WPF enable combobox based on another combobox - wpf

Question

I know there are already a lot of examples for doing similar things, and I have read these but cannot figure out why my implementation is not working.
I am trying to disable ComboBoxB when ComboBoxA is set to value X. With this implementation, ComboBoxB is always enabled regardless of the value selected in ComboBoxA.
ComboBoxA:
<ComboBox Name="ComboBoxA">
<ComboBoxItem Name="X">X</ComboBoxItem>
<ComboBoxItem Name="Y">Y</ComboBoxItem>
</ComboBox>
ComboBoxB:
<ComboBox Name="ComboBoxB">
<ComboBoxItem Name="Something">Something</ComboBoxItem>
<ComboBox.Style>
<Style TargetType="{x:Type ComboBox}">
<Setter Property="IsEnabled" Value="True" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=SelectedItem,ElementName=ComboBoxA}" Value="X">
<Setter Property="IsEnabled" Value="False" />
</DataTrigger>
</Style.Triggers>
</Style>
</ComboBox.Style>
</ComboBox>

Answer 1

You never performed a databinding to ComboboxA.
Your referencing elementname "ComboboxA" and NOT "ComboboxB"
You have:
<DataTrigger Binding="{Binding Path=SelectedItem,ElementName=ComboBoxB}" Value="X">
This should be:
<DataTrigger Binding="{Binding Path=SelectedItem,ElementName=ComboBoxA}" Value="X">
.
<ComboBox Name="ComboBoxB">
<ComboBoxItem Name="Something">Something</ComboBoxItem>
<ComboBox.Style>
<Style TargetType="{x:Type ComboBox}">
<Setter Property="IsEnabled" Value="True" />
<Style.Triggers>
<DataTrigger Binding="{Binding Path=SelectedItem,ElementName=ComboBoxA}" Value="X">
<Setter Property="IsEnabled" Value="False" />
</DataTrigger>
</Style.Triggers>
</Style>
</ComboBox.Style>
</ComboBox>

Answer 2

You could use converters to do this.
public class SelectedItemToDisable : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value != null)
{
var val = (value as ComboBoxItem).Content;
if (val.ToString() == "X") //may be its not string, some object type
return false;
}
return true;
}
define the converter in resources part in Xaml.
<local:SelectedItemToDisable x:Key="DisableConverter"/>
<ComboBox Name="ComboBoxA">
<ComboBoxItem Name="X">X</ComboBoxItem>
<ComboBoxItem Name="Y">Y</ComboBoxItem>
</ComboBox>
<ComboBox Name="ComboBoxB" IsEnabled="{Binding Path=SelectedItem, ElementName=ComboBoxA, Converter={StaticResource DisableConverter}}">
<ComboBoxItem Name="Something">Something</ComboBoxItem>
</ComboBox>
Hope this helps.