Keep form updated after switching windows?

[Al G]

Hi,

(VS2005, SP1, VB windows form)

I have a VB application that reads large files. While it is running, a
record counter is being updated and shown in a text box. If I switch to
another window, when I come back to the form, the text box is no longer
being updated. In fact the form seems frozen until the app ends. What am I
missing?

Al G

[Robin Tucker]

Re: Keep form updated after switching windows?

Hi Al,

You need to be reading your file on a separate thread. If you aren't, then
Windows Forms never gets a chance to handle events in it's message queue,
including the form or control "OnPaint" messages; at least for the duration
of the file operation. One possible solution is to use "DoEvents ()" inside
your file reading loop if you don't want to use threads but I would strongly
recommend against that as this is not a natural pattern for this kind of
task.


Robin

[Al G]

Re: Keep form updated after switching windows?

Thanks Robin, I'll try it.

Al G


"Robin Tucker" <rtgroups@hotma il.co.ukwrote in message
news:f1pqno$h7q $1$8300dec7@new s.demon.co.uk.. .

Hi Al,
>
You need to be reading your file on a separate thread. If you aren't,
then Windows Forms never gets a chance to handle events in it's message
queue, including the form or control "OnPaint" messages; at least for the
duration of the file operation. One possible solution is to use "DoEvents
()" inside your file reading loop if you don't want to use threads but I
would strongly recommend against that as this is not a natural pattern for
this kind of task.
>
>
Robin
>
>