I decided to try and use a virtual listbox to get higher performance and lots of rows.
Unfortunately I found the vertical scrollbar basically positions itself ‘modulo 65536’.
Eg if there are 100,000 items and you drag the scrollbar to the bottom, the bottom most item is, roughly 34,465. Release the scrollbar and it jumps up, drag it slowly down and you will go past item 65536 and back to 1.
Clicking down works, and pressing end does go to the end.
Busted on every version of Delphi I’ve tried
Does anyone have a fix, workaround, or suggestion?
I don’t use Listboxes, but DevExpress cxGrids work fine with >6-figure row counts. I double checked on a DB table with ~330 K records using a cxGrid and it scrolls fine with dragging the scrollbar, page-up/down, and nav buttons. It is very zippy with no lag upon scrolling. It even does fast incremental searching on such a dataset.
I used a FireDAC query on a MySQL DB to populate the grid.
Yeah, I know DevExpress VCL is pricey but it has a lot to offer for the money..
