Question

Let’s say i got this ContextMenu:

<Style x:Key="{x:Type ContextMenu}" TargetType="{x:Type ContextMenu}">
    <Setter Property="VerticalOffset" Value="-10"/>
    <Setter Property="HorizontalOffset" Value="-10"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ContextMenu}">
                <Border Background="Transparent">
                    <Border.Effect>
                        <DropShadowEffect BlurRadius="10" ShadowDepth="0" Opacity="0.5"/>
                    </Border.Effect>
                    <Border Margin="10" Style="{StaticResource MenuBorderStyle}">
                        <Grid x:Name="SubMenu" Grid.IsSharedSizeScope="True">
                            <!-- StackPanel holds children of the menu. This is set by IsItemsHost=True -->
                            <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle"/>
                        </Grid>
                    </Border>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

So as you can see, i offset the appearance of the menu by 10 pixels to the top and to the left, getting the top-left corner of the ContextMenu to be right under the cursor.

In fact, because of Border‘s margin of 10 pixels, the whole control shoule be more left-top than a cursor, because the control it self starts with a shadow.

And, as you can have guessed, when the context menu appears not on the bottom-right side of the cursor (say the cursor is near bottom or left side of the screen), the offset needs to be changed to an opposite (by either either X or Y or both coordinates).

The question is how to do that by xaml?

(sorry for my english)

Answer 1

Try setting Placement property to AbsolutePoint. Check this out as well, it might help you.