Problem with drawing lines on bitmap

[Janzki]

Hi,

Newbie here and in visual c++ programming :)

I have a problem prgramming an analog clock. It uses a transparent bitmap as a background (circular clockface) and filled polygons and lines as the clock hands.

The problem is that whenever the hands move they leave a "mark" behind. They just keep drawing new ones without erasing the older ones. How can I erase them? Refreshing maybe?

Don't know if this is enough info on the problem but thanks in advance.

-Janzki

[hvjahagirdar]

Use Invalidate() .

[Janzki]

I tried but ti get caught in a loop I guess beacause it shoot sthe PO to 100% straight away. Not sure if I'm doing it the proper way....

-Janzki

[ovidiucucu]

They just keep drawing new ones without erasing the older ones.
Possible, because you must also draw the background bitmap before clock hands.

I tried but ti get caught in a loop I guess beacause it shoot sthe PO to 100% straight away.
From where are you calling Invalidate()? From a loop? From the WM_PAINT message handler?

Set a timer (e.g. of one second time-out) value and call Invalidate() from WM_TIMER handler.

Just I can presume what you did wrong, because your question gives too few info.

Eventually, post the code here.

[Janzki]

Got it working.
It was a refresh issue.
Invalidate(); worked eventually :)

-Thanks