Scrolling slow and jerky in RadListView and RadDataGrid

[Nik]

Hello Support,

We are using RadListView and RadDataGrid controls in our UWP and iOS applications. On these controls we observed there is a lag when we scroll fast, this lag is with the control's default scroll  Please see attached video (UWP_without_scrollview.mp4 and iOS_without_scrollview.mp4) for our UWP and iOS applications, you will see the white space when scrolling very fast.   

Further, we tried adding Xamarin's ScrollView over the RadListView and RadDataGrid controls, with this we do not see the lag when scrolling fast (see attached video UWP_with_scrollview.mp4 and iOS_with_scrollview.mp4).

In the documention for the RadListView and RadDataGrid controls, (refernce https://docs.telerik.com/devtools/xamarin/controls/listview/listview-getting-started#:~:text=Telerik.XamarinForms.DataControls%22-,WARNING,-%3A%20RadListView%20control%20provides), it is mentioned that if we add Scrollview to these controls, it would have issue withe the UI Virtulization or Gesture Mechanism. Kindly let us know if can continue using Xamarian ScrollView with the RadListView and RadDataGrid controls?

Also please let us know if there is any other way to get around the lagging issue with using the the RadListView and RadDataGrid default Scroll.

[Nik]

Hello Team,

Awaiting your response on the above issue.

Please let us know, if there is any way to get around the  lagging issue when scrolling fast with the RadListView and RadDataGrid default Scroll.

[Didi]

Hi Nikhil,

Thank you for the provided videos.

The behavior may occur because of the customizations made. You use template columns in the Grid. From the videos I assume the control is RadDataGrid? The cells and rows are recycled and reused for the new rows/cells.

I have tested our sample examples on iOS and UWP and cannot reproduce slow and jerky scrolling on iOS and on UWP (using the mouse wheel on UWP). If you use the Scrollbar on UWP, then the behavior is expected. Test with the mouse wheel. 

Regarding to the ScrollView usage - DataGrid and ListView controls has internal scrolling, so positioning the controls inside a ScrollView is not recommended. For example you cannot scroll to the last item, when having more elements inside the main ScrollView, the DataGrid cannot be scrolled, etc. 

Regards,
Didi
Progress Telerik

[Nik]

Hi Didi,

Thank you for your response.

We are using the template columns in the RadDataGrid control. As per our requirement we need to display images and data in the cell/columns and hence have used template column. Is there any other way to customize the column in RadDataGrid control without using template columns, then please suggest.

Regarding using mouse wheel and not using the Scrollbar, unfortunately we cannot restrict the users from not using the Scrollbar as that's the very basic and common thing any user/layman would use to scroll. Kindly let us know if there is any other property of the RadDataGrid control that could be used to avoid the lag when scrolling fast.

Further, we ran Telerik's sample code and it too has the same behavior i.e. the scroll is slow and jerky. We download the sample code from github (https://github.com/telerik/telerik-xamarin-forms-samples) . Run the UWP application.
In your sample application, you too have used template columns for customization. As you mentioned that template columns are causing the slowness, please suggest alternative for customizing columns in the grid.

[Nik]

Hi Didi,

As mentioned in our above comment, with Telerik's sample too we see the same behaviour with RadListGrid control, when using the scroll bar. Please see the attached video

In our project we are also using RadListView control on other screen. The RadListView control is lagging when using Scroll Bar. Can you please let us know if there is any setting in RadListView that we can use to avoid the lag. Please see attached video showing the lag using the RadListView Control.

[Didi]

Hi Nikhil,

Yes, I tested the scenario and reproduced the behavior. It occurs only when the scrollbar is used. As I explained the behavior comes from the usage of Template column, and I do not have a solution to workaround this. You can try using the default column, and add a CellContentTemplate in it. I will open a support ticket on your behalf and send more details in it.

 

[Nik]

Hi Didi,

We tried using "CellContentTemplate" in the RadDataGrid as per your suggestion, however we still see a lag when scrolling. Attached is the video showing the lag using CellContentTemplate.

As mentioned in my earlier comment, we are experiencing the lag issue with the "RadListView" control too. Do you have any suggestion or workaround for it? Please let us know.

[Didi]

Hi Nik,

I have opened a support ticket on your behalf and sent more details to the ticket. Could you please check my response. We can continue the communication in the support ticket.