Question

I”m trying to get my head wrapped around the WPF model.

I have a list box of items. Inside the list box items are string identifiers. This works fine. What I want is to have it so that the identifier from the currently selected item is accessible in my code-behind for the enclosing control.

I have this:

<ListBox.ItemTemplate>
 <DataTemplate>
   <StackPanel Width="320">
    <Label Content="{Binding Path=ShortName}" Style="{StaticResource ListHeader}"/>
      <TextBlock TextWrapping="Wrap" Text="{Binding Path=Description}" Style="{StaticResource ListText}" />
   </StackPanel>
 </DataTemplate>
 </ListBox.ItemTemplate>

And I think I should add something like:

<DataTemplate.Triggers>
    <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ListBoxItem}},Path=IsSelected}" Value="True">
    <Setter Property="" TargetName="">
     <Setter.Value>

     </Setter.Value>
   </Setter>
 </DataTrigger>

But I’m lost as to how to set-up the setter to set a property that’s part of the enclosing control (ie, the outside world). I think I have this backwards somehow?

Answer 1

If you are trying to access a property on a selected list box item from outside of the listbox then you can do the following in your code behind:

CustomItem item = (CustomItem)listBox1.SelectedItem;
MessageBox.Show(item.ShortName);

And your xaml is as follows:

<ListBox Height="100" Name="listBox1">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <StackPanel Name="stackPanel1">
                    <Label Content="{Binding Path=Shortname}"/>
                    <TextBlock Text="{Binding Path=Description}"/>
                </StackPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

You just cast the selecteditem from the listbox to your object type, then access the property on the object.

Hope this is what you were after.