Vertical Scrollbar issue -- when you delete and re-add items.

[Donald Hamm]

Using the latest RadGrid, I've noticed if I have items in a grid (say 4) that cause a vertical scrollbar, I can scroll the grid to the bottom then I initiate an action that will cause that grid to 'reload' new items -- say just one or two.  If I don't 'scroll' to the top before I initiate the action, once the new items are loaded, the grid does not show them (just an empty grid) or will show just one (if 2 items were loaded) yet I can look @ the grid in debug mode and see it has the 1 or 2 new records.

If I load the previous items, scroll the grid back to the top (using the thumb or up/down arrows) and then initiate the action that loads the 1 or 2, the grid will load the items correctly and then show them.  I do use 'UpdateLayout()' after I've release the items (null), then added the items back:

 

this.RadGridQNoteDefects.ItemsSource = null;

 

 

 

 

this.RadGridQNoteDefects.ItemsSource = _ncds;

 

 

 

 

// in order for grid events to occur during loading, you need to

 

 

 

 

// call this first. This will cause the 'DataLoaded' event to occur...

 

 

 

 

this.RadGridQNoteDefects.UpdateLayout();

 

 

 

Is there anything I can do to force the grid to 'reset' the scroll position before or after loading the items?

(grid initial options below)

 

 

<telerikGridView:RadGridView x:Name="RadGridQNoteDefects" IsReadOnly="True" ShowGroupPanel="False" RowIndicatorVisibility="Collapsed" AutoGenerateColumns="False" ColumnsWidthMode="Fill" CanUserFreezeColumns="False" DataLoadMode="Synchronous" >

 

 

 

Basically, it looks as if the grid is saving the 'last' scroll position in between data loads...

Thanks!

-Don

[Nedyalko Nikolov]

Hello Donald Hamm,

This issue is already fixed and will be available with latest internal build next Friday. For now as a workaround you can use RadGridView.ItemsControl.VirtualizingPanel.SetVerticalOffset(0d) when you change data source of the RadGridView.

Sorry for the inconvenience caused.

Greetings,
Nedyalko Nikolov
the Telerik team

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[Donald Hamm]

Fantastic!  Thanks for the reply!  I'll use that until the next build....  Great job folks!...

[Wolfgang Colsman]

I have a similar problem with 00395RadControls_for_Silverlight4_2009_3_1322_Trial.zip.

1. I add e.g. 10 items and scroll down.
2. I call items.clear()
3. I add e.g. 20 items -> the thumb of the scrollbar is somwhere in the middle.

Ii do not find the ItemsControl property in GridView.

Regards

Wolfgang

[Vlad]

Hello Wolfgang,

You can scroll the grid to the first item using ScrollIntoView() method:

RadGridView1.ScrollIntoView(RadGridView1.Items[0]);

All the best,
Vlad
the Telerik team

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