Cant refresh longlistselector in WP8 Databinding

Question

I'm having some trouble with databinding to a LongListSelector. When I initally run this method, it works. The data is binded and everything is good.

The problem is when I press the refresh button, my app fetches a new JSON feed, parses it and tries to bind it. My app seems to download the JSON and stuff, but doesn't refresh the UI. Where have I gone wrong?

I've tried BoardLongList.ItemsSource = null; and BoardLongList.ItemsSource.Clear(); to no avail.

Any ideas? The JObject is from newtonsoft.json and the RootObject is from ViewModels.RootObject.

Thanks in advance!

private void Bind(JObject rootObject)
{
    string rootObjectString = rootObject.ToString();                   
    RootObject obj = JsonConvert.DeserializeObject<RootObject>(rootObjectString);

    // Bind to LongListSelector
    BoardLongList.ItemsSource = obj.Movements;
}

My XAML:

<phone:LongListSelector Grid.Row="1" x:Name="BoardLongList" Margin="0,0,-12,1" ItemsSource="{Binding Movement}">
    <phone:LongListSelector.ItemTemplate >
        <DataTemplate>
            <StackPanel Orientation="Horizontal" Margin="2" Height="50">
                <Grid>
                    <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="80" />
                         <ColumnDefinition Width="200" />
                         <ColumnDefinition Width="100" />
                         <ColumnDefinition Width="120" />
                     </Grid.ColumnDefinitions>
                     <TextBlock Grid.Column="0"  Text="{Binding A1}" />
                     <TextBlock Grid.Column="1"  Text="{Binding A2}" />
                     <TextBlock Grid.Column="2"  Text="{Binding A3}" />
                     <TextBlock Grid.Column="3"  Text="{Binding A4}" />
                 </Grid>
             </StackPanel>
         </DataTemplate>
     </phone:LongListSelector.ItemTemplate>
</phone:LongListSelector>

Answer 1

Is your ItemsSource an ObservableCollection?. ObservableCollection is collection with notification that when something is changed in the collection, it notifies the UI.

Make obj.Movements an ObservableCollection

Answer 2

Did you try the pull to refresh feature?

Check this out!

You can accomplish this with the ItemRealized event and using a ListHeader (or ListFooter to pull from bottom). Within the ItemRealized event you check if the item is your header object. If it is then load more items.

Hope it helps.

Answer 3

I finally figured it out. It was because of C# web caching my request. Not because of my databinding!