WPF MVVM TreeView IsSelected binding not working

Question

I have a problem that I cannot see why it's not working. I have a 3 level Treeview with a converter which allow me to invert the two first level. On this TreeView I'm trying to bing the IsSelected Property but for a reason I don't understand it is never call in the ViewModel.

Here is the xaml.

<TreeView  Margin="0,0,0,0" Padding="0,7,0,7" BorderBrush="{x:Null}"  Background="#FFF8FAFB" Name="BusinessCaseTreeView">
    <TreeView.ItemContainerStyle>
        <Style TargetType="{x:Type TreeViewItem}">
            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
        </Style>
    </TreeView.ItemContainerStyle>
    <TreeView.ItemsSource>
        <MultiBinding Converter="{converter:BusinessCasesConverter}">
            <Binding Path="BusinessCases"></Binding>
            <Binding Path="GroupByCreditor"></Binding>
        </MultiBinding>
    </TreeView.ItemsSource>
    <TreeView.Resources>
        <HierarchicalDataTemplate DataType="{x:Type converter:BusinessCaseTreeViewableFirst}" ItemsSource="{Binding SecondLevel}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Text="{Binding FirstLevel.Id}" Margin="10,0,0,0" Foreground="#FF03577A" FontWeight="Bold" />
                <TextBlock Text="-" Margin="5,0,0,0" Foreground="#FF03577A" FontWeight="Bold"/>
                <TextBlock Text="{Binding FirstLevel.FirstName}" Margin="5,0,0,0" FontWeight="Bold" Foreground="#FF03577A" />
                <TextBlock Text="{Binding FirstLevel.LastName}" Margin="5,0,0,0" FontWeight="Bold" Foreground="#FF03577A" />
            </StackPanel>
        </HierarchicalDataTemplate>
        <HierarchicalDataTemplate DataType="{x:Type converter:BusinessCaseTreeViewModelSecond}" ItemsSource="{Binding  BusinessCases}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Text="{Binding SecondLevel.Id}" Margin="10,0,0,0" Foreground="#FF095A7C" FontWeight="Bold" />
                <TextBlock Text="-" Margin="5,0,0,0" Foreground="#FF095A7C" FontWeight="Bold"/>
                <TextBlock Text="{Binding SecondLevel.FirstName}" Margin="5,0,0,0" FontWeight="Bold" Foreground="#FF095A7C" />
                <TextBlock Text="{Binding SecondLevel.LastName}" Margin="5,0,0,0" FontWeight="Bold" Foreground="#FF095A7C" />
            </StackPanel>
        </HierarchicalDataTemplate>
        <DataTemplate DataType="{x:Type business:BusinessCase}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Text="(" Margin="10,0,0,0" Foreground="#FF0B89BD" FontWeight="Bold" />
                <TextBlock Text="{Binding Id}" Margin="1,0,0,0" Foreground="#FF0B89BD" FontWeight="Bold" />
                <TextBlock Text=")" Margin="2,0,0,0" Foreground="#FF0B89BD" FontWeight="Bold"/>
                <TextBlock Text="{Binding CreationDate, StringFormat='{}{0:dd MMMM yyyy}'}" Margin="5,0,0,0" Foreground="#FF0B89BD" />
                <TextBlock Text="-" Margin="5,0,0,0" Foreground="#FF0B89BD" FontWeight="Bold"/>
                <TextBlock Text="{Binding ClosureDate, StringFormat={}{0:dd MMMM yyyy}}" Margin="5,0,0,0" Foreground="#FF0B89BD" />
            </StackPanel>
        </DataTemplate>
    </TreeView.Resources>
</TreeView>

I never arrive on the IsSelected setter in my ViewModel. If you have any idea, there are welcomed.

Thanks in advance

Answer 1

It might have something to do with the fact you're doing it in ItemContainerStyle. Also, make sure IsSelected is in all of the types being added to the treeview

Try this:

<TreeView>
    <TreeView.Resources>
        <Style TargetType="{x:Type TreeViewItem}">
            <Setter Property="IsSelected"
                    Value="{Binding IsSelected, Mode=TwoWay}" />
        </Style>
    </TreeView.Resources>
    .....
</TreeView>