Zooming with GdViewerBox

[DriverTech]

Hello,

I need a simple code snippet that allows me to zoom in/out a displayed image when using the GdViewerBox in C#.

My library version is 9.4.0.12

I have tried the following:

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GdViewerBox.LockViewer = true;
GdViewerBox.Zoom = GdViewerBox.Zoom * 1.1;
GdViewerBox.ZoomIN(); // Tried both this and setting zoom individually
GdViewerBox.Invalidate(true);
GdViewerBox.Redraw();
GdViewerBox.Refresh();
GdViewerBox.LockViewer = false;

Nothing I do will update the zoom on the displayed image. These calls are in a method that is being invoked.

The best I could do was

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GdViewerBox.Zoom = GdViewerBox.Zoom * 1.1;

And then display a different image. The new image would take on the new zoom level.

Thanks for your help

Brendan

[SamiKharma]

Hi,

Please try taking out

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GdViewerBox.LockViewer = true;

and just call:

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ZoomIN()

Best,
Sami

[DriverTech]

Thank you for the reply. I tried this and it still does not zoom in at all. What is an appropriate zoom step for zooming 50%? Also, what should I set for ZoomMode on the GdViewerBox?

[SamiKharma]

Hi,

I am not sure what you are doing. Zooming works fine in the latest release. Please have a look at the VB.NET Image Processing Demo, it has a '+' button under the viewer, which basically calls the ZoomIN() function. If that does not work, please report back. If it does, then do something like it in your app.

Best,
Sami

[DriverTech]

I figured out how to make it work. After calling ZoomIn() I must then call GdViewer.DisplayFromGdPictureImage(ImagePath); so that it will draw the image again with the new zoom. This is very un-obvious and one would assume that simply calling GdViewer.Refresh() or Redraw() would handle this. Nowhere in the documentation does it specify that you must re display the image after calling ZoomIn().

[Loïc]

Hi,

Nowhere in the documentation does it specify that you must re display the image after calling ZoomIn().

This is normal since, of course, the image don't have to be reloaded from its source to apply any viewing operation.

My guess is you are closing the image before trying to zoom it...

Kind regards,

Loïc