Question

I have ElementFlowContainer user control that contains ElementFlow from FluidKit.Showcase project.

<UserControl x:Class="Controls.ElementFlowContainer">
<Grid>
<-- Other controls (cut) -->
<Controls:ElementFlow x:Name="_elementFlow" ItemsSource="{Binding}" ItemTemplate="{DynamicResource TestDataTemplate}" SelectedIndex="3">
<-- Layout, Background, Camera settings (cut) -->
</Controls:ElementFlow>
</Grid>
</UserControl>

I have ObservableCollection that serves as DataContext of ElementFlow :

<Controls:ElementFlowContainer DataContext="{Binding MediaRecords}"/>

MediaRecord has image property (byte[] Content) which i want to display. Here’s template :

<DataTemplate x:Key="TestDataTemplate" 
DataType="{x:Type DAL:MediaRecord}">
<Border x:Name="ElementVisual" Background="White" BorderThickness="2" BorderBrush="#ff9e8028">
<Image Source="{Binding Content}" Stretch="Fill" />
</Border>
</DataTemplate>

All the stuff above is in ViewModel which is created by IoC container (MediaRecords property is null during initialization). When collection is filled with items I get

"InvalidOperationException '[Unknown]' property does not point to a DependencyObject in 
path "(0)[0].(1)[1].(2).(3)[0].(4)."

This error happens in RaisePropertyChanged in property setter :

public const string MediaRecordsPropertyName = "MediaRecords";
public ObservableCollection<MediaRecord> MediaRecords
{
 get { return _mediaRecords; }
 set 
 { if (_mediaRecords == value) { return; } _mediaRecords = value;
   RaisePropertyChanged(MediaRecordsPropertyName); // error here         
 }
}

Any idea how to fix this?
edit
Same collection is bound to another control, so i guess this issue is concurrency related. Fixed it quick-and-dirty by maintaining second copy of collection and binding to it, but maybe there is a better way?

Answer 1

Solution with separate collection worked, issue now may be closed.