Scrolling listbox problem

[carloalto]

Hy everyone.
I have a listbox with about 100 elements. I use the vertical scroll bar.

Keyboard up arrow, down arrow, page up and page down works fine.
Whell on the mouse works fine.
If I use (left click on scroll bar up/down arrow) mouse to scroll up/down one position works fine.
Drag the handle of scroll bar works fine.

But paging with the mouse as it is now seems to have a problem with counting.
If you page down, then the item from the bottom will move to the top of the list.
Therefore, it is still visible. If you page up, then the item from the top will
not move to the bottom. It moves to the second invisible position.
If page up and page down would work as they should, then they will show the next
items wi
thout showing a single one again and without skipping a single item.
If you are on top of the list, then every page down shall show the next items
without skipping some. The same has to be for paging up from the bottom of the list.

i.e. the items are the numbers 0,1,2,3,....99
If the size of listbox has 8 places and the actual windows displays 20,21,22,23,24,25,26,27
after the mouse page up the windows will display 11,12,13,14,15,16,17,18 not
13,14,15,16,17,18,19,20 as Keyboard page up.

Follows the files to build a sample to test


I use LabWindows CVI 6.0

Thank in advance.

[Richard H.]

Hi carloalto,

I could reproduce this in CVI 7.0 exactly the way you described it.
(BTW: this would have been a bit easier if you would have included the test.h file.)

I will send this to R&D and hope they will improve it in a future version of CVI.

Regards,
Richard H.
National Instruments