xaml中的Android原生视图不显示在Xamarin.Forms中

public class NativeAndroidView : View
{
    public static readonly BindableProperty NativeViewProperty = BindableProperty.Create(
        nameof(NativeView),
        typeof(Android.Views.View),
        typeof(NativeAndroidView),
        null);

    public Android.Views.View NativeView
    {
        get { return (Android.Views.View)GetValue(NativeViewProperty); }
        set { SetValue(NativeViewProperty, value); }
    }
}

[assembly: ExportRenderer(typeof(NativeAndroidView), typeof(NativeAndroidViewRenderer))]
namespace YourNamespace.Droid
{
    public class NativeAndroidViewRenderer : ViewRenderer<NativeAndroidView, Android.Views.View>
    {
        protected override void OnElementChanged(ElementChangedEventArgs<NativeAndroidView> e)
        {
            base.OnElementChanged(e);

            if (Control == null)
            {
                // 创建Android原生视图
                var nativeView = new Android.Views.View(Context);

                // 将Android原生视图与自定义控件关联
                SetNativeControl(nativeView);
            }
        }
    }
}

<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>
        <local:NativeAndroidView>
            <local:NativeAndroidView.NativeView>
                <!-- 在这里放置Android原生视图 -->
            </local:NativeAndroidView.NativeView>
        </local:NativeAndroidView>
    </StackLayout>
</ContentPage>