One of the forms in my C# .NET application has multiple DataGridViews that implement drag and drop to move the rows around. The drag and drop mostly works right, but I've been having a hard time getting the DataGridViews to AutoScroll - when a row is dragged near the top or bottom of the box, to scroll it in that direction.

So far, I've tried implementing a version of this solution. I have a ScrollingGridView class inheriting from DataGridView that implements the described timer, and according to the debugger, the timer is firing appropriately, but the timer code:

SendMessage(Handle, WM_VSCROLL, (IntPtr)scrollDirectionInt, IntPtr.Zero);

doesn't do anything as far as I can tell, possibly because I have multiple DataGridViews in the form. I also tried modifying the AutoScrollOffset property, but that didn't do anything either. Investigation of the DataGridView and ScrollBar classes doesn't seem to suggest any other commands or functions that will actually make the DataGridView scroll. Can anyone help me with a function that will actually scroll the DataGridView, or some other way to solve the problem?