C＃：重定向控制台应用程序的输出：如何刷新输出？ [英] C# : Redirect console application output : How to flush the output?
问题描述
我产卵外部控制台应用程序，并使用异步输出重定向。
<一href=\"http://stackoverflow.com/questions/442680/best-way-to-interact-with-command-line-application\">as这表明在post
I am spawning external console application and use async output redirect.
as shown in this SO post
我的问题是，似乎产生的进程，需要产生一定量的输出之前，我在 OutputDataReceived 事件通知。
My problem is it seems that the spawned process needs to produce certain amount of output before I get the OutputDataReceived event notification.
我想尽快收到 OutputDataReceived 事件。
我有一个最基本的应用重定向，这里有一些意见：
1.当我打电话一个简单的'，而（真）打印（X）;控制台应用程序（C＃）我立即收到输出事件。
2.当我打电话三维第三方的应用，我试图总结在命令行中的 我看行由行输出。
3.当我打电话从我的裸骨包装，3D第三方的应用（参见图1） - 输出进来块（约一页面大小）。
I have a bare-bones redirecting application, and here are some observations:
1. When I call a simple 'while(true) print("X");' console application (C#) I receive output event immediately.
2. When I call a 3d party app I am trying to wrap from the command line I see the line-by-line output.
3. When I call that 3d party app from my bare-bone wrapper (see 1) - the output comes in chunks (about one page size).
这是内部应用程序，会发生什么？
What happens inside that app?
FYI：有问题的应用程序是一个USBee DX数据Exctarctor（异步总线）V1.0
FYI: The app in question is a "USBee DX Data Exctarctor (Async bus) v1.0".
推荐答案
我做了一些更多的研究，并有一个修复程序微软Process类。但正如我最后的答案是没有理由删除了，我不得不创建一个新的。
I did some more research and have a fix to microsofts Process class. But as my last answer was deleted without a reason, I have had to create a new one.
所以要这个例子...
So take this example...
创建一个Windows应用程序，并坚持在主窗体上丰富的文本框，然后将它添加到窗体加载...
Create a windows app and stick a rich textbox on the main form, then add this to the form load...
Process p = new Process()
{
StartInfo = new ProcessStartInfo()
{
FileName = "cmd.exe",
CreateNoWindow = true,
UseShellExecute = false,
ErrorDialog = false,
RedirectStandardInput = true,
RedirectStandardOutput = true,
RedirectStandardError = true,
},
EnableRaisingEvents = true,
SynchronizingObject = this
};
p.OutputDataReceived += (s, ea) => this.richTextBox1.AppendText(ea.Data);
p.Start();
p.BeginOutputReadLine();
这将输出这样的事情...
This will output something like this...
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
该OutputDataReceived事件不会解雇的最后一行。一些ILSpying后看来，这是故意的，因为最后一行不以CRLF结束，它假定有正在添加更多的，并追加到下一个事件的开始。
The OutputDataReceived event is not fired for the last line. After some ILSpying it appears that this is deliberate because the last line does not end with a crlf, it assumes there is more comming and appends it to the start of the next event.
要解决这个问题，我已经写了Process类的包装和一些必要的内部类与它取出来，让这一切工作整齐。这里是FixedProcess类...
To correct this, I have written a wrapper for the Process class and taken some of the required internal classes out with it so that it all works neatly. Here is the FixedProcess class...
using System;
using System.Collections;
using System.IO;
using System.Text;
using System.Threading;
namespace System.Diagnostics
{
internal delegate void UserCallBack(string data);
public delegate void DataReceivedEventHandler(object sender, DataReceivedEventArgs e);
public class FixedProcess : Process
{
internal AsyncStreamReader output;
internal AsyncStreamReader error;
public event DataReceivedEventHandler OutputDataReceived;
public event DataReceivedEventHandler ErrorDataReceived;
public new void BeginOutputReadLine()
{
Stream baseStream = StandardOutput.BaseStream;
this.output = new AsyncStreamReader(this, baseStream, new UserCallBack(this.FixedOutputReadNotifyUser), StandardOutput.CurrentEncoding);
this.output.BeginReadLine();
}
public void BeginErrorReadLine()
{
Stream baseStream = StandardError.BaseStream;
this.error = new AsyncStreamReader(this, baseStream, new UserCallBack(this.FixedErrorReadNotifyUser), StandardError.CurrentEncoding);
this.error.BeginReadLine();
}
internal void FixedOutputReadNotifyUser(string data)
{
DataReceivedEventHandler outputDataReceived = this.OutputDataReceived;
if (outputDataReceived != null)
{
DataReceivedEventArgs dataReceivedEventArgs = new DataReceivedEventArgs(data);
if (this.SynchronizingObject != null && this.SynchronizingObject.InvokeRequired)
{
this.SynchronizingObject.Invoke(outputDataReceived, new object[]
{
this,
dataReceivedEventArgs
});
return;
}
outputDataReceived(this, dataReceivedEventArgs);
}
}
internal void FixedErrorReadNotifyUser(string data)
{
DataReceivedEventHandler errorDataReceived = this.ErrorDataReceived;
if (errorDataReceived != null)
{
DataReceivedEventArgs dataReceivedEventArgs = new DataReceivedEventArgs(data);
if (this.SynchronizingObject != null && this.SynchronizingObject.InvokeRequired)
{
this.SynchronizingObject.Invoke(errorDataReceived, new object[]
{
this,
dataReceivedEventArgs
});
return;
}
errorDataReceived(this, dataReceivedEventArgs);
}
}
}
internal class AsyncStreamReader : IDisposable
{
internal const int DefaultBufferSize = 1024;
private const int MinBufferSize = 128;
private Stream stream;
private Encoding encoding;
private Decoder decoder;
private byte[] byteBuffer;
private char[] charBuffer;
private int _maxCharsPerBuffer;
private Process process;
private UserCallBack userCallBack;
private bool cancelOperation;
private ManualResetEvent eofEvent;
private Queue messageQueue;
private StringBuilder sb;
private bool bLastCarriageReturn;
public virtual Encoding CurrentEncoding
{
get
{
return this.encoding;
}
}
public virtual Stream BaseStream
{
get
{
return this.stream;
}
}
internal AsyncStreamReader(Process process, Stream stream, UserCallBack callback, Encoding encoding)
: this(process, stream, callback, encoding, 1024)
{
}
internal AsyncStreamReader(Process process, Stream stream, UserCallBack callback, Encoding encoding, int bufferSize)
{
this.Init(process, stream, callback, encoding, bufferSize);
this.messageQueue = new Queue();
}
private void Init(Process process, Stream stream, UserCallBack callback, Encoding encoding, int bufferSize)
{
this.process = process;
this.stream = stream;
this.encoding = encoding;
this.userCallBack = callback;
this.decoder = encoding.GetDecoder();
if (bufferSize < 128)
{
bufferSize = 128;
}
this.byteBuffer = new byte[bufferSize];
this._maxCharsPerBuffer = encoding.GetMaxCharCount(bufferSize);
this.charBuffer = new char[this._maxCharsPerBuffer];
this.cancelOperation = false;
this.eofEvent = new ManualResetEvent(false);
this.sb = null;
this.bLastCarriageReturn = false;
}
public virtual void Close()
{
this.Dispose(true);
}
void IDisposable.Dispose()
{
this.Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (disposing && this.stream != null)
{
this.stream.Close();
}
if (this.stream != null)
{
this.stream = null;
this.encoding = null;
this.decoder = null;
this.byteBuffer = null;
this.charBuffer = null;
}
if (this.eofEvent != null)
{
this.eofEvent.Close();
this.eofEvent = null;
}
}
internal void BeginReadLine()
{
if (this.cancelOperation)
{
this.cancelOperation = false;
}
if (this.sb == null)
{
this.sb = new StringBuilder(1024);
this.stream.BeginRead(this.byteBuffer, 0, this.byteBuffer.Length, new AsyncCallback(this.ReadBuffer), null);
return;
}
this.FlushMessageQueue();
}
internal void CancelOperation()
{
this.cancelOperation = true;
}
private void ReadBuffer(IAsyncResult ar)
{
int num;
try
{
num = this.stream.EndRead(ar);
}
catch (IOException)
{
num = 0;
}
catch (OperationCanceledException)
{
num = 0;
}
if (num == 0)
{
lock (this.messageQueue)
{
if (this.sb.Length != 0)
{
this.messageQueue.Enqueue(this.sb.ToString());
this.sb.Length = 0;
}
this.messageQueue.Enqueue(null);
}
try
{
this.FlushMessageQueue();
return;
}
finally
{
this.eofEvent.Set();
}
}
int chars = this.decoder.GetChars(this.byteBuffer, 0, num, this.charBuffer, 0);
this.sb.Append(this.charBuffer, 0, chars);
this.GetLinesFromStringBuilder();
this.stream.BeginRead(this.byteBuffer, 0, this.byteBuffer.Length, new AsyncCallback(this.ReadBuffer), null);
}
private void GetLinesFromStringBuilder()
{
int i = 0;
int num = 0;
int length = this.sb.Length;
if (this.bLastCarriageReturn && length > 0 && this.sb[0] == '\n')
{
i = 1;
num = 1;
this.bLastCarriageReturn = false;
}
while (i < length)
{
char c = this.sb[i];
if (c == '\r' || c == '\n')
{
if (c == '\r' && i + 1 < length && this.sb[i + 1] == '\n')
{
i++;
}
string obj = this.sb.ToString(num, i + 1 - num);
num = i + 1;
lock (this.messageQueue)
{
this.messageQueue.Enqueue(obj);
}
}
i++;
}
// Flush Fix: Send Whatever is left in the buffer
string endOfBuffer = this.sb.ToString(num, length - num);
lock (this.messageQueue)
{
this.messageQueue.Enqueue(endOfBuffer);
num = length;
}
// End Flush Fix
if (this.sb[length - 1] == '\r')
{
this.bLastCarriageReturn = true;
}
if (num < length)
{
this.sb.Remove(0, num);
}
else
{
this.sb.Length = 0;
}
this.FlushMessageQueue();
}
private void FlushMessageQueue()
{
while (this.messageQueue.Count > 0)
{
lock (this.messageQueue)
{
if (this.messageQueue.Count > 0)
{
string data = (string)this.messageQueue.Dequeue();
if (!this.cancelOperation)
{
this.userCallBack(data);
}
}
continue;
}
break;
}
}
internal void WaitUtilEOF()
{
if (this.eofEvent != null)
{
this.eofEvent.WaitOne();
this.eofEvent.Close();
this.eofEvent = null;
}
}
}
public class DataReceivedEventArgs : EventArgs
{
internal string _data;
/// <summary>Gets the line of characters that was written to a redirected <see cref="T:System.Diagnostics.Process" /> output stream.</summary>
/// <returns>The line that was written by an associated <see cref="T:System.Diagnostics.Process" /> to its redirected <see cref="P:System.Diagnostics.Process.StandardOutput" /> or <see cref="P:System.Diagnostics.Process.StandardError" /> stream.</returns>
/// <filterpriority>2</filterpriority>
public string Data
{
get
{
return this._data;
}
}
internal DataReceivedEventArgs(string data)
{
this._data = data;
}
}
}
坚持，在你的项目，然后改变...
Stick that in your project and then change ...
Process p = new Process()
{
....
到
FixedProcess p = new FixedProcess()
{
....
现在您的应用程序应该会显示这样的事情...
Now your application should display something like this...
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Projects\FixedProcess\bin\Debug>
而无需进行任何其他修改现有的code。它也仍然异步和包裹起来好听。一个需要注意的是，现在你会得到一个很大的输出多个事件与-之间的潜在休息，所以你需要自己处理这种情况。除此之外，它应该是所有好的。
without needing to make any other changes to your existing code. It is also still async and wrapped up nicely. The one caveat is that now you will get multiple events for large output with potential breaks in-between, so you will need to handle this scenario yourself. Other than that, it should be all good.
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