CODEWITHSUNDEEP
c#wpflistboxcontextmenu
Pavel Maskevich
Pavel Maskevich

Reputation: 505

Set PlacementTarget of ContextMenu opening via keyboard WPF

I can's set PlacementTarget for ContextMenu. It is always opened (via Shift+F10) in the center of listbox.

I tried:

private void listBox_PreviewKeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
  if (e.KeyboardDevice.Modifiers == ModifierKeys.Shift && 
      (e.Key == Key.F10 || e.SystemKey == Key.F10)){
       var listBox = sender as System.Windows.Controls.ListBox;
       listBox.ContextMenu.PlacementTarget = listBox.ItemContainerGenerator.ContainerFromItem(listBox.SelectedItem) as ListBoxItem;
  }
}

and 

private void listBox_ContextMenuOpening(object sender, ContextMenuEventArgs e)
{
   var listBox = sender as System.Windows.Controls.ListBox;
   listBox.ContextMenu.PlacementTarget = listBox.ItemContainerGenerator.ContainerFromItem(listBox.SelectedItem) as ListBoxItem;
}

But it still doesn't work as expected. (I expect it is shown in the center of selected itemlistbox)

Any suggestions?

Upvotes: 0

Views: 615

Answers (1)

King King
King King

Reputation: 63377

I've just tried your code. The problem is you cannot change the PlacementTarget of the the ContextMenu once it is set to the ListBox. That means the ListBox is always set as PlacementTarget of the ContextMenu. I understand that that ContextMenu is in fact used for the selected item. So why not set it for each item? Then it works expectedly. Try this:

<ListBox ItemsSource="some_source_here"/>
        <ListBox.ItemContainerStyle>
            <Style TargetType="ListBoxItem">
                <Setter Property="ContextMenu">
                    <Setter.Value>
                        <!-- your ContextMenu here -->
                    </Setter.Value>
                </Setter>
            </Style>
        </ListBox.ItemContainerStyle>            
</ListBox>

There is not any code behind involved here. Just change your XAML like above.

Upvotes: 1

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