Showing Camera Roll pictures

[JDBPocketware]

Hello

I am listing pictures from the phone's "camera roll", however it does not load async. When having more than 20 photos it lags about 3 seconds to then display all the pictures at once, items are not drawn progressively.

Load list:

var library = new MediaLibrary();
var photos = (from p in library.RootPictureAlbum.Albums[1].Pictures
                                select new ImageWrapper(p)).ToArray();
list.ItemsSource = photos;

ImageWrapper:

public class ImageWrapper{
    public Picture Picture { get; set; }
    public ImageWrapper(Picture picture){
        Picture = picture;
    }
    public ImageSource Image{
        get{
            var image = new WriteableBitmap(100,100);
            image.SetSource(Picture.GetThumbnail());
            return image;
        }
    }
}

Xaml:

<telerikPrimitives:RadDataBoundListBox x:Name="list" ItemTemplate="{StaticResource itemTpl}" DataVirtualizationMode="Automatic">
<telerikPrimitives:RadDataBoundListBox.VirtualizationStrategyDefinition>
 <telerikPrimitives:WrapVirtualizationStrategyDefinition Orientation="Horizontal"/>
</telerikPrimitives:RadDataBoundListBox.VirtualizationStrategyDefinition>
</telerikPrimitives:RadDataBoundListBox>

I am using the latest 2012.1.301.2040 dev hotfix. I guess issue is the same as on this case.

[Todor]

Hi Jandieg,

Thank you for your question.

If you want the items to be drawn progressively, you can set the IsAsyncBalanceEnabled property to true, which will cause each visual container to be realized asynchronously upon initial binding. You can read about Asynchronous Balance in our online documentation here.

I also noticed that you have set DataVirtualizationMode to Automatic, but it has no effect unless the itemsSource is of type VirtualizingDataCollection. You can read more about the data virtualization in RadDataBoundListBox here.

I hope this information helps. Let me know if you need additional assistance.

Kind regards,
Todor
the Telerik team