xamarin visual iOS自定义进度条和web容器

我们一直在为Android和iOS开发Xamarin应用程序，它在Android上运行得非常好，但在自定义动态进度条和从web容器切换回主页方面存在一个非常奇怪的问题

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当切换到简介时，我不明白你到底想做什么。你能展示一下在Android上运行的正确效果吗？您可以显示gif或显示Android代码，我可以对其进行测试。

namespace CustomApp
{
[XamlCompilation(XamlCompilationOptions.Compile)] 
public partial class Homepage : ContentPage
{

    static MyProgressBar progressbar1;
    static MyProgressBar progressbar2;

    public Homepage()
    {
        InitializeComponent();
        addprogressbars();
    }


    void addprogressbars()
    {
        Device.BeginInvokeThread() =>
        {
            MainGrid.Children.Add(progressbar1 = new MyProgressBar()
            {
                VerticalOptions = LayoutOptions.Start,
                HorizontalOptions = LayoutOptions.Fill


            }, 1, 7);

        Grid.SetColumnSpan(progressbar1, 1);
        progressbar1.Progress = App._level1;

        MainGrid.Children.Add(progressbar2 = new MyProgressBar()
        {
            VerticalOptions = LayoutOptions.Start,
            HorizontalOptions = LayoutOptions.Fill

        }, 4, 7);
        Grid.SetColumnSpan(progressbar2, 1);
        progressbar2.Progress = App._level2;
        
        }
    
    }

    protected override void OnAppearing()
    {
        base.OnAppearing();
        addprogressbars()
    }


    async void Accountspage(object sender, System.EventArgs args)
    {
      await Navigation.PushAsync(new accountpage());
    }
    async void Settingspage(object sender, System.EventArgs args)
    {
       await Navigation.PushAsync(new settingspage());
    }
    async void webcontpagea1(object sender, System.EventArgs args)
    {
        await Navigation.PushAsync(new webcontainer_001());
    }
    async void webcontpagea2(object sender, System.EventArgs args)
    {
       await Navigation.PushAsync(new webcontainer_002());

    }
}

[assembly: ExportRenderer(typeof(MyProgressBar), typeof(MyProgressBarRenderer))] 
namespace Custom_GeoPHEV.iOS
{

public class MyProgressBarRenderer : ProgressBarRenderer
{
    protected override void OnElementChanged(
     ElementChangedEventArgs<Xamarin.Forms.ProgressBar> e)
    {
        base.OnElementChanged(e);
        if (Control != null)
        {
            Control.Progress = (int)0.5;
           // Control.ScaleY = 5; //Changes the height
        }

        Control.ProgressTintColor = Color.FromRgb(2,118, 179).ToUIColor(); 
        Control.TrackTintColor = Color.FromRgb(0,0,0).ToUIColor();
    }

    public async override void LayoutSubviews()
    {
        await Task.Delay(0);
        base.LayoutSubviews();
        // this was 18.5
        CGAffineTransform transform = CGAffineTransform.MakeScale(1.2f, 10f);

        transform.TransformSize(this.Frame.Size);
        this.Transform = transform;
        this.ClipsToBounds = true;
        this.Layer.MasksToBounds = true;

    }
}

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
         xmlns:d="http://xamarin.com/schemas/2014/forms/design"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         NavigationPage.HasNavigationBar="False"
         mc:Ignorable="d"
         x:Class="Custom_webcontrainer.page001"
         Title="Trips"
        >

<ContentPage.Content>
    <Grid HorizontalOptions="CenterAndExpand" RowSpacing="0" ColumnSpacing="0">
    </Grid>
</ContentPage.Content>
</ContentPage>