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?
简介
目前接受的答案不工作(抛出异常),有太多的变通方法,但没有完整的代码。这显然是在浪费很多人的时间,因为这是一个很受欢迎的问题。
结合Mark Byers的回答和Karol Tyl的回答,我根据我想如何使用流程编写了完整的代码。Start方法。
使用
我用它来创建git命令的进度对话框。我是这样使用它的:
private bool Run(string fullCommand)
{
Error = "";
int timeout = 5000;
var result = ProcessNoBS.Start(
filename: @"C:\Program Files\Git\cmd\git.exe",
arguments: fullCommand,
timeoutInMs: timeout,
workingDir: @"C:\test");
if (result.hasTimedOut)
{
Error = String.Format("Timeout ({0} sec)", timeout/1000);
return false;
}
if (result.ExitCode != 0)
{
Error = (String.IsNullOrWhiteSpace(result.stderr))
? result.stdout : result.stderr;
return false;
}
return true;
}
理论上,您还可以结合stdout和stderr,但我还没有对此进行测试。
Code
public struct ProcessResult
{
public string stdout;
public string stderr;
public bool hasTimedOut;
private int? exitCode;
public ProcessResult(bool hasTimedOut = true)
{
this.hasTimedOut = hasTimedOut;
stdout = null;
stderr = null;
exitCode = null;
}
public int ExitCode
{
get
{
if (hasTimedOut)
throw new InvalidOperationException(
"There was no exit code - process has timed out.");
return (int)exitCode;
}
set
{
exitCode = value;
}
}
}
public class ProcessNoBS
{
public static ProcessResult Start(string filename, string arguments,
string workingDir = null, int timeoutInMs = 5000,
bool combineStdoutAndStderr = false)
{
using (AutoResetEvent outputWaitHandle = new AutoResetEvent(false))
using (AutoResetEvent errorWaitHandle = new AutoResetEvent(false))
{
using (var process = new Process())
{
var info = new ProcessStartInfo();
info.CreateNoWindow = true;
info.FileName = filename;
info.Arguments = arguments;
info.UseShellExecute = false;
info.RedirectStandardOutput = true;
info.RedirectStandardError = true;
if (workingDir != null)
info.WorkingDirectory = workingDir;
process.StartInfo = info;
StringBuilder stdout = new StringBuilder();
StringBuilder stderr = combineStdoutAndStderr
? stdout : new StringBuilder();
var result = new ProcessResult();
try
{
process.OutputDataReceived += (sender, e) =>
{
if (e.Data == null)
outputWaitHandle.Set();
else
stdout.AppendLine(e.Data);
};
process.ErrorDataReceived += (sender, e) =>
{
if (e.Data == null)
errorWaitHandle.Set();
else
stderr.AppendLine(e.Data);
};
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
if (process.WaitForExit(timeoutInMs))
result.ExitCode = process.ExitCode;
// else process has timed out
// but that's already default ProcessResult
result.stdout = stdout.ToString();
if (combineStdoutAndStderr)
result.stderr = null;
else
result.stderr = stderr.ToString();
return result;
}
finally
{
outputWaitHandle.WaitOne(timeoutInMs);
errorWaitHandle.WaitOne(timeoutInMs);
}
}
}
}
}
https://stackoverflow.com/a/17600012/4151626的信用归于EM0
我的应用程序的其他解决方案(包括EM0)仍然处于死锁状态,这是由于内部超时以及派生应用程序同时使用StandardOutput和standderror。以下是对我有效的方法:
Process p = new Process()
{
StartInfo = new ProcessStartInfo()
{
FileName = exe,
Arguments = args,
UseShellExecute = false,
RedirectStandardOutput = true,
RedirectStandardError = true
}
};
p.Start();
string cv_error = null;
Thread et = new Thread(() => { cv_error = p.StandardError.ReadToEnd(); });
et.Start();
string cv_out = null;
Thread ot = new Thread(() => { cv_out = p.StandardOutput.ReadToEnd(); });
ot.Start();
p.WaitForExit();
ot.Join();
et.Join();
编辑:添加初始化StartInfo代码示例
未处理的ObjectDisposedException问题发生在进程超时时。在这种情况下,条件的其他部分:
if (process.WaitForExit(timeout)
&& outputWaitHandle.WaitOne(timeout)
&& errorWaitHandle.WaitOne(timeout))
不执行。我用以下方法解决了这个问题:
using (AutoResetEvent outputWaitHandle = new AutoResetEvent(false))
using (AutoResetEvent errorWaitHandle = new AutoResetEvent(false))
{
using (Process process = new Process())
{
// preparing ProcessStartInfo
try
{
process.OutputDataReceived += (sender, e) =>
{
if (e.Data == null)
{
outputWaitHandle.Set();
}
else
{
outputBuilder.AppendLine(e.Data);
}
};
process.ErrorDataReceived += (sender, e) =>
{
if (e.Data == null)
{
errorWaitHandle.Set();
}
else
{
errorBuilder.AppendLine(e.Data);
}
};
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
if (process.WaitForExit(timeout))
{
exitCode = process.ExitCode;
}
else
{
// timed out
}
output = outputBuilder.ToString();
}
finally
{
outputWaitHandle.WaitOne(timeout);
errorWaitHandle.WaitOne(timeout);
}
}
}
我知道这是晚餐,但是,在读完这一整页后,没有一个解决方案对我来说是有效的,尽管我没有尝试Muhammad Rehan,因为代码有点难理解,尽管我猜他是在正确的轨道上。当我说它不工作时,这并不完全正确,有时它会工作得很好,我猜这与EOF标记之前的输出长度有关。
不管怎样,对我来说有效的解决方案是使用不同的线程来读取StandardOutput和StandardError并写入消息。
StreamWriter sw = null;
var queue = new ConcurrentQueue<string>();
var flushTask = new System.Timers.Timer(50);
flushTask.Elapsed += (s, e) =>
{
while (!queue.IsEmpty)
{
string line = null;
if (queue.TryDequeue(out line))
sw.WriteLine(line);
}
sw.FlushAsync();
};
flushTask.Start();
using (var process = new Process())
{
try
{
process.StartInfo.FileName = @"...";
process.StartInfo.Arguments = $"...";
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.Start();
var outputRead = Task.Run(() =>
{
while (!process.StandardOutput.EndOfStream)
{
queue.Enqueue(process.StandardOutput.ReadLine());
}
});
var errorRead = Task.Run(() =>
{
while (!process.StandardError.EndOfStream)
{
queue.Enqueue(process.StandardError.ReadLine());
}
});
var timeout = new TimeSpan(hours: 0, minutes: 10, seconds: 0);
if (Task.WaitAll(new[] { outputRead, errorRead }, timeout) &&
process.WaitForExit((int)timeout.TotalMilliseconds))
{
if (process.ExitCode != 0)
{
throw new Exception($"Failed run... blah blah");
}
}
else
{
throw new Exception($"process timed out after waiting {timeout}");
}
}
catch (Exception e)
{
throw new Exception($"Failed to succesfully run the process.....", e);
}
}
}
希望这能帮助那些认为这很难的人!
在阅读了这里所有的帖子之后,我确定了Marko avlijaovic的统一解决方案。
然而,它并没有解决我所有的问题。
在我们的环境中,我们有一个Windows服务,计划运行数百个不同的.bat .cmd .exe,…等等,这些文件积累了多年,由许多不同的人以不同的风格编写。我们无法控制程序和脚本的编写,我们只负责调度、运行和成功/失败的报告。
所以我尝试了这里所有的建议,并取得了不同程度的成功。Marko的回答几乎是完美的,但是当作为服务运行时,它并不总是捕获标准输出。我一直没搞清楚为什么不行。
我们发现在所有情况下都有效的唯一解决方案是:http://csharptest.net/319/using-the-processrunner-class/index.html