APITimer control 2.0

[joaquim]

every professional programmer said that the VB6 timer control isn't "good"(i don't know the right term) for the programs.
is why that i build these control
is very easy to use... like VB6 timer control... or more easy
i accept comments, please

[LaVolpe]

Here are some comments.

1. API timers do have advantages over VB timers. API timers can be windowless and the timer interval can be very large. VB timers are not windowless and max interval is a little over a minute.

2. I would recommend you make your timer windowless too. You are creating timers in the code using hWnd of zero. If you keep your usercontrol windowed, then you should create your timer with the usercontrol's hWnd in my opinion. By assigning the timer a non-zero hWnd, the timer is automatically destroyed when the hWnd is destroyed. However, you are using the usercontrol's hWnd to send it messages, so making it windowless would require rethinking that logic.

3. Your event is called Cicle. Is that word English? If so, it is misspelled and should be Cycle.

4. The Interval property should do more than just save a value. If user passes 0 then the timer should stop if it is running. If user passes > 0 then the timer should stop/restart with new interval if already running or it should start if it is currently stopped. That is how the VB timer works.

5. A major flaw with your logic. If more than one timer control is in use, only one will receive events. This is because your module is sending a message to the control that matches the MouseOverControl value in your bas module. Public variables/values in a bas modules within a usercontrol are shared among all instances of that usercontrol.

However, in order to make your control work correctly, you would need to modify some code to allow multiple timers to call the correct usercontrol. This fix requires the timer control to stay windowed and not windowless.

1. In the usercontrol, always use the usercontrol's hWnd with SetTimer and KillTimer.
Do not use zero as the hWnd

' Example
lTimerId = SetTimer(UserControl.hWnd, 100&, ByVal Interval, AddressOf TimerRoutine)
' Example
KillTimer UserControl.hWnd, lTimerID

2. In the bas module

 change from: SendMessage MouseOverControl, WM_KEYDOWN, 1000, 0
change to: SendMessage lHwnd, WM_KEYDOWN, 1000, 0

3. You can now remove the MouseOverControl variable from your bas module and usercontrol.

[joaquim]

hi LaVolte
i belive that i did what you said
thanks for the help my friend

[LaVolpe]

Here are some more comments, you may want to test it some more

1. When interval is set to zero during design time and the TimerState is set to Started, the timer will fire when the project is run. This is because in your TimerState routine, you create the timer with an interval of zero when TimerState=TimerStart. On Win9x machines (i.e., 95/98/ME) that may turn the timer off or fail to create the timer. But on NT-based systems, the timer will automatically be set to USER_TIMER_MINIMUM which I believe is 10ms. Try it. So, I think you want to test the interval is > 0 before actually creating the timer.

2. I was mistaken earlier when I said then when an active timer's interval changes, the timer is stopped then restarted with the new interval. Testing VB's timer, VB does not do that. VB simply calls SetTimer again and in this case if the timer id does not change:

When SetTimer replaces a timer, the timer is reset. Therefore, a message will be sent after the current time-out value elapses, but the previously set time-out value is ignored.

In other words if the interval was 5 seconds, and the interval is changed, before the 5 seconds happens, to say 30 seconds, what happens? When the prior interval of 5 seconds elapses, no event is fired. When the current interval elapses, 30 seconds, an event is fired.
MSDN SetTimer source documentation

Well your code doesn't quite do that and it is really up to you how you want to handle that scenario. Currently your interval does not change because you do not call the TimerState routine again from the Interval routine when lngInterval > 0.

[joaquim]

Here are some more comments, you may want to test it some more

1. When interval is set to zero during design time and the TimerState is set to Started, the timer will fire when the project is run. This is because in your TimerState routine, you create the timer with an interval of zero when TimerState=TimerStart. On Win9x machines (i.e., 95/98/ME) that may turn the timer off or fail to create the timer. But on NT-based systems, the timer will automatically be set to USER_TIMER_MINIMUM which I believe is 10ms. Try it. So, I think you want to test the interval is > 0 before actually creating the timer.

2. I was mistaken earlier when I said then when an active timer's interval changes, the timer is stopped then restarted with the new interval. Testing VB's timer, VB does not do that. VB simply calls SetTimer again and in this case if the timer id does not change:

In other words if the interval was 5 seconds, and the interval is changed, before the 5 seconds happens, to say 30 seconds, what happens? When the prior interval of 5 seconds elapses, no event is fired. When the current interval elapses, 30 seconds, an event is fired.
MSDN SetTimer source documentation

Well your code doesn't quite do that and it is really up to you how you want to handle that scenario. Currently your interval does not change because you do not call the TimerState routine again from the Interval routine when lngInterval > 0.

thanks for that information my friend
i will change that
thanks

[Merri]

This may interest you: SelfTimer.

[joaquim]

finally i build a new APITimer version: APITimer 2.
finally these control is:
- compatible with Visual basic 6 timer control(you can change the timer without any code change);
-and now i put 1 precise property for these timer be more precise.
i acept comments and sugestions