What do you mean by combobox value. do you mean enable-diable combo box has list of items or not. If this is the case, you can use following code
public class ComboBoxEnableConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
bool hasItem = (bool)value;
if (hasItem)
return true;
return false;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
Then Add to Resource and bind to Enable property as given below
<UserControl.Resources>
<common:ComboBoxEnableConverter x:Key="EnableConverter"/>
</UserControl.Resources>
<ComboBox x:Name="cmboBox" IsEnabled="{Binding ElementName=cmboBox, Path=HasItems, Converter={StaticResource EnableConverter}}"/>
1. Define converter if you want to convert source value into target e.g items count to boolean (IsEnable on accepts boolean)
2. Bind IsEnable property to your requirement. In this example I want to check if combo box has some items in item source. if yes, Converter will return true, else false