How to move an image in the viewer

[louis]

Hi,

We need to display a picture and, above it, to draw any line, circle, ... But we need to erase a part of these lines, circles without changing the picture, like with an eraser.
So, we use a Cnt viewer with the picture and above it a normal Gd viewer (with the same dimensions) on which we draw the lines, ...

My question is : when zooming or scrolling the Cnt viewer, how to move the lines and circles in order to follow the cnt ? As the simple viewer is like a layer, we don't want to change its left or top property : it must be sized like the cnt viewer. And there is no method or property like "SetImageLeft".

I have seen in the forum a topic about the DrawImage property. But it seems we cannot put a negative value for nDstLeft for example.

Thanks in advance for your support.

Louis

[louis]

It seems that we can move the image as we want thanks to the properties SetHScrollBarPosition and SetVScrollBarPosition.
We have just to pay attention to the real size of the viewers (with/without border), the scrollbars, and of course the zoom value.
So, that works correctly now.

Louis

[Loïc]

Louis you are right !

SetHScrollBarPosition and SetVScrollBarPosition usage seems to be the best way to do that

With best regards,

Loïc