MouseWhell zoom or scroll about cyotek.windows.forms.imagebox

[cyotek]

Hello, and thanks for the question. I took a quick look at this, and found it reasonable easy to do by overriding OnMouseWheel. There is a caveat though - the MouseWheel event will no longer be raised unless Control is held.

You can find my implementation below - I check to see if Control is pressed and if so, use the default implementation. If it isn't pressed, I then check to see if a vertical scrollbar is present, and if so get the current AutoScrollPosition property value, offset it by the wheel delta (making sure it doesn't fall out of the boundaries of the scrollbar), and then re-apply it. Seems to work fine - you could adapt the code to scroll horizontally instead of vertically, or to scroll horizontally if a vertical scrollbar isn't present.

protected override void OnMouseWheel(MouseEventArgs e)
{
  if ((Control.ModifierKeys & Keys.Control) != 0)
  {
    base.OnMouseWheel(e);
  }
  else if (this.VScroll)
  {
    Point position;
    int value;

    position = this.AutoScrollPosition;

    value = Math.Min(Math.Max(-position.Y - e.Delta, 0), this.VerticalScroll.Maximum);

    this.AutoScrollPosition = new Point(-position.X, value);
  }
}

Hope this information helps!

Regards;
Richard Moss

[fabiencomte]

I will try that asap.
Thank you for your help.