Virtualization Issue

2 posts, 0 answers
  1. Sergey
    Sergey avatar
    26 posts
    Member since:
    Jun 2012

    Posted 16 Jul 2014 Link to this post

    I took example project from this thread

    I'd like to be able to select multiple clubs and perform an operation on them. I also would like virtualization to be enabled for better performance.

    I've added IsSelected property to Club object to track which clubs are selected and for this example I do simple counting of selected clubs on button click.

    When I select grid rows inside viewport IsSelected property is correctly changed on them and I receive correct count on button click.

    When I select all rows with Ctrl+A shortcut or using Shift+Click, IsSelected property is changed only on visible rows inside viewport and count returns not 400, but 10-30, depending on the size of browser window.

    Is it possible to track reliably selected rows outside viewport without disabling virtualization?

    Attached is modified project with observed issue (rename png to zip).
  2. Dimitrina
    Dimitrina avatar
    3769 posts

    Posted 17 Jul 2014 Link to this post


    The Extended selection with VirtualQueryableCollectionView is only recommended when the selected items are in the View area. It is not possible to actually select items outside it as the items to be eventually selected/displayed are still not presented. This is the case until the user scrolls to a particular position so that the items to be displayed into view are actually loaded. 

    I am afraid this collection was designed to serve mostly ReadOnly scenarios and its capabilities are limited. 

    Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time. Watch the videos and start improving your app based on facts, not hunches.
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