VirtualQueryableCollectionView with RadGridView and SelectionMode.Extended

4 posts, 0 answers
  1. Michael
    Michael avatar
    3 posts
    Member since:
    Nov 2014

    Posted 13 Apr Link to this post

    I have a RadGridView (SelectionMode.Extended) with ItemsSource of type VirtualQueryableCollectionView. Source is a database wich is connected via EntityFramework.
    When I select the first row in the GridView and go down to the bottom and select the last row (or any other), all items in between are fetched from the databse, although I didn't pressed SHIFT. This needs very much time I have many data.
    Is there any reason, why the table thinks it has to load all rows between the first an the second selection? Is there any way, to change this behaviour?
    I think, this should only happen, if I SHIFT+Click on a row.

  2. Maya
    Admin
    Maya avatar
    4062 posts

    Posted 15 Apr Link to this post

    Hi Michael,

    Generally, when scrolling VQCV tries to load all items that should be displayed in the corresponding range of offsets. Could you clarify what you would expect in such scenarios? Do you get different behavior when selecting first and last items and when not? 

    Regards,
    Maya
    Telerik
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  4. Michael
    Michael avatar
    3 posts
    Member since:
    Nov 2014

    Posted 15 Apr in reply to Maya Link to this post

    Hi Maya,

    it is correct that when I am scrolling, all items should be loaded, but my case is another.

     

    example:

    The LoadSize of VirtualQueryableCollectionView is 100. The database contains 5000 items.

    When I select any item in the first 100 loaded items, all is fine. When I jump to any area in GridView, for example to the last item (CTRL+End Key), the GridView loads the displayed range of items (items from index 4900-5000), that's correct. If I try to select for example the last item (without pressing the SHIFT-Key), all items from index 0 up to the selected index (the last one, 5000) are loaded, although I don't need them, because this should behave like the SelectionMode.Single. All this items should only be loaded, if I really press the SHIFT-Key, because only in this case I need all the items. This problem is the same, if I jump to any area in the GridView by dragging the Scrollbar with the mouse, for example to the item at index 2500.

    Regards,

    Michael

  5. Maya
    Admin
    Maya avatar
    4062 posts

    Posted 19 Apr Link to this post

    Hello Michael,

    Indeed, you are absolutely right and I managed to reproduce the issue quite easily thanks to your detailed explanation. I logged it in our feedback portal where you can track its progress and we can schedule it for a future fix. I also updated your Telerik points for reporting it. 

    Regards,
    Maya
    Telerik
    Do you need help with upgrading your AJAX, WPF or WinForms project? Check the Telerik API Analyzer and share your thoughts.
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