Question

I’m working on a WPF application and I’m using the MVVM pattern. I use MVVMLight to help me handle some Events. I need to forward the “Click” event so that I can pass the arguments as well so that I can know for sure which item that sent the event. If I use the “Command” I cant know for sure that it was the selected item that sent the event – as the item doesnt need to be selected to right click on it.

This is my code for displaying a list of “order lines”. There are two types of order lines, and for one of the data types; “AccessoryOrderLine” – I want to add a context menu.

My problem is that I cannot access my Window’s DataContext. I’ve named the root node in the Window “root”, and I’m trying to access the root’s DataContext, but this failes with the following error:

System.Windows.Data Error: 4 : Cannot find source for binding with
reference ‘ElementName=root’.
BindingExpression:Path=DataContext.PackAccessory; DataItem=null;
target element is ‘EventToCommand’ (HashCode=5903270); target property
is ‘Command’ (type ‘ICommand’)

<ListBox HorizontalContentAlignment="Stretch" Margin="10,0,10,10" DockPanel.Dock="Bottom" Grid.Row="1" ItemsSource="{Binding OrderLines, NotifyOnSourceUpdated=True, NotifyOnTargetUpdated=True, UpdateSourceTrigger=PropertyChanged}">
    <ListBox.Resources>
        <DataTemplate DataType="{x:Type m:UnitOrderLine}">
             <v:OrderLine />
        </DataTemplate>
        <DataTemplate DataType="{x:Type m:AccessoryOrderLine}">
            <v:OrderLine>
                <v:OrderLine.ContextMenu>
                    <ContextMenu>
                        <MenuItem Header="Pack 1" IsCheckable="False">
                            <i:Interaction.Triggers>
                                <i:EventTrigger EventName="Click">
                                    <cmd:EventToCommand Command="{Binding ElementName=root, Path=DataContext.PackAccessory }" PassEventArgsToCommand="True" />
                                </i:EventTrigger>
                            </i:Interaction.Triggers>
                         </MenuItem>
                     </ContextMenu>
                 </v:OrderLine.ContextMenu>
             </v:OrderLine>
         </DataTemplate>
     </ListBox.Resources>
 </ListBox>

I’ve also tried to use “TemplatedParent” and then I get access to my “OrderLine” DataContext, but I cant get one step further back to my “MainWindowModel”.

http://www.thomaslevesque.com/2011/03/21/wpf-how-to-bind-to-data-when-the-datacontext-is-not-inherited/

Found a solution to my problem 🙂

Answer 1

Found a solution. Updated my original post with the link to my solution.