DoEvents

[danab]

I don't understand why one would use the DoEvents function.
How does it affect the application?

Thanks.
Dan.

[V(ery) Basic]

DoEvents lets the OS 'work' for a fraction of a second before returning to the procedure.

[kurtsimons]

I use it all the time

Lets say you have a long process that needs to run but your program is also monitoring a COMM port for incomming data, with out a doevents it the process loop (or multithreading the app) the incomming data will never be detected

It is also good for a stop button or anything to stop a certain sub or function.

Private Sub cmdstop_Click()
Do
DoEvents
Loop
End Sub

[kedaman]

Doevents will allow YOUR applications events to get fired.

DoEvents can prevent the OS from freezing by allowing it to process other events in it's queue

[kedaman]

Don't be so sure on that, Sam told me that it only concerns your applications events

[Nitro]

Originally posted by Matthew Gates
It is also good for a stop button or anything to stop a certain sub or function.

Private Sub cmdstop_Click()
Do
DoEvents
Loop
End Sub

This is a good skeleton to understand DOEVENTS.

[Sam Finch]

try something like this

Private Sub Command1_Click()
Dim x As Long
x = Timer
Do Until Timer > (x + 10)

Loop

MsgBox "Hello"
End Sub

Your App and the IDE will freeze for 10 seconds, but other processes will continue to function as normal. (unless you've been messin with thread priorities) All doevents does is check your own threads message queue and process any events such as command clicks, repainting and moving etc. without doevents your App apears to be frozen, but other processes keep going.

[Nitro]

Hello Sam


Danab, start a new project and drop a command button on the form.

Option Explicit
Private b_Cancel As Boolean

Private Sub Command1_Click()
  b_Cancel = True
End Sub

Private Sub Form_Click()
  b_Cancel = False
  Do While Not b_Cancel
    Me.BackColor = QBColor(Rnd * 10)
    DoEvents
  Loop
End Sub

Run the program. Click on the form and when you want to stop click on the command button.

[Edited by Nitro on 07-27-2000 at 09:31 PM]

[kedaman]

Hmm, what do you think guys? Isn't this a good progamming habit?

Do
  'Code
  doevents
Loop While Forms.count

[Sam Finch]

not really, it screws up unloading the form.

Originally posted by Nitro

This is a good skeleton to understand DOEVENTS.

What do you mean "skeleton"?

But actually, I like it because, well...explanation:

Do 'Do the process
DoEvents 'Just do nothing
Loop 'Loop it

So making it as a stop button will stop any events that are happening because it is doing the current code, but there is nothing to do actually so it just hangs there . Get what I mean?

[kedaman]

not really, it screws up unloading the form.

You didn't mean me right?= because it should prevent screwing up when unloading all forms

Matthew. DoEvents may seem like it does nothing, but in reality, it pauses execution for a fraction of a second so the OS can process other tasks.

[kedaman]

IN reality Doevents allows YOUR events to get fired, not allowing Other tasks getting processed, and that fraction of a second depends on what event's you get fired