How to terminate or exit a for loop when the user clicks on stop button

Question

Actually my problem is to stop a loop when i click on stop button.
example:i have two buttons 'start' and 'stop'
in start buttom i wrote a for loop as

dim i as integer
For i=1 To 100000
print i
Next

when i click on start buuton it prints 'i' value up tp 100000.

my question is when i click on 'Stop' button the for loop has to terminate or Exit from the  loop and should stops the execution.
Is it possible to termianate or Exit the 'for loop'

---

PS.Shakeer Hussain Hyderabad

Answer 1

Actually my problem is to stop a loop when i click on stop button.
example:i have two buttons 'start' and 'stop'
in start buttom i wrote a for loop as

dim i as integer
For i=1 To 100000
print i
Next

when i click on start buuton it prints 'i' value up tp 100000.

my question is when i click on 'Stop' button the for loop has to terminate or Exit from the  loop and should stops the execution.
Is it possible to termianate or Exit the 'for loop'

---

PS.Shakeer Hussain Hyderabad

Answer 2

Create a boolean variable, inside your cancel button, set cancel=true

dim cancel as boolean=False

For i =1 to 100000
if cancel=true
exit for
end if
print i
Next

vb6 forum : http://www.vbforums.com/forumdisplay.php?forumid=1

kaymaf

---

CODE CONVERTER SITE

http://www.carlosag.net/Tools/CodeTranslator/.

http://www.developerfusion.com/tools/convert/csharp-to-vb/.

Answer 3

Double post, this is your previous thread on the same issue
http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/e7e2cd73-e547-46d8-b1b2-36f839e6ecf0

kaymaf

---

CODE CONVERTER SITE

http://www.carlosag.net/Tools/CodeTranslator/.

http://www.developerfusion.com/tools/convert/csharp-to-vb/.

Answer 4

Hi kaymaf,
In the same way,i want exit in while loop.
How plz write a sample code

---

PS.Shakeer Hussain Hyderabad

Answer 5

Public Class Form1
    Dim continueLooping As Boolean = True
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        continueLooping = False
    End Sub

    Private Sub LoopMethod()
        Dim i As Integer = 0
        While (Me.continueLooping)
            i += 1
            Print(i)
            If (i = 100000) Then
                Me.continueLooping = False
            End If
        End While
    End Sub
End Class

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 6

Try this
Dim i As Integer
Dim cancel as Boolean=False
Do Until i < 100000
    i = i + 1
 Print i
if cancel=true
Exit Do
 End if
Loop 

Take look at this link for vb6 loop
http://www.vb6.us/tutorials/understanding-do-and-while-loops

Also, this is VB.NET forum which does not support VB6. For Vb6 issue, you can try this link below

vb6 forum : http://www.vbforums.com/forumdisplay.php?forumid=1

kaymaf

---

CODE CONVERTER SITE

http://www.carlosag.net/Tools/CodeTranslator/.

http://www.developerfusion.com/tools/convert/csharp-to-vb/.

Answer 7

Hi kaymaf and Rudedog2
I tested you code by taking two buttons start and stop.

when i click on 'start' buttin to start a loop it executing a loop.when i try to terminate or stop a loop by clicking on 'stop' button,the stop button does not take any action or click event untill the loop completly executed.

plz test it.you will get idea about it.

waitng for you reply

---

PS.Shakeer Hussain Hyderabad

Answer 8

Add this line inside of the loops.

Application.DoEvents.

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 9

Hi Rudedog2

you had solved my problem
VERY VERY VERY VERY Thank you.
IS Application.DoEvents  will works in vb6.0 or not.i test above code in vb.net,it is woking.

Actually in my project(win form-start Scan button) i have while loop.in while loop i had written a code to SCAN an object in X-Axis,Y-Axis and Theta Aixs.while we kept in scan mode it scans every particle in 3 directions, i am using while loop.it takes 2 to 3 days to complete a SCAN of an object.in the middle user clicks on 'stop scan' button,the while loop has to terminate and stop the scan. 

and one more thing during this process in while loop,while the user minimizing the form and opened another programme or word document the win form will stuck or hangs.

How to avoid without hanging a win-form and user can open any programme normally.
waiting for your reply

And also thanks to Kaymaf

---

PS.Shakeer Hussain Hyderabad

Answer 10

vb6 forum : http://www.vbforums.com/forumdisplay.php?forumid=1

kaymaf

---

That guy's wise.

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 11

and one more thing during this process in while loop,while the user minimizing the form and opened another programme or word document the win form will stuck or hangs.

How to avoid without hanging a win-form and user can open any programme normally.
waiting for your reply

And also thanks to Kaymaf

---

PS.Shakeer Hussain Hyderabad

You really need to throw that entire process into a background worker (which is what I would have suggested to start with even with your original question).

Give it some thought. The background worker can be daunting at first but for *most* things that you'll use it for, it's really not all that difficult.

Good luck :)

Answer 12

Background Worker.  Take a look at this thread.

how to add a progress bar in visual studio 2005/2008 (vb.net) when ...

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 13

vb6 forum : http://www.vbforums.com/forumdisplay.php?forumid=1

kaymaf

---

That guy's wise.

---

Mark the best replies as answers. "Fooling computers since 1971."

Oh, he's using VB6?

I didn't pick up on that - I'm out of my element then. :-o

Answer 14

Hi Smith,
First my importance is ,i need a code to terminate a while loop.

seocnd importance  is hanging a from.

if we post  a question step by step then it is easy to understand to me and others also.

---

PS.Shakeer Hussain Hyderabad

Answer 15

Also, this is VB.NET forum which does not support VB6. For Vb6 issue, you can try this link below

vb6 forum : http://www.vbforums.com/forumdisplay.php?forumid=1

kaymaf.  That guy's wise.

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 16

If you're using VB6 then I'm sorry to say that I can't help. This forum is about VB.NET and I honestly don't know the differences but I understand they're a good bit different.

Answer 17

Hi

just let me know Application.DoEvents will works or not in VB6.

if not works in VB6 then what code i have to write instead of writtng Application.DoEvents

Plz help it.......Its important for me.....

---

PS.Shakeer Hussain Hyderabad

Answer 18

Hi Smith,
First my importance is ,i need a code to terminate a while loop.

seocnd importance  is hanging a from.

if we post  a question step by step then it is easy to understand to me and others also.

---

PS.Shakeer Hussain Hyderabad

The command I gave for .NET has the same name as the one in VB6, DoEvents.

What is DoEvents?

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 19

Hi Rudedog2
Thank you very much,you saved me.

Plz give me solution for avoiding a win-from  stuck or hanging.

Why its happening like that.This is my biggest bug in my project..
waiting for reply

---

PS.Shakeer Hussain Hyderabad

Answer 20

If you're using VB6 then I'm sorry to say that I can't help. This forum is about VB.NET and I honestly don't know the differences but I understand they're a good bit different.

Yes, I think he was already pointed to the VB 6.0 link in another thread.

In any event (no pun intended), he can use DoEvents, a Timer or the GetQueueStatus API function call so that the Stop button Click event can be processed and the loop terminated.

---

Paul ~~~~ Microsoft MVP (Visual Basic)

Answer 21

Hi Rudedog2
Background Worker.  Take a look at this thread.

how to add a progress bar in visual studio 2005/2008 (vb.net) when ... 

--------------------------------------------------------------------------------

I saw above thread.can i use the same code in vb6.
there are so many responses.which response code i have to use.

---

PS.Shakeer Hussain Hyderabad

Answer 22

The command I gave for .NET has the same name as the one in VB6, DoEvents.

What is DoEvents?

This time, take a look at the link.

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 23

Not about Doevents.

about the Link<a>how to add a progress bar in visual studio 2005/2008 (vb.net) when ... </a>

---

PS.Shakeer Hussain Hyderabad

Answer 24

There are complete examples of adding a ProgressBar and a Label to Windows Form that are updated by a BackgroundWorker at the link, written in VB, C#, and C++.  What more do you want?  If you want me to write an example, I won't.  I already wrote up 3 examples that thoroughly demonstrate how to use a BackgroundWorker. 

This forum is not for VB6.  Stop asking for VB.NET solutions, then asking for a translation to VB6.  You have been directed where to go for the help that you seek.

Happy Coding.

 

---

Mark the best replies as answers. "Fooling computers since 1971."

Answer 25

I am unable to stop the loop and application not at all allowing to Press the Stop button.

It seems like Hung, any advise ?

Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        btnStop.Enabled = True
        btnSelectFile.Enabled = False
        btnStart.Enabled = False
        btnStop.Focus()

        Dim strFileName As String = txtFileName.Text.ToString
        Dim strLineText As String

        If System.IO.File.Exists(strFileName) = True Then
            Dim objReader As New System.IO.StreamReader(strFileName)

            While objReader.Peek() <> -1 And stopclick = False

                strLineText = objReader.ReadLine()
                MsgBox(strLineText, MsgBoxStyle.Information)
                Application.DoEvents()
                Thread.Sleep(My.Settings("strDelay") * 1000)
                'System.Diagnostics.Process.Start(My.Settings("strFireFoxLocation"), strLineText)


            End While


        End If
    End Sub


    Private Sub btnStop_Click(sender As Object, e As EventArgs) Handles btnStop.Click
        stopclick = True
        btnSelectFile.Enabled = True
        btnStart.Enabled = True
        btnStop.Enabled = False
    End Sub

---

Raman Katwal


Please remember to mark the replies as answers if they help and unmark them if they provide no help

Answer 26

Simple and exactly what I was looking for. Thank you!