Excape Function

I have an application that is running and doing a bunch of calculations while running through a loop a specific number of times. RIght now when I hit the "GO" button it runs and I am forced to wait till the calculations are complete.

What I want to do is set a variable at the beginning of the loop that checks for a specific value. If True then it exits the code. Can I change that variable to True based off of a Keyboard entry. Say the user hits "Esc" on the next pass through the loop it would set the variable to True thus exiting the code.

Is there a Keyboard Buffer?
How do I access this Buffer to test for a specific value?

THanks in Advance

Heres what you can do...

Make a textbox that is off the screen, but it must be enabled, and be visable. We will call it txtbox.

before a loop takes place, set focus to the textbox:
txtbox.SetFocus

In the Txtbox event 'keydown' do an IF statement that detects the ESC key is pressed, and enter the command END into the statement results...



So, what we have is a textbox that recieves focus while a calculation is taking place, and it will terminate the program when the ESC key (ascii 27) is pressed.

This is un-proffesional and i'm not even sure if it will work, but keyboard buffers involve all sorts of API which I cant be arsed to go into.

This is a good idea and I can sort of get it to work. THe problem is that I have to have to cursor in the text box in order to get it to work.

While the code is running i hit the ESC key and nothing. Once the code stops I click in the text box and hit ESC and it works. THis is a bit confusing to me.

Note: I got rid of the End and just used a message box.

Private Sub txtbox_KeyDown(KeyCode As Integer, Shift As Integer)

If KeyCode = 27 Then
MsgBox "You are attempting to stop the code"
End If

End Sub

Is there something I am doing incorrectly.
The txtbox is visable and enabled
I am setting the Focus before the loop, and tested it in the loop.

Thanks for yor help

I had a similiar situation on a different program i was working on, Instead, put the code that needs to loop on the timer_tick sub, (make sure it's no longer a loop) and then keep a counter so it knows when to exit, and make sure it has to check that a boolean is true before it executes the code. Simply have a button on your form then that will turn the appropriate boolean to false and stop the timer. I found that setting the timer to tick every 200 ms. allows the system to interject commands but whatever code you have attached to the timer still runs nicely.

I am quite new to the VB world. I think I understand what you wrote but am still a bit confused on the actual code.

1. Call timer_tick Sub from within the Loop
2. Once in the Timer_tick Sub start a timer, Set a boolean to True or false.

If I stop the timer then does the code stops in the loop?

How do you set the Boolean based on a Keyboard entry?

THANK FOR YOU HELP HERE....IT IS APPRECIATED

Do you have a doEvents in the loop that does the calculating? If not, it may be the case that your txtbox doesn't get the message until the loop is done. Try that.