info);
p.WaitForExit();
Console.WriteLine(p.StandardOutput.ReadToEnd()); //need the StandardOutput contents

我知道我正在启动的进程的输出大约有7MB长。在Windows控制台中运行它可以正常工作。不幸的是,从编程的角度来看,它会无限期地挂在WaitForExit上。还要注意,对于较小的输出(比如3KB),这段代码不会挂起。

ProcessStartInfo中的内部StandardOutput是否可能不能缓冲7MB?如果是,我该怎么办?如果不是,我做错了什么?


当前回答

Mark Byers的回答非常棒,但我想补充以下内容:

OutputDataReceived和ErrorDataReceived委托需要在outputWaitHandle和errorWaitHandle被释放之前被移除。如果进程在超过超时时间后继续输出数据,然后终止,则outputWaitHandle和errorWaitHandle变量将在被释放后被访问。

(仅供参考,我不得不加上这个警告作为回答,因为我不能评论他的帖子。)

其他回答

在我的情况下,我有一个错误,所以我只是徒劳地等待一个正常的输出。

我改变了顺序:

string result = process.StandardOutput.ReadToEnd();
string error = process.StandardError.ReadToEnd();

:

string error = process.StandardError.ReadToEnd();

if (string.IsNullOrEmpty(error))
    string result = process.StandardOutput.ReadToEnd();

我试图通过考虑Mark Byers, Rob, stevejay的回答,创建一个类来解决你使用异步流读取的问题。这样做,我意识到有一个与异步流程输出流读取相关的错误。

我在微软报告了这个漏洞:https://connect.microsoft.com/VisualStudio/feedback/details/3119134

简介:

You can't do that: process.BeginOutputReadLine(); process.Start(); You will receive System.InvalidOperationException : StandardOut has not been redirected or the process hasn't started yet. ============================================================================================================================ Then you have to start asynchronous output read after the process is started: process.Start(); process.BeginOutputReadLine(); Doing so, make a race condition because the output stream can receive data before you set it to asynchronous:

process.Start(); 
// Here the operating system could give the cpu to another thread.  
// For example, the newly created thread (Process) and it could start writing to the output
// immediately before next line would execute. 
// That create a race condition.
process.BeginOutputReadLine();

============================================================================================================================ Then some people could say that you just have to read the stream before you set it to asynchronous. But the same problem occurs. There will be a race condition between the synchronous read and set the stream into asynchronous mode. ============================================================================================================================ There is no way to acheive safe asynchronous read of an output stream of a process in the actual way "Process" and "ProcessStartInfo" has been designed.

对于您的情况,您最好使用其他用户建议的异步读取。但是您应该意识到,由于竞态条件,您可能会错过一些信息。

我是这样解决的:

            Process proc = new Process();
            proc.StartInfo.FileName = batchFile;
            proc.StartInfo.UseShellExecute = false;
            proc.StartInfo.CreateNoWindow = true;
            proc.StartInfo.RedirectStandardError = true;
            proc.StartInfo.RedirectStandardInput = true;
            proc.StartInfo.RedirectStandardOutput = true;
            proc.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;      
            proc.Start();
            StreamWriter streamWriter = proc.StandardInput;
            StreamReader outputReader = proc.StandardOutput;
            StreamReader errorReader = proc.StandardError;
            while (!outputReader.EndOfStream)
            {
                string text = outputReader.ReadLine();                    
                streamWriter.WriteLine(text);
            }

            while (!errorReader.EndOfStream)
            {                   
                string text = errorReader.ReadLine();
                streamWriter.WriteLine(text);
            }

            streamWriter.Close();
            proc.WaitForExit();

我重定向输入,输出和错误,并处理从输出和错误流读取。 此解决方案适用于SDK 7- 8.1,适用于Windows 7和Windows 8

罗布接了电话,帮我省了几个小时的时间。在等待之前读取输出/错误缓冲区:

// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();

这篇文章可能过时了,但我发现它通常挂起的主要原因是由于堆栈溢出的redirectStandardoutput或如果你有redirectstandderror。

由于输出数据或错误数据比较大,在不确定的时间内仍在处理,会造成挂起时间。

为了解决这个问题:

p.StartInfo.RedirectStandardoutput = False
p.StartInfo.RedirectStandarderror = False