Question

I wish to do this using only XAML – How to add an additional RadComboBoxItem to data bound RadComboBox? – is this possible ?

I have an observable collection that is populating a combo box.

                <telerik:RadComboBox Grid.Row="0" ItemsSource="{Binding ListOfNumbers}" DisplayMemberPath="Name" EmptyText="All" SelectedItem="{Binding SelectedNumber, Mode=TwoWay}"/>

As you can see, at the moment I have the EmptyText property set to “All”. This works perfectly, in the method where the value of this combobox is used, I check it, if it is == "", if it is, then it retrieves all data. This is what happens when I first open my view, with nothing selected.

The problem is, when I select a number, I can no longer select “All”, which is quite annoying as I would like to be able to.

How can I add this choice to my comboBox and make it save a value of “” to my dependency property, SelectedNumber ?

Answer 1

Something like this should work:

<telerik:RadComboBox.ItemsSource>
    <CompositeCollection>
      <CollectionContainer
        Collection="{Binding ListOfNumbers}" />

      <telerik:RadComboBoxItem Name="Default" Content="All Builds" Value=""></telerik:RadComboBoxItem >
    </CompositeCollection>
  </telerik:RadComboBox.ItemsSource>

No ?