Blank space at the end of menu item

[sharethl]

Hi

1. Does any one know why there is a blank at the end of menuItem?
How to make full use of menu item's space?
Change Grid.Width doesn't help.

2. When click non-buttons area of first menu item (like rectangle area), how to avoid context menu disappear?

Attached a picture and code.
Thanks

<ContextMenu x:Key="RightClickMenu" >
             <Grid Width="200">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition/>
                        <ColumnDefinition/>
                        <ColumnDefinition/>
                        <ColumnDefinition/>
                    </Grid.ColumnDefinitions>
                <Label Grid.Column="0" Width="30" Content="ID"/>
                <ComboBox Grid.Column="1" Width="60" x:Name="cbID" Loaded="OnIDComboboxLoaded" />
                <Button Grid.Column="2" Width="60" x:Name="btnChangeID" Content="Change" Click="OnChangeIDButtonID_Click"/>
                <Button Grid.Column="3" Width="60" x:Name="btnClearID" Content="Clear ID"/>
            </Grid>
</ContextMenu>

[Lightning]

First thing I would try is to set the width of the columns (in the columndefinition), second thing you could change is the width of the contextmenu.

[sharethl]

I add a width property to Contextmenu, 250,
see the second item, right side triangle can not be seem but it is still there.

First thing I would try is to set the width of the columns (in the columndefinition), second thing you could change is the width of the contextmenu.