DataReceivedEventArgs 类

定义

提供有关 OutputDataReceivedErrorDataReceived 事件的数据。

public ref class DataReceivedEventArgs : EventArgs
public class DataReceivedEventArgs : EventArgs
type DataReceivedEventArgs = class
    inherit EventArgs
Public Class DataReceivedEventArgs
Inherits EventArgs
继承
DataReceivedEventArgs

示例

下面的代码示例演示如何对命令的重定向 StandardOutputsort 执行异步读取操作。 命令 sort 是一个控制台应用程序,用于读取和排序文本输入。

该示例为 SortOutputHandler 事件处理程序创建一个事件委托,并将其与 OutputDataReceived 事件相关联。 事件处理程序从重定向 StandardOutput 的流接收文本行,设置文本的格式,并将文本写入屏幕。

// Define the namespaces used by this sample.
#using <System.dll>

using namespace System;
using namespace System::Text;
using namespace System::IO;
using namespace System::Diagnostics;
using namespace System::Threading;
using namespace System::ComponentModel;

ref class SortOutputRedirection
{
private:
   // Define static variables shared by class methods.
   static StringBuilder^ sortOutput = nullptr;
   static int numOutputLines = 0;

public:
   static void SortInputListText()
   {
      // Initialize the process and its StartInfo properties.
      // The sort command is a console application that
      // reads and sorts text input.

      Process^ sortProcess;
      sortProcess = gcnew Process;
      sortProcess->StartInfo->FileName = "Sort.exe";
      
      // Set UseShellExecute to false for redirection.
      sortProcess->StartInfo->UseShellExecute = false;
      
      // Redirect the standard output of the sort command.  
      // This stream is read asynchronously using an event handler.
      sortProcess->StartInfo->RedirectStandardOutput = true;
      sortOutput = gcnew StringBuilder;
      
      // Set our event handler to asynchronously read the sort output.
      sortProcess->OutputDataReceived += gcnew DataReceivedEventHandler( SortOutputHandler );
      
      // Redirect standard input as well.  This stream
      // is used synchronously.
      sortProcess->StartInfo->RedirectStandardInput = true;
      
      // Start the process.
      sortProcess->Start();
      
      // Use a stream writer to synchronously write the sort input.
      StreamWriter^ sortStreamWriter = sortProcess->StandardInput;
      
      // Start the asynchronous read of the sort output stream.
      sortProcess->BeginOutputReadLine();
      
      // Prompt the user for input text lines.  Write each 
      // line to the redirected input stream of the sort command.
      Console::WriteLine( "Ready to sort up to 50 lines of text" );

      String^ inputText;
      int numInputLines = 0;
      do
      {
         Console::WriteLine( "Enter a text line (or press the Enter key to stop):" );

         inputText = Console::ReadLine();
         if (  !String::IsNullOrEmpty( inputText ) )
         {
            numInputLines++;
            sortStreamWriter->WriteLine( inputText );
         }
      }
      while (  !String::IsNullOrEmpty( inputText ) && (numInputLines < 50) );

      Console::WriteLine( "<end of input stream>" );
      Console::WriteLine();
      
      // End the input stream to the sort command.
      sortStreamWriter->Close();
      
      // Wait for the sort process to write the sorted text lines.
      sortProcess->WaitForExit();

      if ( numOutputLines > 0 )
      {
         
         // Write the formatted and sorted output to the console.
         Console::WriteLine( " Sort results = {0} sorted text line(s) ",
            numOutputLines.ToString() );
         Console::WriteLine( "----------" );
         Console::WriteLine( sortOutput->ToString() );
      }
      else
      {
         Console::WriteLine( " No input lines were sorted." );
      }

      sortProcess->Close();
   }

private:
   static void SortOutputHandler( Object^ /*sendingProcess*/,
      DataReceivedEventArgs^ outLine )
   {
      // Collect the sort command output.
      if (  !String::IsNullOrEmpty( outLine->Data ) )
      {
         numOutputLines++;
         
         // Add the text to the collected output.
         sortOutput->AppendFormat( "\n[{0}] {1}",
            numOutputLines.ToString(), outLine->Data );
      }
   }
};

/// The main entry point for the application.
void main()
{
   try
   {
      SortOutputRedirection::SortInputListText();
   }
   catch ( InvalidOperationException^ e ) 
   {
      Console::WriteLine( "Exception:" );
      Console::WriteLine( e );
   }
}
// Define the namespaces used by this sample.
using System;
using System.Text;
using System.IO;
using System.Diagnostics;
using System.Threading;
using System.ComponentModel;

namespace ProcessAsyncStreamSamples
{
    class SortOutputRedirection
    {
        // Define static variables shared by class methods.
        private static StringBuilder sortOutput = null;
        private static int numOutputLines = 0;

        public static void SortInputListText()
        {
            // Initialize the process and its StartInfo properties.
            // The sort command is a console application that
            // reads and sorts text input.

            Process sortProcess = new Process();
            sortProcess.StartInfo.FileName = "Sort.exe";

            // Set UseShellExecute to false for redirection.
            sortProcess.StartInfo.UseShellExecute = false;

            // Redirect the standard output of the sort command.
            // This stream is read asynchronously using an event handler.
            sortProcess.StartInfo.RedirectStandardOutput = true;
            sortOutput = new StringBuilder();

            // Set our event handler to asynchronously read the sort output.
            sortProcess.OutputDataReceived += SortOutputHandler;

            // Redirect standard input as well.  This stream
            // is used synchronously.
            sortProcess.StartInfo.RedirectStandardInput = true;

            // Start the process.
            sortProcess.Start();

            // Use a stream writer to synchronously write the sort input.
            StreamWriter sortStreamWriter = sortProcess.StandardInput;

            // Start the asynchronous read of the sort output stream.
            sortProcess.BeginOutputReadLine();

            // Prompt the user for input text lines.  Write each
            // line to the redirected input stream of the sort command.
            Console.WriteLine("Ready to sort up to 50 lines of text");

            String inputText;
            int numInputLines = 0;
            do
            {
                Console.WriteLine("Enter a text line (or press the Enter key to stop):");

                inputText = Console.ReadLine();
                if (!String.IsNullOrEmpty(inputText))
                {
                    numInputLines++;
                    sortStreamWriter.WriteLine(inputText);
                }
            }
            while (!String.IsNullOrEmpty(inputText) && (numInputLines < 50));
            Console.WriteLine("<end of input stream>");
            Console.WriteLine();

            // End the input stream to the sort command.
            sortStreamWriter.Close();

            // Wait for the sort process to write the sorted text lines.
            sortProcess.WaitForExit();

            if (numOutputLines > 0)
            {
                // Write the formatted and sorted output to the console.
                Console.WriteLine($" Sort results = {numOutputLines} sorted text line(s) ");
                Console.WriteLine("----------");
                Console.WriteLine(sortOutput);
            }
            else
            {
                Console.WriteLine(" No input lines were sorted.");
            }

            sortProcess.Close();
        }

        private static void SortOutputHandler(object sendingProcess,
            DataReceivedEventArgs outLine)
        {
            // Collect the sort command output.
            if (!String.IsNullOrEmpty(outLine.Data))
            {
                numOutputLines++;

                // Add the text to the collected output.
                sortOutput.Append(Environment.NewLine +
                    $"[{numOutputLines}] - {outLine.Data}");
            }
        }
    }
}

namespace ProcessAsyncStreamSamples
{

    class ProcessSampleMain
    {
        /// The main entry point for the application.
        static void Main()
        {
            try
            {
                SortOutputRedirection.SortInputListText();
            }
            catch (InvalidOperationException e)
            {
                Console.WriteLine("Exception:");
                Console.WriteLine(e);
            }
        }
    }
}
' Define the namespaces used by this sample.
Imports System.Text
Imports System.IO
Imports System.Diagnostics
Imports System.Threading
Imports System.ComponentModel

Namespace ProcessAsyncStreamSamples

    Class ProcessAsyncOutputRedirection
        ' Define static variables shared by class methods.
        Private Shared sortOutput As StringBuilder = Nothing
        Private Shared numOutputLines As Integer = 0

        Public Shared Sub SortInputListText()

            ' Initialize the process and its StartInfo properties.
            ' The sort command is a console application that
            ' reads and sorts text input.
            Dim sortProcess As New Process()
            sortProcess.StartInfo.FileName = "Sort.exe"

            ' Set UseShellExecute to false for redirection.
            sortProcess.StartInfo.UseShellExecute = False

            ' Redirect the standard output of the sort command.  
            ' Read the stream asynchronously using an event handler.
            sortProcess.StartInfo.RedirectStandardOutput = True
            sortOutput = New StringBuilder()

            ' Set our event handler to asynchronously read the sort output.
            AddHandler sortProcess.OutputDataReceived, AddressOf SortOutputHandler

            ' Redirect standard input as well.  This stream
            ' is used synchronously.
            sortProcess.StartInfo.RedirectStandardInput = True

            ' Start the process.
            sortProcess.Start()

            ' Use a stream writer to synchronously write the sort input.
            Dim sortStreamWriter As StreamWriter = sortProcess.StandardInput

            ' Start the asynchronous read of the sort output stream.
            sortProcess.BeginOutputReadLine()

            ' Prompt the user for input text lines.  Write each 
            ' line to the redirected input stream of the sort command.
            Console.WriteLine("Ready to sort up to 50 lines of text")

            Dim inputText As String
            Dim numInputLines As Integer = 0
            Do
                Console.WriteLine("Enter a text line (or press the Enter key to stop):")

                inputText = Console.ReadLine()
                If Not String.IsNullOrEmpty(inputText) Then
                    numInputLines += 1
                    sortStreamWriter.WriteLine(inputText)
                End If
            Loop While Not String.IsNullOrEmpty(inputText) AndAlso numInputLines < 50
            Console.WriteLine("<end of input stream>")
            Console.WriteLine()

            ' End the input stream to the sort command.
            sortStreamWriter.Close()

            ' Wait for the sort process to write the sorted text lines.
            sortProcess.WaitForExit()

            If Not String.IsNullOrEmpty(numOutputLines) Then
                ' Write the formatted and sorted output to the console.
                Console.WriteLine($" Sort results = {numOutputLines} sorted text line(s) ")
                Console.WriteLine("----------")
                Console.WriteLine(sortOutput)
            Else
                Console.WriteLine(" No input lines were sorted.")
            End If

            sortProcess.Close()
        End Sub

        Private Shared Sub SortOutputHandler(sendingProcess As Object,
           outLine As DataReceivedEventArgs)

            ' Collect the sort command output.
            If Not String.IsNullOrEmpty(outLine.Data) Then
                numOutputLines += 1

                ' Add the text to the collected output.
                sortOutput.Append(Environment.NewLine +
                    $"[{numOutputLines}] - {outLine.Data}")
            End If
        End Sub
    End Class
End Namespace

Namespace ProcessAsyncStreamSamples

    Class ProcessSampleMain

        ' The main entry point for the application.
        Shared Sub Main()
            Try
                ProcessAsyncOutputRedirection.SortInputListText()

            Catch e As InvalidOperationException
                Console.WriteLine("Exception:")
                Console.WriteLine(e)
            End Try
        End Sub
    End Class  'ProcessSampleMain
End Namespace 'Process_AsyncStream_Sample

注解

若要异步收集进程的重定向 StandardOutputStandardError 流输出,必须创建处理重定向的流输出事件的方法。 当进程写入重定向的流时,将调用事件处理程序方法。 事件委托使用 实例 DataReceivedEventArgs调用事件处理程序。 属性 Data 包含进程写入重定向流的文本行。

属性

Data

获取写入到重定向 Process 输出流的字符行。

方法

Equals(Object)

确定指定对象是否等于当前对象。

(继承自 Object)
GetHashCode()

作为默认哈希函数。

(继承自 Object)
GetType()

获取当前实例的 Type

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。

(继承自 Object)
ToString()

返回表示当前对象的字符串。

(继承自 Object)

适用于

另请参阅