Xamarin形成贝壳覆盖层

我需要一些建议。我正在尝试创建自己的shell渲染 ShellOverlay 这占据了整个显示空间,请看图片,这在Android10中有效,但在Android11中不起作用。

有人会知道错误在哪里。

在这张图片中,ShellOverlay内容被填充到整个屏幕上。内容位于状态栏和导航栏下

安卓10:

安卓11: ShellOverlay的内容不会通过状态栏重叠

主要活动。反恐精英

 if (Build.VERSION.SdkInt >= BuildVersionCodes.Lollipop)
 {
     Window.AddFlags(WindowManagerFlags.LayoutNoLimits);
     Window?.SetFlags(WindowManagerFlags.LayoutNoLimits, WindowManagerFlags.LayoutNoLimits);
 }

ShellOverlay渲染器

public class CustomShellRenderer : ShellRenderer
{
    public CustomShellRenderer(Context context) : base(context)
    {
    }

    protected override IShellItemRenderer CreateShellItemRenderer(ShellItem shellItem)
    {
        return new CustomShellItemRenderer(this);
    }
   
}

public class CustomShellItemRenderer : ShellItemRenderer
{
    FrameLayout shellOverlay;
    View outerlayout;
    BottomNavigationView bottomView;
    IVisualElementRenderer viewRenderer;

    public CustomShellItemRenderer(IShellContext shellContext) : base(shellContext)
    {
    }

    public override Android.Views.View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        outerlayout = base.OnCreateView(inflater, container, savedInstanceState);
        bottomView = outerlayout.FindViewById<BottomNavigationView>(Resource.Id.bottomtab_tabbar);
        shellOverlay = outerlayout.FindViewById<FrameLayout>(Resource.Id.bottomtab_tabbar_container);

        if (ShellItem is ShellOverlay overlay && overlay.Content != null)
            SetupOverlay();

        return outerlayout;
    }

    private void SetupOverlay()
    {
        var overlay = (ShellOverlay)ShellItem;

        bottomView.Measure((int)MeasureSpecMode.Unspecified, (int)MeasureSpecMode.Unspecified);

        outerlayout.Measure((int)MeasureSpecMode.Unspecified, (int)MeasureSpecMode.Unspecified);

        shellOverlay.RemoveAllViews();
        shellOverlay.AddView(ConvertFormsToNative(overlay.Content,
            new Xamarin.Forms.Rectangle(0, 0, Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Width / Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Density, Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Height / Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Density)));
    }

    public override void OnConfigurationChanged(Configuration newConfig)
    {
        base.OnConfigurationChanged(newConfig);

        SetupOverlay();
    }

    private View ConvertFormsToNative(Xamarin.Forms.View view, Xamarin.Forms.Rectangle size)
    {
        viewRenderer = Platform.CreateRendererWithContext(view, Context);
        var viewGroup = viewRenderer.View;
        viewRenderer.Tracker.UpdateLayout();

        if (view.HeightRequest > 0)
            size.Height = view.HeightRequest;

        var layoutParams = new ViewGroup.LayoutParams((int)(size.Width * Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Density), (int)(size.Height * Xamarin.Essentials.DeviceDisplay.MainDisplayInfo.Density));
        viewGroup.LayoutParameters = layoutParams;
        view.Layout(size);
        viewGroup.Layout(0, 0, (int)view.Width, (int)view.Height);
        return viewGroup;
    }
}

布局/底部布局。xml

<?xml version="1.0" encoding="utf-8" ?>  

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent">

<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/bottomtab.navarea"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_gravity="fill"
        android:layout_weight="1" />
    
    <com.google.android.material.bottomnavigation.BottomNavigationView 
        android:id="@+id/bottomtab.tabbar"
        android:theme="@style/Widget.Design.BottomNavigationView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

<FrameLayout
    android:id="@+id/bottomtab.tabbar.container"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal|bottom" />
    
</FrameLayout>

控制壳覆盖

public class ShellOverlay : ShellItem
{
    public View Content { get; set; }
}

AppShell。xaml

<Shell xmlns="http://xamarin.com/schemas/2014/forms" 
   xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
   xmlns:shellOverlay="clr-namespace:ShellOverLayTest.Views.Controls.ShellOverlay;assembly=ShellOverLayTest"
   Title="ShellOverLayTest"
   x:Class="ShellOverLayTest.AppShell"
   Shell.FlyoutBehavior="Disabled"
   Shell.TabBarIsVisible="False"
   Shell.NavBarIsVisible="False">

<shellOverlay:ShellOverlay x:Name="Overlay">
    <shellOverlay:ShellOverlay.Content>
        <Grid x:Name="GridRoot"  
              VerticalOptions="FillAndExpand"
              HorizontalOptions="FillAndExpand" 
              BackgroundColor="Red">

        </Grid>
    </shellOverlay:ShellOverlay.Content>
</shellOverlay:ShellOverlay>

AppShell。反恐精英

 public AppShell()
 {
    InitializeComponent();
    Overlay.Items.Add(new ShellContent { Route = nameof(MainPage), ContentTemplate = new DataTemplate(typeof(MainPage)) });
 }

谢谢