I am trying to make a customized UserControl which includes a ListView. I would like to bind the SelectedItem Property to my View Model. I therefore created a DP in my User Control and bound the SelectedItem Property of the ListView to the new Dependency Property.
public static readonly DependencyProperty SelectedItemProperty = DependencyProperty.Register(
"SelectedItem",
typeof(object),
typeof(DragAndDropListView),
new PropertyMetadata(SelectedItemPropertyChangedCallback));
private static void SelectedItemPropertyChangedCallback(DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
if (d is DragAndDropListView dragAndDropListView)
{
}
}
public object SelectedItem
{
get => GetValue(SelectedItemProperty);
set => SetValue(SelectedItemProperty, value);
}
In the xaml code I then made a binding
<ListView Name="ListView"
PreviewMouseLeftButtonDown="ListViewPreviewMouseLeftButtonDown"
AllowDrop="True"
MouseMove="ListViewMouseMove"
DragEnter="ListViewDragEnter"
Drop="ListViewDrop"
SelectedItem="{Binding Path= SelectedItem}"/>
And to make sure it works I assigned the UserControl as DataContext to the ListView
public DragAndDropListView()
{
InitializeComponent();
ListView.ItemsSource = Items;
ListView.DataContext = this;
}
And then I added a binding where I use the UserControl.
<userControls:DragAndDropListView
Items="{Binding SelectedCustomers}"
SelectedItem="{Binding SelectedCustomer}"
DisplayMemberPath="Name"
Grid.Column="0"
Grid.Row="0"/>
As you may see I thought, that I don't need a SelectedItemPropertyChangedCallback. First I didn't even implement it. I added it later to add a break point to see if it even works. When I select an item in the listView it calls the callback. But the setter of the SelectedCustomer in my ViewModel is never called.
I would expect this to work. Please help me to understand my mistake.
