DataReceivedEventArgs.Data 屬性

定義

命名空間:

System.Diagnostics

組件:

System.Diagnostics.Process.dll

來源:

DataReceivedEventArgs.cs

取得已寫入至重新導向 Process 輸出資料流的字元行。

public:
 property System::String ^ Data { System::String ^ get(); };

public string? Data { get; }

member this.Data : string

Public ReadOnly Property Data As String

屬性值

String

由關聯的 Process 寫入至其重新導向的 StandardOutput 或 StandardError 資料流的字行。

範例

下列程式代碼範例說明與 事件相關聯的 OutputDataReceived 簡單事件處理程式。 事件處理程式會從重新導向 StandardOutput 的數據流接收文字行、格式化文字，並將文字寫入畫面。

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

ref class StandardAsyncOutputExample
{
private:
    static int lineCount = 0;
    static StringBuilder^ output = nullptr;

public:
    static void Run()
    {
        Process^ process = gcnew Process();
        process->StartInfo->FileName = "ipconfig.exe";
        process->StartInfo->UseShellExecute = false;
        process->StartInfo->RedirectStandardOutput = true;
        output = gcnew StringBuilder();
        process->OutputDataReceived += gcnew DataReceivedEventHandler(OutputHandler);
        process->Start();

        // Asynchronously read the standard output of the spawned process. 
        // This raises OutputDataReceived events for each line of output.
        process->BeginOutputReadLine();
        process->WaitForExit();

        // Write the redirected output to this application's window.
        Console::WriteLine(output);

        process->WaitForExit();
        process->Close();

        Console::WriteLine("\n\nPress any key to exit");
        Console::ReadLine();
    }

private:
    static void OutputHandler(Object^ sender, DataReceivedEventArgs^ e)
    {
        // Prepend line numbers to each line of the output.
        if (!String::IsNullOrEmpty(e->Data))
        {
            lineCount++;
            output->Append("\n[" + lineCount + "]: " + e->Data);
        }
    }
};

int main()
{
    StandardAsyncOutputExample::Run();
}

using System;
using System.IO;
using System.Diagnostics;
using System.Text;

class StandardAsyncOutputExample
{
    private static int lineCount = 0;
    private static StringBuilder output = new StringBuilder();

    public static void Main()
    {
        Process process = new Process();
        process.StartInfo.FileName = "ipconfig.exe";
        process.StartInfo.UseShellExecute = false;
        process.StartInfo.RedirectStandardOutput = true;
        process.OutputDataReceived += new DataReceivedEventHandler((sender, e) =>
        {
            // Prepend line numbers to each line of the output.
            if (!String.IsNullOrEmpty(e.Data))
            {
                lineCount++;
                output.Append("\n[" + lineCount + "]: " + e.Data);
            }
        });

        process.Start();

        // Asynchronously read the standard output of the spawned process.
        // This raises OutputDataReceived events for each line of output.
        process.BeginOutputReadLine();
        process.WaitForExit();

        // Write the redirected output to this application's window.
        Console.WriteLine(output);

        process.WaitForExit();
        process.Close();

        Console.WriteLine("\n\nPress any key to exit.");
        Console.ReadLine();
    }
}

Imports System.IO
Imports System.Diagnostics
Imports System.Text

Module Module1
    Dim lineCount As Integer = 0
    Dim output As StringBuilder = New StringBuilder()

    Sub Main()
        Dim process As New Process()
        process.StartInfo.FileName = "ipconfig.exe"
        process.StartInfo.UseShellExecute = False
        process.StartInfo.RedirectStandardOutput = True
        AddHandler process.OutputDataReceived, AddressOf OutputHandler
        process.Start()

        ' Asynchronously read the standard output of the spawned process. 
        ' This raises OutputDataReceived events for each line of output.
        process.BeginOutputReadLine()
        process.WaitForExit()

        Console.WriteLine(output)

        process.WaitForExit()
        process.Close()

        Console.WriteLine(Environment.NewLine + Environment.NewLine + "Press any key to exit.")
        Console.ReadLine()
    End Sub

    Sub OutputHandler(sender As Object, e As DataReceivedEventArgs)
        If Not String.IsNullOrEmpty(e.Data) Then
            lineCount += 1

            ' Add the text to the collected output.
            output.Append(Environment.NewLine + "[" + lineCount.ToString() + "]: " + e.Data)
        End If
    End Sub
End Module

備註

當您將 StandardOutput 的 或 StandardError 數據流 Process 重新導向至事件處理程式時，每次進程將一行寫入重新導向的數據流時，就會引發事件。 屬性 Data 是寫入至重新導向輸出數據流的行 Process 。 事件處理程式可以使用 Data 屬性來篩選進程輸出，或將輸出寫入替代位置。 例如，您可以建立事件處理程式，將所有錯誤輸出行儲存到指定的錯誤記錄檔中。

行定義為字元序列，後面接著換行字元 (“\n”) ，或緊接著換行字元 (“\r\n”) 。 行字元會使用預設系統 ANSI 代碼頁進行編碼。 屬性 Data 不包含終止歸位字元或換行字元。

當重新導向的數據流關閉時，會將 Null 行傳送至事件處理程式。 在存取屬性之前， Data 請確定事件處理程式會先適當地檢查屬性。 例如，您可以使用靜態方法來 String.IsNullOrEmpty 驗證 Data 事件處理程式中的屬性。