title: 'MultiBinding' cannot be used within a 'SetterBaseCollection'
body: <p>I just started to programm in C# and got the following error message "A 'MultiBinding' cannot be used within a 'SetterBaseCollection' collection. A 'MultiBinding' can only be set on a DependencyProperty of a DependencyObject". My dea was to disable some of the combobox depedant of the input values given to the converter.  use the same converter later in the xaml file and have no error..</p>
  
  <pre><code>    &lt;DataTemplate x:Key="ComboBoxDirectionCellDataTemplate"&gt;
           &lt;Canvas&gt;
              &lt;ComboBox Name="DirectionBi" ItemsSource="{Binding Source={StaticResource DirectionBiList}}" SelectedItem="{Binding Direction, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Background="#FFCDCDCD" /&gt;
              &lt;ComboBox Name="DirectionOut" ItemsSource="{Binding Source={StaticResource DirectionOutList}}" SelectedItem="{Binding PinFunctionOptions[SelectedPinFunctionIdx].SupportedDirections, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Background="#FFCDCDCD" /&gt;
              &lt;ComboBox Name="DirectionIn" ItemsSource="{Binding Source={StaticResource DirectionOutList}}" SelectedItem="{Binding PinFunctionOptions[SelectedPinFunctionIdx].SupportedDirections, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Background="#FFCDCDCD" /&gt;
          &lt;/Canvas&gt;
          &lt;DataTemplate.Triggers&gt;
              &lt;DataTrigger Value="In"&gt;
                  &lt;MultiBinding Converter="{StaticResource FunctionToGroupConverter}"&gt;
                      &lt;Binding Path="PinFunctionOptions"/&gt;
                      &lt;Binding Path="SelectedPinFunctionIdx"/&gt;
                  &lt;/MultiBinding&gt;
                  &lt;Setter TargetName="DirectionBi" Property="Visibility" Value="Hidden"/&gt;
  </code></pre>
  
  <p>Thanks for help!!!!         </p>