How to zoom the webview in xamarin? - xamarin

Question

I couldn't zoom the webview in Xamarin. Below is the coding, can someone help me please. Thank you
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="highchart.MainPage">
<ScrollView>
<WebView VerticalOptions="FillAndExpand" WidthRequest="80" HorizontalOptions="FillAndExpand">
<WebView.Source WebView.EnableZoomControls="true" WebView.ScalesPageToFit = "true">
<HtmlWebViewSource x:Name="HighChart"/>
</WebView.Source>
</WebView>
</ScrollView>
</ContentPage>
This is my WebView

Answer 1

For Android specific (Within Shared project [FORMS])
XAML SOLUTION:
<ContentPage ...
xmlns:android="clr-namespace:Xamarin.Forms.PlatformConfiguration.AndroidSpecific;assembly=Xamarin.Forms.Core">
<WebView Source="https://www.xamarin.com"
android:WebView.EnableZoomControls="true"
android:WebView.DisplayZoomControls="true" />
C# SOLUTION:
using Xamarin.Forms.PlatformConfiguration;
using Xamarin.Forms.PlatformConfiguration.AndroidSpecific;
...
WebView.On<Android>().EnableZoomControls(true);
WebView.On<Android>().DisplayZoomControls(true);

Answer 2

I test on Android on iOS , it seems the problem only occurs on Android .
You could create a custom renderer to implement the zoom function, it works fine on my side .
[assembly: ExportRenderer(typeof(WebView), typeof(CustomWebViewRenderer))]
namespace PDFPOC.Droid
{
public class CustomWebViewRenderer : WebViewRenderer
{
public CustomWebViewRenderer(Context context) : base(context)
{
}
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
if (e.NewElement != null)
{
Control.Settings.AllowUniversalAccessFromFileURLs = true;
Control.Settings.SetSupportZoom(true);
Control.Settings.BuiltInZoomControls = true;
Control.Settings.DisplayZoomControls = true;
}
}
}
}