Hi
I tried your code...created a thread to spawn the process - still the
same - The standard output of the spawned process is available only
after the process has finished execution.
Since the called batch file is run in a different process, i guess we
need some kind of Interprocess communication (IPC) to send the output
of the spawned process to the calling process (my C# windows app).
Something like this -
----------------------
My App Spawned Process (batch file)
------- ----------------------------
Create Process ----------------------> Process Created
.. some processing...
.. some processing...
.. some output...
Receive Notification <------------------Send output text to 'My App'
Display in window ..some processing..
.. some processing...
.. some output...
Receive Notification <------------------Send output text to 'My App'
Display in window ..some processing..
.. some processing...
.. some output...
Receive Notification <------------------Send output text to 'My App'
Display in window ..some processing..
..Process Exit
Display Completed
But right now its happenning like this -
----------------------------------------
My App Spawned Process (batch file)
------- ----------------------------
Create Process ----------------------> Process Created
.. some processing...
.. some processing...
.. some output...(buffered ??)
..some processing..
.. some processing...
.. some output...(buffered ??)
.. some processing...
.. some output...(buffered ??)
..some processing..
..Process Exit
Read the output<--------------------- Send output text to 'My App'
Display the output
Display Completed
It would be great if yuu could throw some light on the internal working
of Process.start and how the output is made available to the calling
process and in what sequence.
Thanks
Vijay
Ignacio Machin ( .NET/ C# MVP ) wrote:
hi,
I would do several changes:
First of all I would run this in a worker thread ( I will assume this)
p.StartInfo.RedirectStandardOutput = true;
while((output = myStreamReader.ReadLine())!=null)
{
string[] args = new string[1];
string[0] = output;
this.txtOutput.Invoke( UpdateOutput, args );
}
void UpdateTXTBOX( string line)
{
this.txtbox.Text+=line;
}
these are the declarations
public delegate void EventString( string line);
public EventString UpdateOutput = new EventString ( UpdateTXTBOX);
With that it should work.
Also consider change from a Textbox to something else, the strings
operations may have a performance impact.
cheers,
--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
<vi*******@yahoo.com> wrote in message
news:11**********************@g43g2000cwa.googlegr oups.com... Hi
I created a windows app to run a dos batch file (which takes around
5mins to complete and generates lots of output messages on the console
in the meantime)and i used RedirectStandardOuput to display the output
text in a textbox.
The problem is that till the batch file has not finished running i
don't get to see the output in the text box!!
How do we trap the output and display as and when its generated by the
called app? can we get a LIVE UPDATE of the output?
Attached is part of the code for completeness :-
Your help will be greatly appreciated.
Thanks
Vijay
--------- CODE FOLLOWS -------------
// Create Process and Execute
p = new Process();
// Set Start Info
p.StartInfo.UseShellExecute = false;
p.StartInfo.CreateNoWindow=false;
p.StartInfo.RedirectStandardOutput = false;
p.StartInfo.FileName = cmd;
p.StartInfo.WorkingDirectory="C:\\xyz\\";
p.Start();
StreamReader myStreamReader = p.StandardOutput;
// Read the standard output of the spawned process.
while((output = myStreamReader.ReadLine())!=null)
{
this.txtOutput.Text += output + "\r\n";
}
p.Close();
