Change listbox template on lost focus event in WPF

Question

I want to present a listbox with TextBlocks as items. When the user clicks/selects an item it changes into a TextBox for editing. As soon as the controls loses focus the item would turn back to a TextBlock.

The following XAML is almost working in that the TextBlock does turn into a TextBox when it's selected. It also turns back to a TextBlock if I select another item on the list. The problem is that if I move out of the listbox (in this case to the Add New text box) the list item stays as a TextBox.

The question ( WPF ListViewItem lost focus event - How to get at the event? ) looked promising but I can't make it work. I tried using the IsFocused property but then I wasn't able to edit the textbox because when I got into the textbox the listboxitem would go out of focus and thus turning back to a TextBlock before I had a chance to edit the text.

How can I make the TextBox turn back to TextBlock if the listbox/item loses the focus?

(Any other implementation that accomplishes the goal are also welcomed)

<Window x:Class="MyView.MainWindow1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
        Title="MainWindow1" Height="300" Width="200">
    <Window.Resources>
        <DataTemplate x:Key="ItemTemplate">
            <TextBlock Text="{Binding Name}" />
        </DataTemplate>

        <DataTemplate x:Key="SelectedTemplate">
            <TextBox Text="{Binding Name, Mode=TwoWay}" />
        </DataTemplate>

        <Style TargetType="{x:Type ListBoxItem}" x:Key="ContainerStyle">
            <Setter Property="ContentTemplate" Value="{StaticResource ItemTemplate}" />
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="ContentTemplate" Value="{StaticResource SelectedTemplate}" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

    <StackPanel >
        <ListBox ItemsSource="{Binding Departments}" HorizontalContentAlignment="Stretch"
                 ItemContainerStyle="{StaticResource ContainerStyle}" />
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="Auto" />
            </Grid.ColumnDefinitions>
            <TextBox  Text="{Binding NewDepartmentName, Mode=TwoWay}"  />
            <Button Grid.Column="1" Width="50" Content="Add" Command="{Binding Path=AddNewDepartmentCommand}" />
        </Grid>
    </StackPanel>
</Window>

Use an attached property on the ListBox to hack your way into it. Do a foreach on the items (and items changing). Latch onto each item's Focus event/property and when it changes, use VisualTreeHelper or LogicalTreeHelper to see if any children (i.e. TextBox) have focus.. — Jake Berger
I tried doing this but failed miserably. Could you please post an example of how to do it? — Manuel
I just took another shot at modifying the textbox's look (Phil's answer) and I now have something I can work with. Thanks. — Manuel

Phil Phil · Accepted Answer · 2012-02-24T23:07:15

This doesn't answer your question, but gives an alternative solution by making a textbox look like a textblock when the listboxitem isn't selected:

<Page.Resources>
    <ResourceDictionary>
        <Style x:Key="ListBoxSelectableTextBox" TargetType="{x:Type TextBox}">
            <Setter Property="IsHitTestVisible" Value="False" />
            <Style.Triggers>
                <DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBoxItem}, AncestorLevel=1}}" Value="True">
                    <Setter Property="IsHitTestVisible" Value="True" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </ResourceDictionary>
</Page.Resources>
<Grid>
    <ListBox ItemsSource="{Binding Departments}" HorizontalContentAlignment="Stretch">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBox Margin="5" Style="{StaticResource ListBoxSelectableTextBox}" Text="{Binding Name}" BorderBrush="{x:Null}"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</Grid>

Change listbox template on lost focus event in WPF

2 Answers