Last Updated: 14 Dec 2020 19:28 by James Lett
James Lett
Created on: 14 Dec 2020 17:58
Category: Grid
Type: Bug Report
Under Edge, with the "Microsoft Edge scrolling personality" flag enabled, on a 4k monitor and 200% DPI, Virtualized scrolling doesn't always trigger OnRead event and shows placeholders



I am using a Blazor TelerikGrid component with Virtual ScrollMode.  I have set a fixed Height, PageSize that exceeds the rows that fit in the grid, and a RowHeight which I have confirmed fits the row contents and resolves to a computed Height of the same value (using Chrome Dev Tools -> Computed tab).  Everything works fine except that sometimes scrolling does not trigger the OnRead event and the rows displayed after scrolling are placeholders. 

I don't experience this problem when I click the scroll arrow buttons (up or down).  I don't experience the problem at all if I drag the scroll bar up or down.  But if I page up/down, or click on the scroll page area up/down it will sometimes work and sometimes not.  If placeholders are shown, I only need to click a scroll button up/down a few times for it to then read and display the correct rows.

To reproduce use the attached VS2019 project, click "Telerik Scroll Issue" nav menu, and in the TelerikGrid click the page down areas of the vertical scrollbar 3 times.



The bug is only reproducible with 4k monitor and 200% DPI on Edge Chromium. Also when the "Microsoft Edge scrolling personality" flag from edge://flags/ is disabled, there is no problem.



Attached Files:
1 comment
James Lett
Posted on: 14 Dec 2020 19:28

Just to clarify;

  • Issue only occurs when scale/DPI is higher than 100%
  • Issue occurs on both Chrome and Edge Chromium (when DPI is higher than 100%), but harder to reproduce on Chrome
  • Issue occurs on Edge Chromium when "...scrolling personality" is disabled, but harder to reproduce