WPF: "Items collection must be empty before using ItemsSource."
- by Zack Peterson
I'm trying to get images to display in a WPF ListView styled like a WrapPanel as described in this old ATC Avalon Team article: How to Create a Custom View.
When I try to populate the ListView with a LINQ-to-Entities queried collection of ADO.NET Entity Framework objects I get the following exception:
Exception
Items collection must be empty before
using ItemsSource.
My code…
Visual Basic
Private Sub Window1_Loaded(...) Handles MyBase.Loaded
ListViewImages.ItemsSource = From g In db.Graphic _
Order By g.DateAdded Ascending _
Select g
End Sub
XAML
<ListView Name="ListViewImages"
SelectionMode="Single"
ItemsSource="{Binding}">
<local:ImageView />
</ListView>
I put a breakpoint on that line. ListViewImages.ItemsSource is Nothing just before the LINQ assignment.