DataReceivedEventHandler デリゲート
アセンブリ: System (system.dll 内)

/** @delegate */ public delegate void DataReceivedEventHandler ( Object sender, DataReceivedEventArgs e )

DataReceivedEventHandler デリゲートを作成する場合は、イベントを処理するメソッドを識別してください。イベントをイベント ハンドラに関連付けるには、デリゲートのインスタンスをイベントに追加します。デリゲートを削除しない限り、そのイベントが発生すると常にイベント ハンドラが呼び出されます。イベント ハンドラ デリゲートの詳細については、「イベントとデリゲート」を参照してください。
プロセスのリダイレクトされた StandardOutput または StandardError ストリーム出力を非同期に収集するには、イベント ハンドラを OutputDataReceived イベントまたは ErrorDataReceived イベントに追加します。これらのイベントは、プロセスが対応するリダイレクトされたストリームに行を書き込むたびに発生します。リダイレクトされたストリームを閉じると、null 行がイベント ハンドラに送られます。Data プロパティにアクセスする前に、イベント ハンドラがこの条件を検証するようにしてください。たとえば、static メソッド String.IsNullOrEmpty を使用して、イベント ハンドラで Data プロパティを検証できます。

sort コマンドのリダイレクトされた StandardOutput ストリームで、非同期読み取り操作を実行するコード例を次に示します。sort コマンドは、テキスト入力を読み込み、並べ替えを実行するコンソール アプリケーションです。
この例では、SortOutputHandler イベント ハンドラの DataReceivedEventHandler デリゲートを作成して、そのデリゲートを OutputDataReceived イベントに関連付けます。イベント ハンドラは、リダイレクトされた StandardOutput ストリームからテキスト行を受け取った後、そのテキストに書式を設定して画面に出力します。
' Define the namespaces used by this sample. Imports System Imports System.Text Imports System.IO Imports System.Diagnostics Imports System.Threading Imports System.ComponentModel Imports Microsoft.VisualBasic 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 = {0} sorted text line(s) ", _ numOutputLines) 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.ToString() + "] - " _ + outLine.Data) End If End Sub End Class End Namespace
// 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; 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 += new 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); 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.ToString() + "] - " + outLine.Data); } } } }
// 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 ); } } };

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
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System.Diagnostics 名前空間
DataReceivedEventArgs クラス
Process.OutputDataReceived
Process.ErrorDataReceived
System.Diagnostics.Process
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