Question

I’m generating a List of TextBoxes within an ItemsControl like so :

<ItemsControl ItemsSource="{Binding CurrentCandidate.Properties}">
 <ItemsControl.ItemTemplate>
  <DataTemplate>
    <DockPanel>
      <TextBlock DockPanel.Dock="Top" Text="{Binding DisplayName}" />
      <Border DockPanel.Dock="Top">
        <TextBox Text="{Binding Value, UpdateSourceTrigger=PropertyChanged}">
          <TextBox.InputBindings>
            <KeyBinding Command="{?}" CommandParameter={?} Key="PgUp" />
            <KeyBinding Command="{?}" CommandParameter={?} Key="Enter" />
          </TextBox.InputBindings>
     </TextBox>
       </Border>
     </DockPanel>
    </DataTemplate>
 </ItemsControl.ItemTemplate>
</ItemsControl>

Within the input-Bindings I want to access a Command that’s available at ViewModel-Level, at the same level as the ItemsSource, that is. In Order to access it from within the ItemTemplate, I used the following workaround up to now :

    <TextBlock x:Name="tbCurrentCandidate"
               Tag="{Binding Path=CurrentCandidate}"
               Visibility="Hidden"></TextBlock>
    <TextBlock x:Name="tbReset"
               Tag="{Binding Path=ResetInputCommand}"
               Visibility="Hidden"></TextBlock>
    <TextBlock x:Name="tbValidate"
               Tag="{Binding Path=ValidateCommand}"
               Visibility="Hidden"></TextBlock>

<TextBox.InputBindings>
  <KeyBinding Command="{Binding ElementName=tbReset, Path=Tag}"
   CommandParameter="{Binding ElementName=tbCurrentCandidate, Path=Tag}"
   Key="PgUp" />
  <KeyBinding Command="{Binding ElementName=tbValidate, Path=Tag}"
   CommandParameter="{Binding ElementName=tbCurrentCandidate, Path=Tag}"
   Key="Enter" />
</TextBox.InputBindings>

This is a HTML-Hidden-Field-like workaround to access the properties that are not available where I need them, but I suppose there must be a better way than that…

Anyone who can help me out : feel hugged for making that piece of misery a bit less miserable 😉

Answer 1

Use something like

{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}, Path=Name}

Replace ItemsControl by the parent control type that has a DataContext containing the desired commands.