Silverlight 4 DataBinding: Binding to ObservableCollection<string> not working anymore
- by Kurt
Upgrading from SL3 - SL4. First problem: this throws a parser exception:
<StackPanel Name={Binding} /> (same with x:Name)
Collection is ObservableCollection<string>. Worked fine in SL3. So it seems that SL4 doen't allow binding to the Name property. Huh?
So: changed to
<StackPanel Tag={Binding} />
... since I just need to ID the control in code behind. So here's the bug ('cuz this has got to be a bug!):
In this frag, AllAvailableItems is an ObservableCollection<string>:
<ItemsControl Name="lbItems"
ItemsSource="{Binding AllAvailableItems}"
Height="Auto"
Width="Auto"
BorderBrush="Transparent"
BorderThickness="0"
VerticalAlignment="Top"
HorizontalAlignment="Left"
Margin="12,6,0,0">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<CheckBox Tag="{Binding}"
Checked="ItemChecked_Click"
Unchecked="ItemUnchecked_Click"
Style="{StaticResource CheckBoxStyle}"
Grid.Row="0">
<CheckBox.Content>
<TextBlock Text="{Binding}"
Style="{StaticResource FormLJustStyle}" />
</CheckBox.Content>
</CheckBox>
<StackPanel Tag="{Binding}"
Orientation="Vertical"
Grid.Row="1">
<configControls:ucLanguage /> <!-- simple user control -->
</StackPanel>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
In the code behind, I use a recursive function to find the Dependency object with either the Name or Tag property provided:
public static T FindVisualChildByName<T>(DependencyObject parent, string name, DependencyProperty propToUse) where T : DependencyObject
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
string controlName = child.GetValue(propToUse) as string;
if (controlName == name)
{
return child as T;
}
else
{
T result = FindVisualChildByName<T>(child, name, propToUse);
if (result != null)
return result;
}
}
return null;
}
OK, get this: in the code behind, I can get the control that is ORDERED FIRST in the XAML! In other words, if I put the CheckBox first, I can retrieve the CheckBox, but no StackPanel. And vice-versa. This all worked fine in SL3.
Any help, ideas ... ?
Thanks - Kurt
