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STOP a process in between .....

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Join Date: Jun 2007

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RahulV

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STOP a process in between .....

Feb 14th, 2009

hi,
i've created a Form1 which contains a long running process. But i want an feature that will help the user to stop the running process in between, when i click a Button or some other control.

How is it possible?

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RahulV

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Re: STOP a process in between .....

Feb 14th, 2009

Also the problem is that my Form1 which runs the process goes like disabled (automatically), ..... thats because, .... u can imagine because its a long process.

so im not able access the controls on the Form1.

PLS help !!!

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selvaganapathy selvaganapathy is offline

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Re: STOP a process in between .....

Feb 15th, 2009

Hi, use

DoEvents function so that other process get chance. This function helps to disable your form.

Example

 Help with Code Tags 
 VB Syntax (Toggle Plain Text) 
Dim bStop As Boolean
 
Private Sub cmdProcess_Click()
   Do While bStop <> True
      '
      '  Long Process
      '
      CurrentX = 0
      CurrentY = 0
      Cls
      Print Time
      DoEvents
   Loop
   bStop = False
End Sub
 
Private Sub cmdStop_Click()
   bStop = True
End Sub
Dim bStop As Boolean

Private Sub cmdProcess_Click()
   Do While bStop <> True
      '
      '  Long Process
      '
      CurrentX = 0
      CurrentY = 0
      Cls
      Print Time
      DoEvents
   Loop
   bStop = False
End Sub

Private Sub cmdStop_Click()
   bStop = True
End Sub

KSG

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Comatose

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Re: STOP a process in between .....

Feb 15th, 2009

If it is a system call (such as shell, or wsh.run) and it is blocking (ie, the program is waiting for shell or wsh.run to finish the externally running program), you need a much more complicated method involving things like waitforsingleobject...

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RahulV

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Re: STOP a process in between .....

Feb 16th, 2009

•

Originally Posted by selvaganapathy

Hi, use

DoEvents function so that other process get chance. This function helps to disable your form.

Example
Help with Code Tags

VB Syntax (Toggle Plain Text)
Dim bStop As Boolean
 
Private Sub cmdProcess_Click()
   Do While bStop <> True
      '
      '  Long Process
      '
      CurrentX = 0
      CurrentY = 0
      Cls
      Print Time
      DoEvents
   Loop
   bStop = False
End Sub
 
Private Sub cmdStop_Click()
   bStop = True
End Sub
Dim bStop As Boolean Private Sub cmdProcess_Click() Do While bStop <> True ' ' Long Process ' CurrentX = 0 CurrentY = 0 Cls Print Time DoEvents Loop bStop = False End Sub Private Sub cmdStop_Click() bStop = True End Sub

Sorry this did not work i told u that, mu Form1 gets disabled, thats normal when there's some long process is taking place. So im not getting access to the cmdButton (to click).

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RahulV

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Re: STOP a process in between .....

Feb 16th, 2009

•

Originally Posted by Comatose

If it is a system call (such as shell, or wsh.run) and it is blocking (ie, the program is waiting for shell or wsh.run to finish the externally running program), you need a much more complicated method involving things like waitforsingleobject...

Im not running any other program or shell.
Its just that the Form1 is processing a long process. Like suppose counting to 1000crores or more.

Last edited by RahulV; Feb 16th, 2009 at 2:58 pm.

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Comatose

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Re: STOP a process in between .....

Feb 16th, 2009

then doevents should work just fine.... somewhere when your form1 is doing processing... probably in some kind of do loop or while loop or for loop, simply stick a doevents.

 Help with Code Tags 
 vb Syntax (Toggle Plain Text) 
for i = 0 to 1000000
     retval = i * i
     doevents
next i
for i = 0 to 1000000
     retval = i * i
     doevents
next i

Last edited by Comatose; Feb 16th, 2009 at 3:53 pm.

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RahulV

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Re: STOP a process in between .....

Feb 18th, 2009

•

Originally Posted by Comatose

then doevents should work just fine.... somewhere when your form1 is doing processing... probably in some kind of do loop or while loop or for loop, simply stick a doevents.
Help with Code Tags

vb Syntax (Toggle Plain Text)
for i = 0 to 1000000
     retval = i * i
     doevents
next i
for i = 0 to 1000000 retval = i * i doevents next i

Sorry it did not work for me.....
Pls can anyone help me with this.

can creating thread help with this?

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Comatose

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Re: STOP a process in between .....

Feb 18th, 2009

I'm going to need to see your code then, in order to be able to troubleshoot this further.
You can not create a thread in Visual Basic 4/5/6. Doevents is only a partial fix to your problem. Doevents tells VB that a long ass loop is going on, and that it needs to do other stuff too, like handle mouse clicks. So, just for example, make a form and put 2 buttons on it....in button1, put this:

 Help with Code Tags 
 vb Syntax (Toggle Plain Text) 
while 1 = 1
     x = 200 * 200
wend
while 1 = 1
     x = 200 * 200
wend

Then, in button2, put this:

Help with Code Tags

vb Syntax (Toggle Plain Text)

end

Now run the code, and click button1. Now Try to click button2. Nice Huh? Now modify button1 to have this:

 Help with Code Tags 
 vb Syntax (Toggle Plain Text) 
while 1 = 1
     x = 200 * 200
     doevents
wend
while 1 = 1
     x = 200 * 200
     doevents
wend

Run the code, click button1, now click button2..... oh wow. Big difference.

Last edited by Comatose; Feb 18th, 2009 at 9:29 am.

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RahulV

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Re: STOP a process in between .....

#10

Feb 18th, 2009

@ Comatose

Okay!
that does work.

but in ur example u had written

Help with Code Tags

Visual Basic 4 / 5 / 6 Syntax (Toggle Plain Text)

End

statement for Button2 and that ends the whole program, instead i want to just end the running sub-procedure or the loop.

You have any other idea on this?