c# - 异步读取进程输出时的延迟

Question

我正在使用 .NET 和 C# 启动一个进程并异步读取它的输出。我的问题是在我的程序读取输出之前似乎有延迟。如果我在命令行上运行可执行文件，它开始运行时会立即有输出。但是当我使用我的代码运行它时，ReadOutput 事件处理程序直到进程退出才被调用。我想使用它来提供进程输出的实时 View ，所以我不想等待(几分钟)直到进程退出。

这里是一些相关的代码:

MyProcess = new Process();
MyProcess.StartInfo.FileName = command;
MyProcess.StartInfo.Arguments = args;
MyProcess.StartInfo.UseShellExecute = false;
MyProcess.StartInfo.RedirectStandardOutput = true;
MyProcess.StartInfo.RedirectStandardError = true;
MyProcess.StartInfo.RedirectStandardInput = true;
MyProcess.OutputDataReceived += new DataReceivedEventHandler(ReadOutput);
MyProcess.ErrorDataReceived += new DataReceivedEventHandler(ReadOutput);

if (!MyProcess.Start())
{
    throw new Exception("Process could not be started");
}

try
{
    MyProcess.BeginOutputReadLine();
    MyProcess.BeginErrorReadLine();
}
catch (Exception ex)
{
    throw new Exception("Unable to begin asynchronous reading from process";
}

这是我的事件处理程序:

private void ReadOutput(object sendingProcess, DataReceivedEventArgs outLine)
{
    OutputBuilder.AppendLine(outLine.Data);
    Console.WriteLine(outLine.Data);
    Console.Out.Flush();
}

Answer 1

根据我使用 lambda 语法的评论，这是我执行此操作的方式 (C# 3)。

    /// <summary>
    /// Collects standard output text from the launched program.
    /// </summary>
    private static readonly StringBuilder outputText = new StringBuilder();

    /// <summary>
    /// Collects standard error text from the launched program.
    /// </summary>
    private static readonly StringBuilder errorText = new StringBuilder();

    /// <summary>
    /// The program's entry point.
    /// </summary>
    /// <param name="args">The command-line arguments.</param>
    /// <returns>The exit code.</returns>
    private static int Main(string[] args)
    {
        using (var process = Process.Start(new ProcessStartInfo(
            "program.exe",
            args)
            {
                CreateNoWindow = true,
                ErrorDialog = false,
                RedirectStandardError = true,
                RedirectStandardOutput = true,
                UseShellExecute = false
            }))
        {
            process.OutputDataReceived += (sendingProcess, outLine) =>
                outputText.AppendLine(outLine.Data);

            process.ErrorDataReceived += (sendingProcess, errorLine) =>
                errorText.AppendLine(errorLine.Data);

            process.BeginOutputReadLine();
            process.BeginErrorReadLine();
            process.WaitForExit();
            Console.WriteLine(errorText.ToString());
            Console.WriteLine(outputText.ToString());
            return process.ExitCode;
        }