确保为WebView指定布局选项。

<ContentPage.Content>
    <ScrollView> <!-- ScrollView not needed as WebView has inbuilt scrolling behavior -->
        <StackLayout Spacing="10" Margin="20">
           <WebView x:Name="Browser" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" />
        </StackLayout>
    </ScrollView>
</ContentPage.Content>

Xamarin在某个时候更新了label元素，更新包括在label元素中显示HTML的方法，通过添加TextType="Html"到元素中。

• • 示例：**

<Label TextType="Html">
    <![CDATA[
    This is <strong style="color:red">HTML</strong> text.
    ]]>
</Label>

• （来源：https：//learn.microsoft.com/en-us/xamarin/xamarin-forms/用户界面/文本/标签#显示-html）*

webview可以单独在ContentPage.Content中。不需要将其 Package 在ScrollView或StackLayout中。此方法也不需要指定水平或垂直选项。

<ContentPage.Content>
    <WebView x:Name="Browser" />
</ContentPage.Content>

使用webBrowser尝试此操作

public MainPage()
    {
        InitializeComponent();
        CheckWifiOnStart();
        CheckWifiContinously();
    }

    private void CheckWifiOnStart()
    {
        var source = new HtmlWebViewSource();
        source.BaseUrl = "file://android_asset/";

        //CONTROL TO SEE IF USER IS CONNECTED 
        if (!CrossConnectivity.Current.IsConnected)
        {
            Browser.Source = "file:///android_asset/index.html";
        }
        else
        {
            Browser.Source = "ONLINE URL";
        }
    }

    private void CheckWifiContinously()
    {
        var source = new HtmlWebViewSource();
        source.BaseUrl = "file://android_asset/";

        //CONTROL TO CONNECTIVITY CHANGE
        CrossConnectivity.Current.ConnectivityChanged += (sender, args) => {

            if (!CrossConnectivity.Current.IsConnected)
            {
                DisplayAlert("ERROR", "OFFLINE MODE", "OK");
                Browser.Source = "file:///android_asset/index.html";
            }
            else
            {
                DisplayAlert("INTERNET DETECTED", "ONLINE MODE", "OK");
                Browser.Source = "ONLINE URL";
            }          
        };
    }

    public interface IBaseUrl { string GetFile(); }