I have a problem where im trying to use a Telerik Jump List with DataVirtualizationMode.Automatic, but i can't get it to work. The reason why i want to use this, is because i want my app to only download the data(games) which is in the current view of the Jump List control and not the whole data everytime. For example if i have searched for "Batman", and its returning 50 games, i don't want it to download and load all the games, only those i can see in the Jump List control.
Here is a sample of using DataVirtualizationMode.Automatic from Telerik, but i couldn't get it to work with my app: http://www.telerik.com/help/windows-phone/raddataboundlistbox-features-datavirtualization-automatic.html
Below is my Jump List control which i want to use with data virtualization.
MainPage.xaml:
<phone:PivotItem Header="Browse">
<Grid>
<telerikPrimitives:RadTextBox Name="txtSearch" HorizontalAlignment="Left" VerticalAlignment="Top" Height="80" Width="390"/>
<telerikPrimitives:RadImageButton Name="imgBtnSeachGame" VerticalAlignment="Top" HorizontalAlignment="Right" ButtonShape="Ellipse" BorderThickness="2" Margin="0,8,0,0" Click="imgBtnSeachGame_Click"></telerikPrimitives:RadImageButton>
<Controls:RadJumpList Name="jlGameList" ItemsSource="{Binding}" Tap="jlGameList_Tap" Margin="0,90,0,0" DataVirtualizationMode="Automatic">
<Controls:RadJumpList.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="20"></RowDefinition>
</Grid.RowDefinitions>
<Border Grid.Row="0" Background="{StaticResource PhoneAccentBrush}"
Padding="{StaticResource PhoneTouchTargetOverhang}"
Margin="0,0,0,0">
<TextBlock Name="tblGameTitle" Style="{StaticResource PhoneTextGroupHeaderStyle}" ManipulationStarted="tblGameTitle_ManipulationStarted" ManipulationCompleted="tblGameTitle_ManipulationCompleted">
<Run Text="{Binding GameTitle}"></Run>
</TextBlock>
</Border>
<Grid Background="#242424" Grid.Row="1">
<Image Name="imgGameList" Margin="0,0,0,0" Stretch="Fill" HorizontalAlignment="Left" VerticalAlignment="Top" Height="96" Width="96">
<Image.Source>
<BitmapImage UriSource="{Binding BoxArtFrontThumb}"
CreateOptions="BackgroundCreation" DecodePixelHeight="96" DecodePixelWidth="96" />
</Image.Source>
</Image>
<TextBlock Margin="110,0,0,0" Text="Platform" FontWeight="Bold" TextWrapping="Wrap" Foreground="YellowGreen" FontSize="{StaticResource PhoneFontSizeNormal}"/>
<TextBlock Name="txtPlatform" Margin="110,20,0,0" Text="{Binding Platform}"></TextBlock>
<TextBlock Text="Release Date" FontWeight="Bold" Margin="110,46,0,0" Foreground="YellowGreen" FontSize="{StaticResource PhoneFontSizeNormal}"/>
<TextBlock Name="txtReleaseDate" Margin="110,66,0,0" Text="{Binding ReleaseDate}"></TextBlock>
<!--</StackPanel>-->
</Grid>
<Grid Grid.Row="2"></Grid>
</Grid>
</DataTemplate>
</Controls:RadJumpList.ItemTemplate>
</Controls:RadJumpList>
</Grid>
</phone:PivotItem>
Below is where i bind my DataContext to my GetGamesListItems ObservableCollection in my GameData class. The imgBtnSearchGame_Click event method is being called when a user have typed for example "Batman" in my textbox txtSearch and tapped the button, it will then send the text to my GetGamesListData method.
MainPage.cs:
GameData gd = new GameData();
public MainPage()
{
InitializeComponent();
jlGameList.DataContext = gd.GetGamesListItems;
}
private void imgBtnSeachGame_Click(object sender, RoutedEventArgs e)
{
if (!string.IsNullOrEmpty(txtSearch.Text))
{
gd.GetGamesListData(txtSearch.Text, "", "");
}
}
Below is where i download the data in XML for the game name searched for. For example if it is "Batman" it will find and return all games with "Batman". The "BoxArtFrontThumb" Property is where im storing all the images for each game and is using async, because sometimes there can be quite alot of images it has to download and show.
GameData.cs
public void GetGamesListData(string name, string platform, string genre)
{
var webClient = new WebClient();
webClient.DownloadStringCompleted += GetGamesListRequestCompleted;
webClient.DownloadStringAsync(new Uri("http://thegamesdb.net/api/GetGamesList.php?name=" + name));
}
private async void GetGamesListRequestCompleted(object sender, DownloadStringCompletedEventArgs e)
{
if (e.Error == null)
{
GetGamesListItems.Clear();
var feedXml = XDocument.Parse(e.Result);
var gameDataTasks = feedXml.Root.Descendants("Game").Select(
async x => new GetGamesList
{
ID = (int)x.Element("id"),
GameTitle = (string)x.Element("GameTitle"),
ReleaseDate = (string)x.Element("ReleaseDate") ?? "N/A",
Platform = (string)x.Element("Platform") ?? "N/A",
BoxArtFrontThumb = new Uri(await GetBoxArtFrontThumbAsync((int)x.Element("id")), UriKind.RelativeOrAbsolute),
}).ToList();
var gameData = await Task.WhenAll(gameDataTasks);
foreach (var item in gameData)
{
GetGamesListItems.Add(item);
}
}
}
Below is where its finding and storing the images for the games.
public async Task<string> GetBoxArtFrontThumbAsync(int id)
{
var client = new HttpClient();
var result = await client.GetStringAsync("http://thegamesdb.net/api/GetArt.php?id=" + id);
var feedXml = XDocument.Parse(result);
var gameData = feedXml.Root.Descendants("Images").Select(x => new GetArt
{
BoxArtFrontThumb = new Uri(GetBoxArtFrontThumb(x), UriKind.RelativeOrAbsolute),
}).ToList();
return gameData.Single().BoxArtFrontThumb.ToString();
}
private static string GetBoxArtFrontThumb(XElement gameNode)
{
string data = "http://thegamesdb.net/banners/" + (string)gameNode.Descendants("boxart")
.FirstOrDefault(b => (string)b.Attribute("side") == "front");
if (data == "http://thegamesdb.net/banners/")
{
data = "/NoImage.jpg";
}
return data;
}
I really hope i explained this well enough and hope that there is someone that can help me solve this problem. Thanks.
Although you are using JumpList, the mechanism for Virtualizing the data is the same as the DataBoundListBox. (You can find more information here in the DataBoundListBox docs. There is a good tutorial using an OData service.)
In order for the Automatic mode to work properly, you need to be using Telerik's VirtualizingDataCollection object and initialize it with the proper arguments (count and page size).
I don't see this in the code you have provided above, can you please open a support ticket so that I can investigate further? See my comment above for the link. Let me know the ticket number and I'll provide further assistance.