.NET 5显示WebView2

Question

我试图在WebView2 5上的Xamarin应用程序中显示一个.NET。

因此，在启动时，我将MainPage设置为Navigator，如下所示：

Navigator.xaml:

<?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:local="clr-namespace:XamTestNET5.Views"
             x:Class="XamTestNET5.Navigator" Title="Here is a title">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="Auto"></RowDefinition>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <StackLayout Grid.Row="0" Grid.Column="0" Orientation="Vertical" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
            <Label FontSize="Medium">Hello</Label>
            <!--<local:PlaceHolderView></local:PlaceHolderView>-->
            <local:CustomWebBrowserView x:Name="browser" Source="https://www.google.com"></local:CustomWebBrowserView>
        </StackLayout>
        <StackLayout Grid.Row="1" Grid.Column="0" Orientation="Horizontal" HorizontalOptions="FillAndExpand" BackgroundColor="{StaticResource Primary}">
            <Button FontSize="Large" Text="Tab 1" BorderWidth="0" BorderColor="Transparent"></Button>
            <Button FontSize="Large" Text="Tab 2" BorderWidth="0" BorderColor="Transparent"></Button>
            <Button FontSize="Large" Text="Tab 3" BorderWidth="0" BorderColor="Transparent"></Button>
        </StackLayout>
    </Grid>
</ContentPage>

CustomWebBrowserView.xaml:

<?xml version="1.0" encoding="UTF-8"?>
<ContentView xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="XamTestNET5.Views.CustomWebBrowserView">
  <ContentView.Content>
        <Grid></Grid>
  </ContentView.Content>
</ContentView>

CustomWebBrowserView.xaml.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace XamTestNET5.Views
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class CustomWebBrowserView : ContentView
    {
        public static readonly BindableProperty SourceProperty = BindableProperty.Create(
          propertyName: "Source",
          returnType: typeof(string),
          declaringType: typeof(string),
          defaultValue: "");

        public string Source
        {
            get { return (string)GetValue(SourceProperty); }
            set { SetValue(SourceProperty, value); }
        }
        public CustomWebBrowserView()
        {
            InitializeComponent();
        }
    }
}

WPF项目中的WebBrowserRenderer.cs：

using Microsoft.Web.WebView2.Core;
using Microsoft.Web.WebView2.Wpf;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms.Platform.WPF;
using XamTestNET5.Views;
using XamTestNET5WPF.Renderers;

[assembly: ExportRenderer(typeof(CustomWebBrowserView), typeof(WebBrowserRenderer))]
namespace XamTestNET5WPF.Renderers
{
    public class WebBrowserRenderer : ViewRenderer<CustomWebBrowserView, WebView2>
    {
        WebView2 webView;
        CoreWebView2EnvironmentOptions options = new CoreWebView2EnvironmentOptions();
        CoreWebView2Environment env;
        String userDataFolder = Path.GetTempPath();

        public WebBrowserRenderer() : base()
        {
        }

        private void WebView_CoreWebView2Ready(object sender, EventArgs e)
        {
            this.webView.CoreWebView2.Navigate(@"https://www.bing.com");
        }

        protected async override void OnElementChanged(ElementChangedEventArgs<CustomWebBrowserView> e)
        {
            base.OnElementChanged(e);
            if (e.NewElement != null)
            {
                webView = new WebView2();
                env = await CoreWebView2Environment.CreateAsync("", userDataFolder, options);
                webView.CoreWebView2Ready += WebView_CoreWebView2Ready;
                webView.Source = new Uri(@"https://www.bing.com");
                webView.Visibility = System.Windows.Visibility.Visible;
                this.SetNativeControl(webView);
                await webView.EnsureCoreWebView2Async(env);
            }
        }

        protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            base.OnElementPropertyChanged(sender, e);
            if (e.PropertyName == nameof(CustomWebBrowserView.SourceProperty))
            {
                this.webView.Source = new Uri(Element.Source);
                this.webView.CoreWebView2.Navigate(Element.Source);
            }
        }
    }
}

通过调试，我可以看到我得到的是WebView2，但是它抹掉了内容页，只留下了标题。

如果我注释掉CustomWebBrowserView并放入一个PlaceHolderView存根，它看起来就像这样：

<?xml version="1.0" encoding="UTF-8"?>
<ContentView xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="XamTestNET5.Views.PlaceHolderView">
  <ContentView.Content>
      <StackLayout>
          <Label Text="Placeholder" />
      </StackLayout>
  </ContentView.Content>
</ContentView>

布局至少没有被抹掉，但当然没有WebView2。

我也不能让壳牌正常工作，但这是意料之中的：https://github.com/xamarin/Xamarin.Forms/issues/7377

因此，我认为在此期间的解决办法可能只是在应用程序中创建自己的自定义导航，但我想在WPF中提供WebView2控件。我在WebBrowserRenderer或Xaml中做错什么了吗？

Answer 1

将CustomWebBrowserView更改为以下内容，基于视图而不是基于ContentView，现在一切都正常工作，而视图没有被抹掉：

CustomWebBrowserView.Xaml:

<?xml version="1.0" encoding="UTF-8"?>
<View xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="XamTestNET5.Views.CustomWebBrowserView">
</View>

CustomWebBrowserView.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace XamTestNET5.Views
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class CustomWebBrowserView : View
    {
        public static readonly BindableProperty SourceProperty = BindableProperty.Create(
          propertyName: "Source",
          returnType: typeof(string),
          declaringType: typeof(string),
          defaultValue: "");

        public string Source
        {
            get { return (string)GetValue(SourceProperty); }
            set { SetValue(SourceProperty, value); }
        }
        public CustomWebBrowserView()
        {
            InitializeComponent();
        }
    }
}

Navigator.xaml:

    <StackLayout Grid.Row="0" Grid.Column="0" Orientation="Vertical" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
        <Label FontSize="Medium">Hello</Label>
        <!--<local:PlaceHolderView></local:PlaceHolderView>-->
        <local:CustomWebBrowserView HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" x:Name="browser" Source="https://www.sneauxkones.com"></local:CustomWebBrowserView>
    </StackLayout>