Hi,

I am a beginner. I am drawing a sound waveform in a CScrollview derived view.
When I use the scroll bars, the drawing moves accordingly but in a persistent manner: All the previous plots stay on screen until their region gets invalidated.

When the whole view is invalidated, the original waveform gets redrawned in the original position relative to the view (device coordinates). It seems not to have noticed the fact that the scrolling bars are not at the same place anymore.

I have tried to use calls to OnPrepareDC and DPtoLP at various places in my code but until now nothing seems to change.

Can anybody give me some hints ?

Thank you very much