<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:WpfApplication1" Title="Debug Data Bindings Using an IValueConverter" Width="200" Height="200"> <Window.Resources> <local:DummyConverter x:Key="DummyConverter" /> </Window.Resources> <Grid> <Grid.RowDefinitions> <RowDefinition Height="0.5*" /> <RowDefinition Height="0.5*"/> </Grid.RowDefinitions> <CheckBox x:Name="chkShouldItBeOpen" IsChecked="False" Content="Open" Margin="10"/> <Expander IsExpanded="{Binding ElementName=chkShouldItBeOpen, Path=IsChecked,Converter={StaticResource DummyConverter}}" Grid.Row="1" Background="Black" Foreground="White" Margin="10" VerticalAlignment="Center" HorizontalAlignment="Center" Header="Expander!"> <TextBlock Text="Open!" Foreground="White"/> </Expander> </Grid> </Window> //File:Window.xaml.cs using System.Windows; using System; using System.Globalization; using System.Windows.Data; namespace WpfApplication1 { public partial class Window1 : Window { public Window1() { InitializeComponent(); } } public class DummyConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { return value; } public object ConvertBack(object value,Type targetType,object parameter,CultureInfo culture) { return value; } } }