Label visibility true when entry text property is not empty

Hello Guy's

      I have a create application but i am facing a issue.
      I want to label visibility true when entry text property is not empty and when entry text property not empty then label visibility false.
      I want to do this thing only Xaml page not Cs. page.

         <StackLayout  Grid.Row="1" Orientation="Vertical" BackgroundColor="Transparent" Spacing="10">
                <Label x:Name="lblUserName" Text="User ID" FontSize="Medium" TextColor="White" />
               <Entry x:Name="enrtyUserName" Placeholder="User ID" FontSize="Medium" PlaceholderColor="Gray" BackgroundColor="White" />
        </StackLayout>

Is it possible in xaml coding use like value converter or triggers.

Thanks in advance