使用HierarchicalDataTemplate将ContextMenu添加到TreeView

Question

I want to add a contextmenu to a TreeView. This I can do by the following code:

<TreeView x:Name="treeView" Grid.Row="1" Grid.Column="0" ItemsSource="{Binding Classes}"
              commandBehaviors:MouseDoubleClick.Command="{Binding TreeMouseDoubleClick}"
              commandBehaviors:MouseDoubleClick.CommandParameter="{Binding ElementName=treeView, Path=SelectedItem}"
              Margin="3,3,3,3" ContextMenu="{Binding ContextMenu, Mode=OneWay}">
...

My TreeView only have two levels. Class and Pupil.

My problem now is, that I have a HierarchicalDataTemplate for my TreeView and I only want to show the contextMenu if the right-click is on a class-node

This looks like

<HierarchicalDataTemplate DataType="{x:Type Entity:Class}" ItemsSource="{Binding Pupils}">
                <Label Content="{Binding Name}"/>
            </HierarchicalDataTemplate>
            <DataTemplate DataType="{x:Type Entity:Pupil}">
                <Label Margin="0">
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition Width="Auto"/>
                        </Grid.ColumnDefinitions>
                        <Label Grid.Column="0" Content="{Binding Lastname}" Margin="0"/>
                        <Label Grid.Column="1" Content="{Binding Firstname}" Margin="0"/>
                    </Grid>
                </Label>
            </DataTemplate>

How can I solve this?

Answer 1

I suggest adding a view-model to wrap your Class type, and creating a property on it for the ContextMenu. Instantiate these view-models to wrap each Class type, and change the DataType in your HierarchicalDataTemplate to be the new view-model's type. Then, the label in your HierarchicalDataTemplate can bind to the ContextMenu property, and you can remove the ContextMenu binding off your TreeView. It will show on Class objects, but not on Pupil objects.