Closing a form in a clean way
Hi ,
I have a simple but still critical issue
I have a windows application in VB.net where a quite time consuming operation will happen in the click of a button .
I need to have the following
1) Have the form in the responding state ( The user should be able to click an Abort button to close the application at any time)
2) When the Abort button is clicked , the application should exit (FROM TASK MANAGER ALSO)
I used Application.DoEvents() to keep the form responsive . But then the application, when aborted is not exiting from Taskmanager
My TestCode will have just two buttons 1)WasteTime 2) Abort
On the Click of the WasteTime button , the following routine runs
'' This mimics a time consuming operation
Sub WastingTime()
Dim i, j, k As Integer
For i = 0 To 10000
For j = 0 To 10000
For k = 1 To 10000
'' Application.DoEvents() '' THIS CREATES PROBLEM AND IS COMMENTED
Next
Next
Next
End Sub
Can you please help me to make this a responsive but still abortable form , when a time consuming operation is on
Thanks
Sam
I have a simple but still critical issue
I have a windows application in VB.net where a quite time consuming operation will happen in the click of a button .
I need to have the following
1) Have the form in the responding state ( The user should be able to click an Abort button to close the application at any time)
2) When the Abort button is clicked , the application should exit (FROM TASK MANAGER ALSO)
I used Application.DoEvents() to keep the form responsive . But then the application, when aborted is not exiting from Taskmanager
My TestCode will have just two buttons 1)WasteTime 2) Abort
On the Click of the WasteTime button , the following routine runs
'' This mimics a time consuming operation
Sub WastingTime()
Dim i, j, k As Integer
For i = 0 To 10000
For j = 0 To 10000
For k = 1 To 10000
'' Application.DoEvents() '' THIS CREATES PROBLEM AND IS COMMENTED
Next
Next
Next
End Sub
Can you please help me to make this a responsive but still abortable form , when a time consuming operation is on
Thanks
Sam
ASKER CERTIFIED SOLUTION
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Guy's answer is the way to go, but there might be more at stake, depending on your application.
Application.DoEvents enable the Click on your Abort button. But I would not call it in every loop, because it slows down things a lot because you are interrupting the code on each loop. Put a counter in the loop and call DoEvents only from time to time.
Then, the code in your Abort button is important. Not only should it deal with the Boolean variables proposed by Guy, but it also need to properly close the application. The best way to do it is Application.Exit. This will trigger the FormClosing event on all the currently loaded forms. Depending on how the application is structured, a Form that is still in memory but invisible can sometimes hold the application so that it still show as a process in the Task Manager.
Application.DoEvents enable the Click on your Abort button. But I would not call it in every loop, because it slows down things a lot because you are interrupting the code on each loop. Put a counter in the loop and call DoEvents only from time to time.
Then, the code in your Abort button is important. Not only should it deal with the Boolean variables proposed by Guy, but it also need to properly close the application. The best way to do it is Application.Exit. This will trigger the FormClosing event on all the currently loaded forms. Depending on how the application is structured, a Form that is still in memory but invisible can sometimes hold the application so that it still show as a process in the Task Manager.
ASKER
Thanks James. Indeed a really useful tip
ASKER