pass contextmenu parent as CommandParameter

问题

i have a HierarchicalDataTemplate for a TreeViewItem, in the template i have a contextmenu and i want to pass as CommandParameter the ContextMenu parent - i.e the TreeViewItem owner that was right clicked at the moment, is there a way to do that? here is my template:

    <HierarchicalDataTemplate 
    x:Key="ServerTemplate"
    DataType="{x:Type models:Server}" 
    ItemsSource="{Binding Channels}"
    ItemTemplate="{StaticResource ChannelTemplate}">
    <StackPanel
        Tag="{Binding DataContext,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type Window}}}"
        Orientation="Horizontal">
        <StackPanel.ContextMenu>
            <ContextMenu
                FontSize="14"
                FontFamily="Arial">
                <MenuItem 
                    Header="{x:Static p:Resources.ServerOperations_CommunicationSettings}"
                    Command="{Binding PlacementTarget.Tag.ServerCommunicationSettingCommand, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type ContextMenu}}}"
                    CommandParameter="{Binding Path=Parent, RelativeSource={RelativeSource Mode=Self}}">
                </MenuItem>

            </ContextMenu>
        </StackPanel.ContextMenu>
        <Image 
            Source="{Binding ImageURL, Converter={StaticResource StringToImageConverter}}"
            Margin="0,0,2,0"
            Height="25"
            Width="25"/>
        <TextBlock 
            Text="{Binding ServerName}"
            Foreground="White"/>
    </StackPanel>
</HierarchicalDataTemplate>

thanks for the help

回答1:

You can get the TreeViewItem by getting PlacementTarget of ContextMenu which will be StackPanel and its TemplatedParent will be ContentPresenter and its TemplatedParent will be TreeViewItem. So this will work:

CommandParameter="{Binding Path=PlacementTarget.TemplatedParent.TemplatedParent, 
                           RelativeSource={RelativeSource Mode=FindAncestor,
                                            AncestorType={x:Type ContextMenu}}}"

PlacementTarget (StackPanel) --> TemplatedParent (ContentPresenter) --> TemplatedParent (TreeViewItem)

Ideally it's not a good idea to pass UI components to ViewModel. You should pass data i.e. DataContext of TreeViewItem as you can always play with that.

In case you want to pass Server instance i.e. DataContext of TreeviewItem, you can simply do "{Binding}" since MenuItem will inherit it from StackPanel.

CommandParameter="{Binding}"

来源：https://stackoverflow.com/questions/22448749/pass-contextmenu-parent-as-commandparameter

标签

wpf

contextmenu

treeviewitem

commandparameter