如何将表格背景设置为便携式跨平台Xamarin表格的透明度?

我正在使用便携式xamarin跨平台.我有两个项目android和IOS.

I am using Portable xamarin cross platform. I have two project android and IOS.

我必须使表格成为透明表格.我已经编写了相同的代码，并且此代码可以在android中完美运行，但不能在iOS中运行

I have to make form as transparent form. I have written code for same and this code perfectly working in android but not in IOS

下面是我的代码:

  <ContentPage BackgroundColor="#00000000">

        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="180"></RowDefinition>
                <RowDefinition Height="*"></RowDefinition>
                <RowDefinition Height="200"></RowDefinition>
            </Grid.RowDefinitions>

            <StackLayout Grid.Row="0" VerticalOptions="StartAndExpand" HorizontalOptions="FillAndExpand" BackgroundColor="#80000000" HeightRequest="175" >

            </StackLayout>

            <BoxView HeightRequest="200" Grid.Row="1"></BoxView>

            <StackLayout VerticalOptions="End" HorizontalOptions="FillAndExpand"  BackgroundColor="#80000000" HeightRequest="160"  Grid.Row="2" >
                <Label Text="05:00" FontSize="60" FontAttributes="Bold" TextColor="White" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" ></Label>
            </StackLayout>
        </Grid>  

   </ContentPage>

以下是android屏幕截图:

下面是IOS ScreenShot:

请建议我该怎么做才能在两个平台上都具有透明性表格

Please suggest me what to do to have transparency form in both platform

预先感谢