Scrollbar does not update on changing the scroll value

Question

When setting VerticalScroll.Value in a Panel with AutoScroll set to true, the scroll position changes accordingly but the

Answer 1

I ran into something nearly identical where I have a PictureBox (showing a graph) inside a panel with scroll bars, and I want to zoom in or out keeping the mouse-pointer position "apparently" stationary. Re-positioning the PictureBox inside the panel to do this throws off synchronization with the scroll bars, and thereafter, scrolling with the scroll bars will not show the full area of the PictureBox. The solution is to accomplish the move by assigning a computed value to the panel.HorizontalScroll.Value and/or panel.VerticalScroll.Value properties. But that alone isn't enough: one of these two solutions is required to make the application behave as designed:

1. KMan's solution above:

   panel.HorizontalScroll.Value = computed_value
   panel.PerformLayout()
   

2. Or JJMcLellan's solution above: in my case, assigning the computed value twice, e.g.:

   panel.HorizontalScroll.Value = computed_value
   panel.HorizontalScroll.Value = computed_value
   

Either one of these appears to have the same end results. Since #2 above makes it look like a bug, and #1 seems (hopefully) to be by design by Microsoft (?), I ended up using #1 in my application. I just wanted to confirm both these work in a VB.NET environment.