如何在.xaml文件中从Xamarin Forms中获取跨平台应用程序中的可用屏幕大小值？

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:YourNamespace"
             x:Class="YourNamespace.YourPage">
    <StackLayout>
        <Label Text="屏幕宽度：" />
        <Label Text="{Binding ScreenWidth}" />
        <Label Text="屏幕高度：" />
        <Label Text="{Binding ScreenHeight}" />
    </StackLayout>
</ContentPage>

using Xamarin.Forms;

namespace YourNamespace
{
    public partial class YourPage : ContentPage
    {
        public double ScreenWidth { get; set; }
        public double ScreenHeight { get; set; }

        public YourPage()
        {
            InitializeComponent();

            ScreenWidth = DeviceDisplay.MainDisplayInfo.Width;
            ScreenHeight = DeviceDisplay.MainDisplayInfo.Height;

            BindingContext = this;
        }
    }
}