我从C#启动一个进程如下：
public bool Execute()
{
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.Arguments = "the command";
startInfo.FileName = "C:\\MyApp.exe";
startInfo.UseShellExecute = false;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError = true;
Log.LogMessage("{0} {1}",startInfo.FileName,startInfo.Arguments);
using (Process myProcess = Process.Start(startInfo))
{
StringBuilder output = new StringBuilder();
myProcess.OutputDataReceived += delegate(object sender,DataReceivedEventArgs e)
{
Log.LogMessage(Thread.CurrentThread.ManagedThreadId.ToString() + e.Data);
};
myProcess.ErrorDataReceived += delegate(object sender,DataReceivedEventArgs e)
{
Log.LogError(Thread.CurrentThread.ManagedThreadId.ToString() + " " + e.Data);
};
myProcess.BeginErrorReadLine();
myProcess.BeginOutputReadLine();
myProcess.WaitForExit();
}
return false;
}
但是这有一个问题…如果有问题的应用程序按照这个顺序写入std out和std err：
std out: msg 1 std err: msg 2 std out: msg 3
那么我从日志中看到的输出是：
msg 2 msg 1 msg 3
这似乎是因为事件处理程序在另一个线程中执行.所以我的问题是如何保持流程写入std err和std out的顺序？
我想到使用时间戳,但我不认为这将工作,由于线程的抢先的性质.
更新：确认在数据上使用时间戳是没有用的.
最终更新：接受的答案解决了这个问题 – 但是它有一个缺点,当流合并时,无法知道哪个流被写入.因此,如果您需要写入stderr ==失败的逻辑,而不是应用程序退出代码,那么您仍然可以拧紧.
解决方法
据了解,您希望保留stdout / stderr消息的顺序.我没有看到任何DECENT的方法来做到这一点与C#管理的过程(反思 – 是的,讨厌的子类黑客 – 是的).看来它几乎是硬编码.
此功能不依赖于线程本身.如果要保持顺序,STDOUT和STDERROR必须使用相同的句柄(缓冲区).如果他们使用相同的缓冲区,它将被同步.
这是Process.cs的一个片段：
if (startInfo.RedirectStandardOutput) {
CreatePipe(out standardOutputReadPipeHandle,out startupInfo.hStdOutput,false);
} else {
startupInfo.hStdOutput = new SafeFileHandle(
NativeMethods.GetStdHandle(
NativeMethods.STD_OUTPUT_HANDLE),false);
}
if (startInfo.RedirectStandardError) {
CreatePipe(out standardErrorReadPipeHandle,out startupInfo.hStdError,false);
} else {
startupInfo.hStdError = new SafeFileHandle(
NativeMethods.GetStdHandle(
NativeMethods.STD_ERROR_HANDLE),false);
}
如你所见,会有两个缓冲区,如果我们有两个缓冲区,我们已经丢失了订单信息.
基本上,您需要创建可以处理这种情况的您自己的Process()类.伤心？是.
好消息是,这不难,看起来很简单.这是从StackOverflow获取的代码,不是C#,但足以理解算法：
function StartProcessWithRedirectedOutput(const ACommandLine: string; const AOutputFile: string;
AShowWindow: boolean = True; AWaitForFinish: boolean = False): Integer;
var
CommandLine: string;
StartupInfo: TStartupInfo;
ProcessInformation: TProcessInformation;
StdOutFileHandle: THandle;
begin
Result := 0;
StdOutFileHandle := CreateFile(PChar(AOutputFile),GENERIC_WRITE,FILE_SHARE_READ,nil,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0);
Win32Check(StdOutFileHandle <> INVALID_HANDLE_VALUE);
try
Win32Check(SetHandleInformation(StdOutFileHandle,HANDLE_FLAG_INHERIT,1));
FillChar(StartupInfo,SizeOf(TStartupInfo),0);
FillChar(ProcessInformation,SizeOf(TProcessInformation),0);
StartupInfo.cb := SizeOf(TStartupInfo);
StartupInfo.dwFlags := StartupInfo.dwFlags or STARTF_USESTDHANDLES;
StartupInfo.hStdInput := GetStdHandle(STD_INPUT_HANDLE);
StartupInfo.hStdOutput := StdOutFileHandle;
StartupInfo.hStdError := StdOutFileHandle;
if not(AShowWindow) then
begin
StartupInfo.dwFlags := StartupInfo.dwFlags or STARTF_USESHOWWINDOW;
StartupInfo.wShowWindow := SW_HIDE;
end;
CommandLine := ACommandLine;
UniqueString(CommandLine);
Win32Check(CreateProcess(nil,PChar(CommandLine),True,CREATE_NEW_PROCESS_GROUP + NORMAL_PRIORITY_CLASS,StartupInfo,ProcessInformation));
try
Result := ProcessInformation.dwProcessId;
if AWaitForFinish then
WaitForSingleObject(ProcessInformation.hProcess,INFINITE);
finally
CloseHandle(ProcessInformation.hProcess);
CloseHandle(ProcessInformation.hThread);
end;
finally
CloseHandle(StdOutFileHandle);
end;
end;
资料来源：How to redirect large amount of output from command executed by CreateProcess?
而不是文件,你想使用CreatePipe.从管道,您可以像这样读取异步：
standardOutput = new StreamReader(new FileStream(
standardOutputReadPipeHandle,FileAccess.Read,4096,false),enc,true,4096);
和BeginReadOutput()
if (output == null) {
Stream s = standardOutput.BaseStream;
output = new AsyncStreamReader(this,s,new UserCallBack(this.OutputReadNotifyUser),standardOutput.CurrentEncoding);
}
output.BeginReadLine();
