Incrementing a label on a windows form

[Mo]

Hi,

I am reading a line off of a local file and using it to update records
on a database table. I am using a progress bar to show the progress
which is tied to the number of records inserted. I am trying to also
show in real time the count of the records which have been processed. I
havea label on the form and in the loop I have Label1.text =
i.ToString() where i is the loop counter.I am using a file watched to
trigger the process when the file is created in the directory. It might
be something to do with the asynchronousity of the process. Any ideas/

Thanks

 

[Andy]

If you're doing the work without using the BackgroundWorker component
(or a background thread, pre .Net 2) then your UI will not update while
you're running in the loop.

Use the BackGroundWorker, and have it raise ProgressChange events.

Andy

 

[Robert May]

Try Label1.Refresh().

However, if the label and the loop are not running in the same thread, you
may get an exception about unsafe updates and how you need to call invoke to
update the control.

For more details see:
http://msdn2.microsoft.com/en-us/library/system.windows.forms.control.invokerequired.aspx

Robert

 

[Stoitcho Goutsev \(100\)]

Mo,

What is the problem actually? I think it is that the lable doesn't update
while inside the loop.

If this is the case I can see two possible reasons. I also assume that you
use FileSystemWather compoenent for monitoring the file

1. You haven't set file watcher's SyncronizingObject - in this case the
events are fired in a worker thread and trying the change the text in the
label is wrong. Only the UI thread created the lable should alter the text

2. You have set file watcher's property and your code is executed by the UI
thread - in this case
when the program loops the application doesn't pump messages from the
message queue thus paint events are not precessed. The easiest solution is
to call Application.PreocessEvents periodically from inside the loop.