C#处理实时StandardOutput流

Question

我正在尝试使用Process从我的C#项目中调用rclone，并且还需要从该过程中获得实时输出。

为了实现这一点，我使用下面的代码，可以找到下面的代码：

它是从this post上取来的。

using System;
using System.IO;

namespace Collection_Manager
{
    /// <summary>
    /// Stream reader for StandardOutput and StandardError stream readers
    /// Runs an eternal BeginRead loop on the underlaying stream bypassing the stream reader.
    /// 
    /// The TextReceived sends data received on the stream in non delimited chunks. Event subscriber can
    /// then split on newline characters etc as desired.
    /// </summary>
    class AsyncStreamReader
    {

        public delegate void EventHandler<args>(object sender, string Data);
        public event EventHandler<string> DataReceived;

        protected readonly byte[] buffer = new byte[4096];
        private StreamReader reader;


        /// <summary>
        ///  If AsyncStreamReader is active
        /// </summary>
        public bool Active { get; private set; }


        public void Start()
        {
            if (!Active)
            {
                Active = true;
                BeginReadAsync();
            }
        }


        public void Stop()
        {
            Active = false;
        }


        public AsyncStreamReader(StreamReader readerToBypass)
        {
            reader = readerToBypass;
            Active = false;
        }


        protected void BeginReadAsync()
        {
            if (Active)
            {
                reader.BaseStream.BeginRead(buffer, 0, buffer.Length, new AsyncCallback(ReadCallback), null);
            }
        }

        private void ReadCallback(IAsyncResult asyncResult)
        {
            int bytesRead = reader.BaseStream.EndRead(asyncResult);

            string data = null;

            //Terminate async processing if callback has no bytes
            if (bytesRead > 0)
            {
                data = reader.CurrentEncoding.GetString(buffer, 0, bytesRead);
            }
            else
            {
                //callback without data - stop async
                Active = false;
            }

            //Send data to event subscriber - null if no longer active
            if (DataReceived != null)
            {
                DataReceived.Invoke(this, data);
            }

            //Wait for more data from stream
            BeginReadAsync();
        }


    }
}

我使用以下命令来调用它：

logHandler.writeLogToBuffer();

uploadProcess.StartInfo.UseShellExecute = false;
uploadProcess.StartInfo.CreateNoWindow = true;            uploadProcess.StartInfo.RedirectStandardOutput = true;
uploadProcess.StartInfo.FileName = "rclone.exe";
uploadProcess.StartInfo.StandardOutputEncoding = Encoding.UTF8;
uploadProcess.StartInfo.Arguments =
                "sync -P " +
                "\"" + sourceDirectory + "\" " +
                "\"" + Properties.Settings.Default.remoteName + "/" + destination + "\" " +
                "--exclude '.*{/**,}' " +
                "--config \"" + Properties.Settings.Default.rcloneConfig + "\" " +
                Properties.Settings.Default.rcloneArgs;

uploadProcess.Start();

AsyncStreamReader stdOut = new AsyncStreamReader(uploadProcess.StandardOutput);
stdOut.DataReceived += (sender, data) =>
{
    if (!string.IsNullOrEmpty(data))
    {
        if (data.Contains("ETA"))
        {
            logHandler.loadLogFromBuffer();
        }
        logHandler.writeToLog(data);
    }
};
stdOut.Start();

然而，我遇到的问题是流的第一个字节(来自Transferring:...的T消息)与流的其余部分分开输出。

loghandler只是我编写的一个方法，用于在UI线程上写入WPF richtextbox。writeToLog(string message);只是将一行附加到RTB，writeLogToBuffer();将日志写到可以加载的缓冲区，以便用loadLogFromBuffer();加载RTB内容。

那么，这里的问题是什么呢？这是rclone的怪癖吗？我该如何着手解决这个问题？提前感谢！

Answer 1

您可以在进程中使用EnableRaisingEvents属性。将其设置为true并调用BeginOutputReadLine()方法以启动输出侦听。然后您就可以使用OutputDataReceived事件了。每当数据传入时，都会触发此事件。