UserControl Dependencyproperty not updating through binding - binding

Question

I'm creating a Windows 8 app, and I'm struggling the last couple of days with a custom user control. I can't really figure out whats wrong.
The weird thing is that the dependencyproperty calls the propertychanged event when I change Source in code, but with the binding its not updating.
So here's my code:
GamePage.xaml.cs
public sealed partial class GamePage
{
GamePageViewModel viewModel;
public GamePage()
{
this.InitializeComponent();
viewModel = new GamePageViewModel();
}
}
GamePage.xaml
<common:LayoutAwarePage x:Class="WordSearcher.GamePage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:common="using:WordSearcher.Common"
xmlns:controls="using:WordSearcher.Controls"
xmlns:ignore="http://www.ignore.com"
mc:Ignorable="d ignore"
d:DesignHeight="768"
d:DesignWidth="1366"
DataContext="{Binding GamePageViewModel, Source={StaticResource Locator}}">
<StackPanel Orientation="Horizontal">
<StackPanel.Background>
<ImageBrush ImageSource="Assets/Wood.jpg" Stretch="UniformToFill"/>
</StackPanel.Background>
<controls:PuzzleControl Source="{Binding Path=PuzzleData}"/>
</StackPanel>
</common:LayoutAwarePage>
GamePageViewModel.cs
public class GamePageViewModel : ViewModelBase
{
private List<string> _puzzleData;
public List<string> PuzzleData
{
get
{
return _puzzleData;
}
set
{
this._puzzleData = value;
RaisePropertyChanged("PuzzleData");
}
}
public GamePageViewModel()
{
SetNewData();
}
private async void SetNewData()
{
await SomeManager.Prepare();
PuzzleData = SomeManager.Create(20);
}
}
PuzzleControl.xaml.cs
<UserControl
x:Class="WordSearcher.Controls.PuzzleControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:WordSearcher.Controls"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="500"
d:DesignWidth="500">
<Grid x:Name="puzzleGrid"
Width="500"
Height="500"
>
</Grid>
</UserControl>
PuzzleControl.xaml.cs
public sealed partial class PuzzleControl : UserControl
{
public static readonly DependencyProperty SourceProperty =
DependencyProperty.Register("Source", typeof(ObservableCollection<string>), typeof(PuzzleControl), new PropertyMetadata(null, PropertyChanged));
private static void PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
//
// not called from binding
//
((PuzzleControl)d).OnItemsSourcePropertyChanged(e);
}
private void OnItemsSourcePropertyChanged(DependencyPropertyChangedEventArgs e)
{
Source = (ObservableCollection<string>)e.NewValue;
SetGridData();
}
public ObservableCollection<string> Source
{
get
{
return (ObservableCollection<string>)GetValue(SourceProperty);
}
set
{
SetValue(SourceProperty, value);
}
}
public PuzzleControl()
{
this.InitializeComponent();
CreateRowsAndColumns();
}
private void CreateRowsAndColumns()
{
//create rows and columns in puzzleGrid
//works fine
}
private void SetGridData()
{
//fill puzzleGrid with data
//works fine
}
}
Does anyone knows with is wrong in my code? Because when I put Source = new ObservableCollection(); in the constructor of PuzzleData, the PropertyChanged event will raise. Is it anything with the DataContext?
Thnx in advance!

Answer 1

I don't know for sure,
but you set <controls:PuzzleControl Source="{Binding Path=PuzzleData}"/>
PuzzleData = List<string>
and
Source = ObservableCollection<string>
If the binding even works the first time (what it apperantly does) then it might be the case the source is set to List<string> in some way instead of ObservableCollection<string>. That might be the case why your dependencyproperty method (PropertyChanged) is not called because it is registered to ObservableCollection<string>.
But this is all pure speculation, haven't tested it.
After I got his code an reviewed it I found out that the PuzzleData was never really set and that that was the error... False Alarm....

Answer 2

Are you sure binding context? And How binding object? If you use your user control like in a gridview, DataContext is changed, and differend Datacontext of root page.
<controls:PuzzleControl Source="{Binding Path=DataContext.PuzzleData}"/>
if you use sub control, your user control; bind ElementName property like this:
<controls:PuzzleControl Source="{Binding Path=DataContext.PuzzleData, ElementName=pageRoot}"/>
If you not sure, tracing DataContext binding values on debug via breakpoints.