Question

I am working on a wpf application using PRISM. This is my first ever WPF application and I have found myself in a situation where I can’t go forward.

My scenario is this, I have a List of groups which I am binding with a ListBox, you can call it parent ListBox, each group object has a list of users associated to it and I am binding that list with another ListBox which is nested in the parent ListBox. Both bindings are working fine as you can see here:

I am facing two problems.

1. I can select both groups and individual users withing group separately but they are not synch, means If i select a user then the group which contains this user is not getting selected. I tried IsSynchronizedWithCurrentItem=”True” but that doesn’t seems to be working.

I would greatly appreciate if someone can point me out in a right direction how to achieve this or if there is any other way beside using ListBox within a ListBox.

2. I have a context menu associated with parent ListBox and I am able to successfully bind the commands with menus, but I am having troubles binding commands with nested ListBox Context Menu, here is my code

<ListBox x:Name="lstOfGroups" 
             ItemsSource="{Binding CurrentContest.Groups}"
             SelectedItem="{Binding SelectedGroup}"
             ItemTemplate="{StaticResource GroupTemplate}"
             Style="{StaticResource ListBoxStyle1}"
             ItemContainerStyle="{StaticResource ListBoxItemStyle1}"
             Background="Transparent" SelectionMode="Single"
             IsSynchronizedWithCurrentItem="True"
             Height="400">
                <ListBox.ItemsPanel>
                    <ItemsPanelTemplate>
                        <WrapPanel Orientation="Horizontal" Margin="5" Width="1200"/>
                    </ItemsPanelTemplate>
                </ListBox.ItemsPanel>

                <ListBox.ContextMenu>
                    <ContextMenu>
                        <MenuItem Header="Add Contestant" Command="{Binding AddGroupCommand}"/>
                        <MenuItem Header="Edit Contestant" Command="{Binding EditGroupCommand}"/>
                        <MenuItem Header="Delete Contestant" Command="{Binding DeleteGroupCommand}"/>
                    </ContextMenu>
                </ListBox.ContextMenu>
            </ListBox>

<DataTemplate x:Key="GroupTemplate" >
        <Border x:Name="spPubItemBorder" Margin="3" BorderBrush="Black" BorderThickness="1" CornerRadius="10" Background="Honeydew">
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>

                <StackPanel Orientation="Horizontal">
                    <TextBlock Name="tbGroupName" Grid.Column="0" Style="{StaticResource ItemTextBox}">
                    <TextBlock.Text>
                        <MultiBinding StringFormat="{}Group Name: {0}">
                            <Binding Path="Name" />
                        </MultiBinding>
                    </TextBlock.Text>
                    </TextBlock>
                    <TextBlock Name="tbGroupAmount" Grid.Column="1" Style="{StaticResource ItemTextBox}">
                    <TextBlock.Text>
                        <MultiBinding StringFormat="{}Group Amount: {0}">
                            <Binding Path="Amount" />
                        </MultiBinding>
                    </TextBlock.Text>
                    </TextBlock>
                </StackPanel>
                <!--<ItemsControl ItemsSource="{Binding ContestantList}"
                              AlternationCount="2" ItemTemplate="{StaticResource ContestantTemplate}">

                </ItemsControl>-->
                <ListBox x:Name="lstOfContestant" Grid.Row="1"
                     ItemsSource="{Binding ContestantList}"
                     SelectedItem="{Binding SelectedContestant, ElementName=lstOfGroups}"
                     ItemTemplate="{StaticResource ContestantTemplate}"
                     Style="{StaticResource ListBoxStyleForContestant}"
                     ItemContainerStyle="{StaticResource ListBoxItemStyleForContestant}"
                     Background="Transparent" SelectionMode="Single"
                     Height="Auto">
                    <ListBox.ItemsPanel>
                        <ItemsPanelTemplate>
                            <WrapPanel Orientation="Horizontal" Margin="5" Width="375"/>
                        </ItemsPanelTemplate>
                    </ListBox.ItemsPanel>

                    <ListBox.ContextMenu>
                        <ContextMenu>
                            <MenuItem Header="Add Contestant" Command="{Binding Path=DataContext.AddContestantCommand,ElementName=contestantManager}"/>
                            <MenuItem Header="Edit Contestant" Command="{Binding Path=DataContext.EditContestantCommand,ElementName=contestantManager}"/>
                            <MenuItem Header="Delete Contestant" Command="{Binding Path=DataContext.DeleteContestantCommand,ElementName=contestantManager}"/>
                        </ContextMenu>
                    </ListBox.ContextMenu>
                </ListBox>

            </Grid>
        </Border>
    </DataTemplate>

I was wondering if someone can point me in a right direction here as well.

Thanks in advance.

Answer 1

For #1, set the IsSelected property of the group ListBox to true if IsKeyboardFocusWithin

<Style x:Key="GroupListBoxItemStyle" TargetType="ListBoxItem">
  <Style.Triggers>
    <Trigger Property="IsKeyboardFocusWithin" Value="True">
      <Setter Property="IsSelected" Value="True" />
    </Trigger>
  </Style.Triggers>
</Style>

This will set the group’s ListBoxItem as Selected when the keyboard focus is anywhere within the ListBoxItem

As for #2, it sounds like you’re getting the wrong item, probably because you’re using ElementName in your binding, however the name is set on multiple items. Try using a RelativeSource binding to find the ContextMenu itself, then bind to the PlacementTarget.DataContext

<MenuItem Header="Add Contestant"
          Command="{Binding PlacementTarget.DataContext.AddContestantCommand, 
              RelativeSource={RelativeSource FindAncestor, 
              AncestorType={x:Type ContextMenu}}}" />