Enable TextBox when ListViewItem is selected in WPF (databinding) - wpf

Question

How can i enable/disable a TextBox with DataBinding in WPF when a ListViewItem is (not) selected?
I have created a converter class:
public class BoolConvert : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return value == null;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new Exception("The method or operation is not implemented.");
}
}
and added the property to the TextBox:
IsEnabled="{Binding SelectedItem, ElementName=listViewCards, Converter={StaticResource BoolConvert}}"
but i have a XamlParseException becouse he can´t find the class :-(

Answer 1

You could alternately use a style trigger on the TextBox, eliminating the need for a ValueConverter:
<TextBox>
<TextBox.Style>
<Style TargetType="{x:Type TextBox}">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=lvItems, Path=SelectedItem}" Value="{x:Null}">
<Setter Property="IsEnabled" Value="True"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
<ListView Name="lvItems" .../>

Answer 2

You can bind the IsEnabled property on the TextBox to the SelectedItem property on the ListView. Then you'll need a converter (an implementation of IValueConverter) to convert selected values into boolean values.
<TextBox IsEnabled="{Binding SelectedItem, ElementName=listView, Converter={StaticResource MyConverter}}"/>
<ListView x:Name="listView" .../>
Then, in your converter:
public object Convert(object value, ...)
{
return value == null;
}

Answer 3

ListViewItem in ListView :
Enable if Selected.
Try the following:
<ListViewItem Margin="5" Background="AliceBlue">
<TextBox Margin="5" Text="Lösung SECHS"
IsEnabled="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListViewItem}}, Path=IsSelected}"/>
</ListViewItem>