C＃将运行流程标准化

Question

I have an app that runs a background process and I need to show that app's standard out during execution, like real time. I tried process.OutputDataReceived but it triggered after background process terminated itself. But I need to show standard output when that out is created by the process.

FYI: I redirected standard output and set UseShellExecute false

Here is full changes I did to the process:

ProcessStartInfo t = new ProcessStartInfo();
t.CreateNoWindow = true;
t.FileName = name;
t.Arguments = args;
t.UseShellExecute = false;
t.CreateNoWindow = true;
t.RedirectStandardOutput = true;
t.RedirectStandardError = true;

Process p = new Process();
p.StartInfo = t;
p.OutputDataReceived += P_OutputDataReceived;
p.Start();
p.BeginOutputReadLine();

And my event:

private void P_OutputDataReceived(object sender, DataReceivedEventArgs e)
    {
        Textbox1.Text = e.Data;
    }

Also I tried this with a python file, an executable version of it, and a C files executable, but same result at all of them.

Edit: I tried this solution but got the same result again

**Update 04.06.2018: **I just found that the P_OutputDataReceived event is also triggeredn when app waits for standart input, but still cannot found a way to trigger that event in real-time

Answer 1

As the executed process is also a different thread, you need to return to the UI thread for displaying data from that process. This can be achieved with the Invoke method as shown below:

private delegate void ShowDataDelegate(string data);

private void P_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
   ShowDataDelegate showDataDelegate = new ShowDataDelegate(ShowData);
   Invoke(showDataDelegate, e.Data);
}

private void ShowData(string data)
{
   textBox1.Text = data;
}

Answer 2

My first answer was wrong and useless. Sorry about that. This is a Windows Forms example for how to invoke the application (Robocopy.exe) with a button press and redirect the output to a TextBox on the main form in real time.

using System;
using System.Diagnostics;
using System.Windows.Forms;

namespace testApp
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            using (Process tProc = new Process())
            {
                ProcessStartInfo t = new ProcessStartInfo();
                t.CreateNoWindow = true;
                t.FileName = Environment.SystemDirectory + "\\robocopy.exe";
                t.Arguments = "/?";
                t.UseShellExecute = false;
                t.CreateNoWindow = true;
                t.RedirectStandardOutput = true;
                t.RedirectStandardError = true;

                Process p = new Process();
                p.StartInfo = t;
                p.OutputDataReceived += new DataReceivedEventHandler(P_OutputDataReceived);
                p.Start();
                p.BeginOutputReadLine();                  
            }
        }

        private void P_OutputDataReceived(object sender, DataReceivedEventArgs e)
        {
            try
            {
                Trace.WriteLine(e.Data);
                this.BeginInvoke(new MethodInvoker(() =>
                {
                    textBox1.AppendText(e.Data ?? string.Empty);
                }));
            }
            catch (System.Exception x)
            {
                MessageBox.Show(x.ToString());
            }
        }
    }
}