Question

I’m trying to set a default selected value when ItemsSource property changes on my ComboBox

My xaml :

<ComboBox ItemsSource="{Binding SelectedItemsSource, Mode=OneWay}" x:Name="c1">
   <i:Interaction.Triggers>
         <ei:PropertyChangedTrigger Binding="{Binding ItemsSource,RelativeSource={RelativeSource Self}}">
              <ei:ChangePropertyAction PropertyName="SelectedIndex" Value="{StaticResource zero}" TargetName="c1"/>
         </ei:PropertyChangedTrigger>                        
   </i:Interaction.Triggers>             
</ComboBox>

The SelectedItemsSource in my VM changes dynamically and I want to have the first item selected each time this happens .

Any idea why this doesn’t work?

Answer 1

Try setting property IsSynchronizedWithCurrentItem to true for your combobox and remove the trigger completely –

<ComboBox ItemsSource="{Binding SelectedItemsSource, Mode=OneWay}"
          IsSynchronizedWithCurrentItem="True">             
</ComboBox>