External program run delay 1

[kokon]

Hi, when I start from application my external program (execution takes 4 min) it wait until my external program exit, then i see my application window with textbox with the external program output. How to make textbox update in real time. source:

---------
Process myProcess = new Process();
ProcessStartInfo myProcessStartInfo = new ProcessStartInfo("text.exe");
myProcessStartInfo.UseShellExecute = false;
myProcessStartInfo.RedirectStandardOutput = true;
myProcess.StartInfo = myProcessStartInfo;
myProcessStartInfo.WindowStyle = ProcessWindowStyle.Hidden;
myProcessStartInfo.CreateNoWindow = true;

myProcess.Start();

StreamReader myStreamReader = myProcess.StandardOutput;
// Read the standard output of the spawned process.
string myString = myStreamReader.ReadToEnd();
Console.WriteLine(myString);
richTextBox1.Text = myString;
myProcess.Close();

-----------------------
thx for help

 

[JurkMonkey]

myStreamReader.ReadToEnd(); will cause your app to wait until the program exits.

if you loop through the output as it is streaming you can update your textbox in "real time"

string myString = myStreamReader.Read();

while (myString != null)
{
richTextBox1.Text += myString + System.Environment.NewLine();

myString = myStreamReader.Read();
}

 

[kokon]

sorry but it is not working, i have tried to write whole code inside new thread but it doesnt help. Any idea?

 

[serializer]

I could not sleep and decided to solve this for you. I have created a project in VS2005 which lies here. Remember to change the exe that should be started in the cAppStart class. You can download the solution here:

http://neteject.com/realtimeoutput.zip

Basicly I have this class which starts the process and raise an event when output is read:

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.IO;

namespace WindowsApplication3
{
class cAppThread
{
public delegate void DelegateOutputReceived(string output);
public static event DelegateOutputReceived OnOutputReceived;
public void Run()
{
string output = null;
Process myProcess = new Process();
ProcessStartInfo myProcessStartInfo = new ProcessStartInfo("c:/outputtest.exe");
myProcessStartInfo.UseShellExecute = false;
myProcessStartInfo.RedirectStandardOutput = true;
myProcess.StartInfo = myProcessStartInfo;
myProcessStartInfo.WindowStyle = ProcessWindowStyle.Hidden;
myProcessStartInfo.CreateNoWindow = true;
myProcess.Start();
StreamReader myStreamReader = myProcess.StandardOutput;
string myString = myStreamReader.ReadLine();

while (myString != null)
{
output += myString + System.Environment.NewLine;
myString = myStreamReader.ReadLine();
OnOutputReceived(output);
}
}
}
}

The class is started in a new thread here:

private void StartApp()
{
cAppThread.OnOutputReceived += new cAppThread.DelegateOutputReceived(OutPutReceived);
cAppThread at = new cAppThread();
Thread t = new Thread(new ThreadStart(at.Run));
t.IsBackground = true;
t.Start();
}

The function that handles the event is here:

void OutPutReceived(string output)
{
if (InvokeRequired)
{
object[] obj = new object[1];
obj[0] = output;
cAppThread.DelegateOutputReceived del = new cAppThread.DelegateOutputReceived(OutPutReceived);
this.BeginInvoke(del, obj);
}
else
{
richTextBox1.Text = output;
}

}

 

[serializer]

Now it is time to sleep - good night! =)

 

[serializer]

By the way, it was tested against the following console app code:

static void Main(string[] args)
{
for (int i = 0; i < 30; i++)
{
Console.WriteLine(i);
System.Threading.Thread.Sleep(1000);
}
}

It requires that there is a new line after each output - otherwise the code has to be slight changed.

 

[kokon]

Thx for your help and sorry about sleepless night By the way, your code is going to slow down when the external program generates really big output... any ideas? Once again thx for help, and i`m looking forward for your reply...

 

[serializer]

Well, it is probably GUI that takes most CPU/slows down. So I recommend that you use a grid instead or listview. Also, you should limit that listview or grid to a number of lines so that it wont get too big.