ios - iOS 11.1.2 上的 Xamarin.Forms : Webview loads a bigger font

Question

我正在使用 Xamarin.Forms 加载互联网网页(客户的要求，请不要评判我)，问题是在 iOS 中网页看起来比实际更大。

我在 iOS 上没有任何自定义渲染。

这是在 iPhone 6 iOS 11.1.2 的 safari 上加载的网站

这里是在 webview 上加载的

主页.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:Juppie"
             x:Class="Juppie.MainPage">
             <Grid>

    <WebView x:Name="Navegador" Source="http://empleosapp.caonainteractive.com/" 
    WidthRequest="1000" HeightRequest="1000" IsVisible="{Binding Path=HayInternet}" ></WebView>
    <ActivityIndicator IsRunning="{Binding Path=Navegando}" IsVisible="{Binding Path=Navegando}"
        VerticalOptions="CenterAndExpand"
                               HorizontalOptions="CenterAndExpand"
                               RelativeLayout.XConstraint="{ConstraintExpression Type=RelativeToParent,
                                        Property=Height,
                                        Factor=0.33}"
                               RelativeLayout.YConstraint="{ConstraintExpression Type=RelativeToParent,
                                        Property=Height,
                                        Factor=0.33}"/>
    </Grid>


</ContentPage>

MainPage.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using Plugin.Connectivity;
using System.ComponentModel;

namespace Juppie
{
    public partial class MainPage : ContentPage, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        public MainPage()
        {
            InitializeComponent();

            Navegador.Navigating += Navegador_Navigating;
            Navegador.Navigated += (sender, e) => { Navegando = false; };
            HayInternet = true;
            BindingContext = this;
        }
        bool hayInternet;

        public bool HayInternet
        {
            get
            {
                return hayInternet;
            }

            set
            {
                hayInternet = value;

                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("HayInternet"));

                EvaluarInternet();
            }
        }
        bool navegando;

        public bool Navegando
        {
            get
            {
                return navegando;
            }

            set
            {
                navegando = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Navegando"));

            }
        }

        public async void EvaluarInternet(){
            if (!HayInternet)
            {
             await DisplayAlert("Aviso","Se requiere conexion a internet para emplear esta aplicacion", "OK");
            }
        }

        protected override void OnAppearing()
        {
            HayInternet = CrossConnectivity.IsSupported && CrossConnectivity.Current.IsConnected;

            CrossConnectivity.Current.ConnectivityChanged += (sender, args) =>
            {
                HayInternet = args.IsConnected;
            };

            base.OnAppearing();
        }

        protected override bool OnBackButtonPressed()
        {
            if (Navegador.CanGoBack)
            {
                Navegador.GoBack();
                return false;
            }

            return base.OnBackButtonPressed();
        }

        void Navegador_Navigating(object sender, WebNavigatingEventArgs e)
        {
            Navegando = true;
            if (e.Url.Contains("/banner"))
            {
                e.Cancel = true;

                var uri = new Uri(e.Url.Replace("/banner", ""));
                Device.OpenUri(uri);
            }
        }
    }
}

我尝试使用自定义渲染并设置 scalePageToFit = false，但没有成功。如果有人知道我该如何解决这个问题，请告诉我。

Answer 1

Xaml:- VerticalOptions="FillAndExpand" 似乎满足 WebView 的 HeightRequest 和 WidthRequest 属性规范要求在 StackLayout 中呈现 - 在 Grid 中它似乎无论如何都会呈现:

<Grid>
    <WebView x:Name="webView"
             VerticalOptions="FillAndExpand"
             Source="https://www.xamarin.com/"/>
</Grid>

渲染器，ScalesPageToFit 默认为 false(至少在 iPhone SE 11.2 的模拟器中是这样)

[assembly: ExportRenderer(typeof(WebView), typeof(MyWebViewRenderer))]
namespace MyNamespace.iOS
{
    public class MyWebViewRenderer : WebViewRenderer
    {
        protected override void OnElementChanged(VisualElementChangedEventArgs e)
        {
            base.OnElementChanged(e);

            if (NativeView != null && e.NewElement != null)
            {
                var webView = ((UIWebView)NativeView);
                webView.ScalesPageToFit = true;
            }
        }
    }
}

下面的屏幕截图来自 iPhone SE 的模拟器。

ScalesPageToFit = true:

ScalesPageToFit = false: