Possible visual bug with RadGridView

[Nazario]

Dear telerik developers,
I have encountered a weird behavior in your RadGridView for wpf control. Whan SelectionMode is set to Extended and SelectionUnit is set to Cell, you have the feature to select many contiguous cells in drag-ish way (you click with the left button on a cell and drag over to another cell to have a square selection). The problem arises when you start dragging on a cell and move the mouse pointer over the header of the column: what you see is that all the upper cells get selected when the pointer get over every single them but when you reach the header the rows of the grid start scrolling down the view, as shown in the attached file. It happens also if you get over the group panel. You have to scroll with the mouse wheel to see the columns again if they went out of sight and when you resize the window the rows get back in the correct position.
Thanks

Warmest,
Nazario

 

[Dinko | Tech Support Engineer]

Hi Nazario,

Thank you for the provided image.

The described behavior seems to be described in this help article. May I ask you to try both suggestions and let me know if these black rows appear again?

Regards,
Dinko
Progress Telerik

[Nazario]

Hi Dinko,
I've already tried to set GroupRenderMode to Flat but it didn't changed the behavior. Neither solution 2 can apply because it also happens on RadGridViews that have no code-behind defined property on GridViewRows. Actually I don't think that the problem I'm experiencing is due to rows becoming blank (as in the help article you provided) but rather to still perfectly visible rows getting shifted downwards for some reason.
Thanks

[Dinko | Tech Support Engineer]

Hi Nazario,

Thank you for trying the approaches in the article. Still, it is strange that none of them works in your case. In the past, we have encountered this behavior with the blank rows, and we have made some changes in the virtualization mechanism of the control. Can you specify which version of our products you are using in your application? If it is an older version, can you try using the latest one (you can download it from your account) and check again if this behavior is still observable.

Regards,
Dinko
Progress Telerik

[Nazario]

Hi Dinko,
we are using version R2 2020 SP(2020.2.617.45), but as I've already mentioned I don't think the problem is about the rows getting blank but about the still visible rows getting shifted downwards and upward, possibly due to the grid being placed in a RadPane?
Thanks

[Dinko | Tech Support Engineer]

Hi Nazario,

Thank you for confirming the assembly version. Placing the control inside RadPane should not lead to such behavior. My guess here is that it comes from the drag-drop functionality. Can you share if you are using the logic implemented in this SDK example? If not, is it possible to isolate this behavior in a standalone project so that I can take a closer look? Also, can you check in your project if somehow duplicate rows are added to the control? Empty rows could appear when you have one object added multiple times.

Regards,
Dinko
Progress Telerik