Process.BeginErrorReadLine 메서드
정의
중요
일부 정보는 릴리스되기 전에 상당 부분 수정될 수 있는 시험판 제품과 관련이 있습니다. Microsoft는 여기에 제공된 정보에 대해 어떠한 명시적이거나 묵시적인 보증도 하지 않습니다.
애플리케이션의 리디렉션된 StandardError 스트림에 대해 비동기 읽기 작업을 시작합니다.
public:
void BeginErrorReadLine();
public void BeginErrorReadLine ();
[System.Runtime.InteropServices.ComVisible(false)]
public void BeginErrorReadLine ();
member this.BeginErrorReadLine : unit -> unit
[<System.Runtime.InteropServices.ComVisible(false)>]
member this.BeginErrorReadLine : unit -> unit
Public Sub BeginErrorReadLine ()
- 특성
예외
RedirectStandardError 속성은 false
입니다.
또는
StandardError 스트림에서 비동기 읽기 작업이 이미 진행 중입니다.
또는
StandardError 스트림이 동기적 읽기 작업에 사용되었습니다.
예제
다음 예제에서는 net view
명령을 사용하여 원격 컴퓨터에서 사용 가능한 네트워크 리소스를 나열합니다. 사용자는 대상 컴퓨터 이름을 명령줄 인수로 제공합니다. 사용자는 오류 출력에 대한 파일 이름을 제공할 수도 있습니다. 이 예제에서는 net 명령의 출력을 수집하고 프로세스가 완료되기를 기다린 다음 출력 결과를 콘솔에 씁니다. 사용자가 선택적 오류 파일을 제공하는 경우 예제에서는 파일에 오류를 씁니다.
// Define the namespaces used by this sample.
#using <System.dll>
using namespace System;
using namespace System::Text;
using namespace System::Globalization;
using namespace System::IO;
using namespace System::Diagnostics;
using namespace System::Threading;
using namespace System::ComponentModel;
ref class ProcessNetStreamRedirection
{
private:
// Define static variables shared by class methods.
static StreamWriter^ streamError = nullptr;
static String^ netErrorFile = "";
static StringBuilder^ netOutput = nullptr;
static bool errorRedirect = false;
static bool errorsWritten = false;
public:
static void RedirectNetCommandStreams()
{
String^ netArguments;
Process^ netProcess;
// Get the input computer name.
Console::WriteLine( "Enter the computer name for the net view command:" );
netArguments = Console::ReadLine()->ToUpper( CultureInfo::InvariantCulture );
if ( String::IsNullOrEmpty( netArguments ) )
{
// Default to the help command if there is not an input argument.
netArguments = "/?";
}
// Check if errors should be redirected to a file.
errorsWritten = false;
Console::WriteLine( "Enter a fully qualified path to an error log file" );
Console::WriteLine( " or just press Enter to write errors to console:" );
netErrorFile = Console::ReadLine()->ToUpper( CultureInfo::InvariantCulture );
if ( !String::IsNullOrEmpty( netErrorFile ) )
{
errorRedirect = true;
}
// Note that at this point, netArguments and netErrorFile
// are set with user input. If the user did not specify
// an error file, then errorRedirect is set to false.
// Initialize the process and its StartInfo properties.
netProcess = gcnew Process;
netProcess->StartInfo->FileName = "Net.exe";
// Build the net command argument list.
netProcess->StartInfo->Arguments = String::Format( "view {0}", netArguments );
// Set UseShellExecute to false for redirection.
netProcess->StartInfo->UseShellExecute = false;
// Redirect the standard output of the net command.
// This stream is read asynchronously using an event handler.
netProcess->StartInfo->RedirectStandardOutput = true;
netProcess->OutputDataReceived += gcnew DataReceivedEventHandler( NetOutputDataHandler );
netOutput = gcnew StringBuilder;
if ( errorRedirect )
{
// Redirect the error output of the net command.
netProcess->StartInfo->RedirectStandardError = true;
netProcess->ErrorDataReceived += gcnew DataReceivedEventHandler( NetErrorDataHandler );
}
else
{
// Do not redirect the error output.
netProcess->StartInfo->RedirectStandardError = false;
}
Console::WriteLine( "\nStarting process: net {0}",
netProcess->StartInfo->Arguments );
if ( errorRedirect )
{
Console::WriteLine( "Errors will be written to the file {0}", netErrorFile );
}
// Start the process.
netProcess->Start();
// Start the asynchronous read of the standard output stream.
netProcess->BeginOutputReadLine();
if ( errorRedirect )
{
// Start the asynchronous read of the standard
// error stream.
netProcess->BeginErrorReadLine();
}
// Let the net command run, collecting the output.
netProcess->WaitForExit();
if ( streamError != nullptr )
{
// Close the error file.
streamError->Close();
}
else
{
// Set errorsWritten to false if the stream is not
// open. Either there are no errors, or the error
// file could not be opened.
errorsWritten = false;
}
if ( netOutput->Length > 0 )
{
// If the process wrote more than just
// white space, write the output to the console.
Console::WriteLine( "\nPublic network shares from net view:\n{0}\n",
netOutput->ToString() );
}
if ( errorsWritten )
{
// Signal that the error file had something
// written to it.
array<String^>^errorOutput = File::ReadAllLines( netErrorFile );
if ( errorOutput->Length > 0 )
{
Console::WriteLine( "\nThe following error output was appended to {0}.",
netErrorFile );
System::Collections::IEnumerator^ myEnum = errorOutput->GetEnumerator();
while ( myEnum->MoveNext() )
{
String^ errLine = safe_cast<String^>(myEnum->Current);
Console::WriteLine( " {0}", errLine );
}
}
Console::WriteLine();
}
netProcess->Close();
}
private:
static void NetOutputDataHandler( Object^ /*sendingProcess*/,
DataReceivedEventArgs^ outLine )
{
// Collect the net view command output.
if ( !String::IsNullOrEmpty( outLine->Data ) )
{
// Add the text to the collected output.
netOutput->AppendFormat( "\n {0}", outLine->Data );
}
}
static void NetErrorDataHandler( Object^ /*sendingProcess*/,
DataReceivedEventArgs^ errLine )
{
// Write the error text to the file if there is something to
// write and an error file has been specified.
if ( !String::IsNullOrEmpty( errLine->Data ) )
{
if ( !errorsWritten )
{
if ( streamError == nullptr )
{
// Open the file.
try
{
streamError = gcnew StreamWriter( netErrorFile,true );
}
catch ( Exception^ e )
{
Console::WriteLine( "Could not open error file!" );
Console::WriteLine( e->Message->ToString() );
}
}
if ( streamError != nullptr )
{
// Write a header to the file if this is the first
// call to the error output handler.
streamError->WriteLine();
streamError->WriteLine( DateTime::Now.ToString() );
streamError->WriteLine( "Net View error output:" );
}
errorsWritten = true;
}
if ( streamError != nullptr )
{
// Write redirected errors to the file.
streamError->WriteLine( errLine->Data );
streamError->Flush();
}
}
}
};
// Define the namespaces used by this sample.
using System;
using System.Text;
using System.Globalization;
using System.IO;
using System.Diagnostics;
using System.Threading;
using System.ComponentModel;
namespace ProcessAsyncStreamSamples
{
class ProcessNetStreamRedirection
{
// Define static variables shared by class methods.
private static StreamWriter streamError =null;
private static String netErrorFile = "";
private static StringBuilder netOutput = null;
private static bool errorRedirect = false;
private static bool errorsWritten = false;
public static void RedirectNetCommandStreams()
{
String netArguments;
Process netProcess;
// Get the input computer name.
Console.WriteLine("Enter the computer name for the net view command:");
netArguments = Console.ReadLine().ToUpper(CultureInfo.InvariantCulture);
if (String.IsNullOrEmpty(netArguments))
{
// Default to the help command if there is not an input argument.
netArguments = "/?";
}
// Check if errors should be redirected to a file.
errorsWritten = false;
Console.WriteLine("Enter a fully qualified path to an error log file");
Console.WriteLine(" or just press Enter to write errors to console:");
netErrorFile = Console.ReadLine().ToUpper(CultureInfo.InvariantCulture);
if (!String.IsNullOrEmpty(netErrorFile))
{
errorRedirect = true;
}
// Note that at this point, netArguments and netErrorFile
// are set with user input. If the user did not specify
// an error file, then errorRedirect is set to false.
// Initialize the process and its StartInfo properties.
netProcess = new Process();
netProcess.StartInfo.FileName = "Net.exe";
// Build the net command argument list.
netProcess.StartInfo.Arguments = String.Format("view {0}",
netArguments);
// Set UseShellExecute to false for redirection.
netProcess.StartInfo.UseShellExecute = false;
// Redirect the standard output of the net command.
// This stream is read asynchronously using an event handler.
netProcess.StartInfo.RedirectStandardOutput = true;
netProcess.OutputDataReceived += new DataReceivedEventHandler(NetOutputDataHandler);
netOutput = new StringBuilder();
if (errorRedirect)
{
// Redirect the error output of the net command.
netProcess.StartInfo.RedirectStandardError = true;
netProcess.ErrorDataReceived += new DataReceivedEventHandler(NetErrorDataHandler);
}
else
{
// Do not redirect the error output.
netProcess.StartInfo.RedirectStandardError = false;
}
Console.WriteLine("\nStarting process: net {0}",
netProcess.StartInfo.Arguments);
if (errorRedirect)
{
Console.WriteLine("Errors will be written to the file {0}",
netErrorFile);
}
// Start the process.
netProcess.Start();
// Start the asynchronous read of the standard output stream.
netProcess.BeginOutputReadLine();
if (errorRedirect)
{
// Start the asynchronous read of the standard
// error stream.
netProcess.BeginErrorReadLine();
}
// Let the net command run, collecting the output.
netProcess.WaitForExit();
if (streamError != null)
{
// Close the error file.
streamError.Close();
}
else
{
// Set errorsWritten to false if the stream is not
// open. Either there are no errors, or the error
// file could not be opened.
errorsWritten = false;
}
if (netOutput.Length > 0)
{
// If the process wrote more than just
// white space, write the output to the console.
Console.WriteLine("\nPublic network shares from net view:\n{0}\n",
netOutput);
}
if (errorsWritten)
{
// Signal that the error file had something
// written to it.
String [] errorOutput = File.ReadAllLines(netErrorFile);
if (errorOutput.Length > 0)
{
Console.WriteLine("\nThe following error output was appended to {0}.",
netErrorFile);
foreach (String errLine in errorOutput)
{
Console.WriteLine(" {0}", errLine);
}
}
Console.WriteLine();
}
netProcess.Close();
}
private static void NetOutputDataHandler(object sendingProcess,
DataReceivedEventArgs outLine)
{
// Collect the net view command output.
if (!String.IsNullOrEmpty(outLine.Data))
{
// Add the text to the collected output.
netOutput.Append(Environment.NewLine + " " + outLine.Data);
}
}
private static void NetErrorDataHandler(object sendingProcess,
DataReceivedEventArgs errLine)
{
// Write the error text to the file if there is something
// to write and an error file has been specified.
if (!String.IsNullOrEmpty(errLine.Data))
{
if (!errorsWritten)
{
if (streamError == null)
{
// Open the file.
try
{
streamError = new StreamWriter(netErrorFile, true);
}
catch (Exception e)
{
Console.WriteLine("Could not open error file!");
Console.WriteLine(e.Message.ToString());
}
}
if (streamError != null)
{
// Write a header to the file if this is the first
// call to the error output handler.
streamError.WriteLine();
streamError.WriteLine(DateTime.Now.ToString());
streamError.WriteLine("Net View error output:");
}
errorsWritten = true;
}
if (streamError != null)
{
// Write redirected errors to the file.
streamError.WriteLine(errLine.Data);
streamError.Flush();
}
}
}
}
}
' Define the namespaces used by this sample.
Imports System.Text
Imports System.Globalization
Imports System.IO
Imports System.Diagnostics
Imports System.Threading
Imports System.ComponentModel
Namespace ProcessAsyncStreamSamples
Class ProcessAsyncErrorRedirection
' Define static variables shared by class methods.
Private Shared streamError As StreamWriter = Nothing
Private Shared netErrorFile As String = ""
Private Shared netOutput As StringBuilder = Nothing
Private Shared errorRedirect As Boolean = False
Private Shared errorsWritten As Boolean = False
Public Shared Sub RedirectNetCommandStreams()
Dim netArguments As String
Dim netProcess As Process
' Get the input computer name.
Console.WriteLine("Enter the computer name for the net view command:")
netArguments = Console.ReadLine().ToUpper(CultureInfo.InvariantCulture)
If String.IsNullOrEmpty(netArguments) Then
' Default to the help command if there is
' not an input argument.
netArguments = "/?"
End If
' Check if errors should be redirected to a file.
errorsWritten = False
Console.WriteLine("Enter a fully qualified path to an error log file")
Console.WriteLine(" or just press Enter to write errors to console:")
netErrorFile = Console.ReadLine().ToUpper(CultureInfo.InvariantCulture)
If Not String.IsNullOrEmpty(netErrorFile) Then
errorRedirect = True
End If
' Note that at this point, netArguments and netErrorFile
' are set with user input. If the user did not specify
' an error file, then errorRedirect is set to false.
' Initialize the process and its StartInfo properties.
netProcess = New Process()
netProcess.StartInfo.FileName = "Net.exe"
' Build the net command argument list.
netProcess.StartInfo.Arguments = String.Format("view {0}", _
netArguments)
' Set UseShellExecute to false for redirection.
netProcess.StartInfo.UseShellExecute = False
' Redirect the standard output of the net command.
' Read the stream asynchronously using an event handler.
netProcess.StartInfo.RedirectStandardOutput = True
AddHandler netProcess.OutputDataReceived, _
AddressOf NetOutputDataHandler
netOutput = new StringBuilder()
If errorRedirect Then
' Redirect the error output of the net command.
netProcess.StartInfo.RedirectStandardError = True
AddHandler netProcess.ErrorDataReceived, _
AddressOf NetErrorDataHandler
Else
' Do not redirect the error output.
netProcess.StartInfo.RedirectStandardError = False
End If
Console.WriteLine(ControlChars.Lf + "Starting process: NET {0}", _
netProcess.StartInfo.Arguments)
If errorRedirect Then
Console.WriteLine("Errors will be written to the file {0}", _
netErrorFile)
End If
' Start the process.
netProcess.Start()
' Start the asynchronous read of the standard output stream.
netProcess.BeginOutputReadLine()
If errorRedirect Then
' Start the asynchronous read of the standard
' error stream.
netProcess.BeginErrorReadLine()
End If
' Let the net command run, collecting the output.
netProcess.WaitForExit()
If Not streamError Is Nothing Then
' Close the error file.
streamError.Close()
Else
' Set errorsWritten to false if the stream is not
' open. Either there are no errors, or the error
' file could not be opened.
errorsWritten = False
End If
If netOutput.Length > 0 Then
' If the process wrote more than just
' white space, write the output to the console.
Console.WriteLine()
Console.WriteLine("Public network shares from net view:")
Console.WriteLine()
Console.WriteLine(netOutput)
Console.WriteLine()
End If
If errorsWritten Then
' Signal that the error file had something
' written to it.
Dim errorOutput As String()
errorOutput = File.ReadAllLines(netErrorFile)
If errorOutput.Length > 0 Then
Console.WriteLine(ControlChars.Lf + _
"The following error output was appended to {0}.", _
netErrorFile)
Dim errLine as String
For Each errLine in errorOutput
Console.WriteLine(" {0}", errLine)
Next
Console.WriteLine()
End If
End If
netProcess.Close()
End Sub
Private Shared Sub NetOutputDataHandler(sendingProcess As Object, _
outLine As DataReceivedEventArgs)
' Collect the net view command output.
If Not String.IsNullOrEmpty(outLine.Data) Then
' Add the text to the collected output.
netOutput.Append(Environment.NewLine + " " + outLine.Data)
End If
End Sub
Private Shared Sub NetErrorDataHandler(sendingProcess As Object, _
errLine As DataReceivedEventArgs)
' Write the error text to the file if there is something to
' write and an error file has been specified.
If Not String.IsNullOrEmpty(errLine.Data) Then
If Not errorsWritten Then
If streamError Is Nothing Then
' Open the file.
Try
streamError = New StreamWriter(netErrorFile, true)
Catch e As Exception
Console.WriteLine("Could not open error file!")
Console.WriteLine(e.Message.ToString())
End Try
End If
If Not streamError Is Nothing Then
' Write a header to the file if this is the first
' call to the error output handler.
streamError.WriteLine()
streamError.WriteLine(DateTime.Now.ToString())
streamError.WriteLine("Net View error output:")
End If
errorsWritten = True
End If
If Not streamError Is Nothing Then
' Write redirected errors to the file.
streamError.WriteLine(errLine.Data)
streamError.Flush()
End If
End If
End Sub
End Class
End Namespace
설명
스트림은 StandardError 동기적으로 또는 비동기적으로 읽을 수 있습니다. Read, ReadLine, 등의 ReadToEnd 메서드는 프로세스의 오류 출력 스트림에서 동기 읽기 작업을 수행합니다. 이러한 동기 읽기 작업은 연결된 Process 가 스트림 StandardError 에 쓰거나 스트림을 닫을 때까지 완료되지 않습니다.
반면, 는 BeginErrorReadLine 스트림에서 StandardError 비동기 읽기 작업을 시작합니다. 이 메서드는 스트림 출력에 대해 지정된 이벤트 처리기를 사용하도록 설정하고 즉시 호출자에게 반환되며, 이 호출자는 스트림 출력이 이벤트 처리기로 전달되는 동안 다른 작업을 수행할 수 있습니다.
에 대해 비동기 읽기 작업을 수행하려면 다음 단계를 수행합니다 StandardErrorProcess .
UseShellExecute를
false
로 설정합니다.RedirectStandardError를
true
로 설정합니다.이벤트에 이벤트 처리기를 추가합니다 ErrorDataReceived . 이벤트 처리기는 대리자 서명과 System.Diagnostics.DataReceivedEventHandler 일치해야 합니다.
Process를 시작합니다.
를 호출 BeginErrorReadLine 합니다 Process. 이 호출은 에서 StandardError비동기 읽기 작업을 시작합니다.
비동기 읽기 작업이 시작되면 연결된 Process 가 해당 스트림에 텍스트 StandardError 줄을 쓸 때마다 이벤트 처리기가 호출됩니다.
를 호출 CancelErrorRead하여 비동기 읽기 작업을 취소할 수 있습니다. 호출자 또는 이벤트 처리기에서 읽기 작업을 취소할 수 있습니다. 취소한 후 를 다시 호출 BeginErrorReadLine 하여 비동기 읽기 작업을 다시 시작할 수 있습니다.
참고
리디렉션된 스트림에서는 비동기 및 동기 읽기 작업을 혼합할 수 없습니다. 리디렉션된 스트림 Process 이 비동기 또는 동기 모드로 열리면 해당 스트림에 대한 모든 추가 읽기 작업이 동일한 모드에 있어야 합니다. 예를 들어 스트림에서 에 대한 StandardError 호출 ReadLine 을 따르지 BeginErrorReadLine 않거나 그 반대의 경우도 마찬가지입니다. 그러나 서로 다른 모드에서 두 개의 서로 다른 스트림을 읽을 수 있습니다. 예를 들어 를 호출 BeginErrorReadLine 한 다음 스트림을 호출 ReadLine 할 StandardOutput 수 있습니다.
적용 대상
추가 정보
.NET