Silverlight binding visibility to parent class property - silverlight

Question

I have problem with binding visibility in listbox-item template with property in parent object. Here is a little snippet from custom xaml style template:
<!-- DATA BINDING ITEM TEMPLATE -->
<StackPanel Orientation="Vertical">
<TextBlock Height="19"
....
Text="{Binding InfoTop}"/>
<Rectangle Height="1"
....
Visibility="{Binding _linesVisibility[0], RelativeSource={RelativeSource AncestorType=my:PatientsList}}"/>
<TextBlock Height="19"
....
Text="{Binding InfoMiddle}"
Visibility="{Binding _linesVisibility[0], ElementName=patientsControl}"/>
<Rectangle Height="1"
....
Visibility="{Binding _linesVisibility[1]}"/>
<TextBlock Height="19"
....
Text="{Binding InfoBottom}"
Visibility="{Binding _linesVisibility[1]}"/>
</StackPanel>
I managed to bind Text value by assigning ItemsSource in code file but i can't bind Visibility. As you can see i tried some different ideas but none of them work.
I have public variable public Visibility[] _linesVisibility = new Visibility[2]; in my custom control. This control contains listbox with custom style as above. How to bind properly my _linesVisibility to listbox-item style ?

Answer 1

You can't bind directly to an array:
Visibility="{Binding _linesVisibility[1]}"
This will not work.
You need to bind to a property and your class needs to implement INotifyPropertyChanged:
private Visibility backingVariable;
public Visbilility PublicProperty
{
get { return backingVariable; }
set
{
backingVariable = value;
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs("PublicVariable"));
}
}
}
It doesn't have to be a property of type Visibility. It can be any type as long as you bind through a converter that returns Visibility:
public class BoolToVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
bool visibility = (bool)value;
return visibility ? Visibility.Visible : Visibility.Collapsed;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
Visibility visibility = (Visibility)value;
return (visibility == Visibility.Visible);
}
}
Usage:
Visibility="{Binding SomeBoolean, Converter={StaticResource boolToVisibilityConverter}}"
where the converter is declared in XAML like this:
<UserControl.Resources>
<globalConverters:BoolToVisibilityConverter x:Key="boolToVisibilityConverter" />
</UserControl.Resources>