显示提示知道位置

Question

我使用Xamarin WebView控制器来显示一个网站(在iOS/Android中).网站的主页提示访问设备位置.但是,当我在WebView(来自应用程序)上拥有此网站时,该提示未显示.当我在浏览器上打开此站点时,它会从同一个移动设备显示消息框.我只是想知道是否有可能在Xamarin WebView上有这样的提示？

这是一个示例提示.

这就是我在Xamarin应用程序中的全部内容.

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:nCollar"
             x:Class="nCollar.MainPage">
    <ContentPage.Padding>
        <OnPlatform x:TypeArguments="Thickness">
            <OnPlatform.iOS>0,20,0,0</OnPlatform.iOS>
            <OnPlatform.Android>0,0,0,0</OnPlatform.Android>
            <OnPlatform.WinPhone>0,0,0,0</OnPlatform.WinPhone>
        </OnPlatform>
    </ContentPage.Padding>

    <WebView x:Name="webView"
                 Grid.Row="0"
                 VerticalOptions="FillAndExpand" 
                 Source="https://www.ncollar.com.au/"/>

</ContentPage>

更新1

Android的

我已经尝试过这篇文章中提到的解决方案,但它仍然没有显示提示.

WebViewRenderer.cs

using Android.Webkit;
using Xamarin.Forms.Platform.Android;

[assembly: Xamarin.Forms.ExportRenderer(typeof(TestApp.Controls.WebView), typeof(TestApp.Droid.Renderers.WebViewRenderer))]
namespace TestApp.Droid.Renderers
{
    public class WebViewRenderer : Xamarin.Forms.Platform.Android.WebViewRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.WebView> e)
        {
            base.OnElementChanged(e);

            if (this.Control == null)
            {
                return;
            }

            var webView = this.Element as TestApp.Controls.WebView;
            if (webView == null)
            {
                return;
            }


           // webView. ings.JavaScriptEnabled = true;
            this.Control.Settings.DomStorageEnabled = true;
            this.Control.Settings.DisplayZoomControls = true;
            this.Control.Settings.BuiltInZoomControls = true;
            this.Control.Settings.SetGeolocationEnabled(true);
            this.Control.Settings.JavaScriptCanOpenWindowsAutomatically = true;

            this.Control.SetWebViewClient(new GeoWebViewClient());
            this.Control.SetWebChromeClient(new GeoWebChromeClient());
        }
    }

    public class GeoWebChromeClient : WebChromeClient
    {
        public override void OnGeolocationPermissionsShowPrompt(string origin, GeolocationPermissions.ICallback callback)
        {
            callback.Invoke(origin, true, false);
        }
    }

    public class GeoWebViewClient : WebViewClient
    {
        public override bool ShouldOverrideUrlLoading(WebView view, string url)
        {
            view.LoadUrl(url);
            return true;
        }
    }
}

表现

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-sdk android:minSdkVersion="15" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <application android:label="TestApp.Android"></application>
</manifest>

iOS版

尝试NSLocationWhenInUseUsageDescription在plist文件中,但没有区别.

Answer 1

更新答案（带代码）

对于 Android - 您将需要一个用于 WebView 控件的自定义渲染器。（参考：要点）

public class ExtendedWebViewRenderer : WebViewRenderer
{
    protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.WebView> e)
    {
        base.OnElementChanged(e);

        if (e.OldElement != null || Element == null)
        {
            return;
        }

        Control.Settings.JavaScriptEnabled = true;
        Control.Settings.SetGeolocationEnabled(true);
        Control.Settings.SetGeolocationDatabasePath(Control.Context.FilesDir.Path);

        Control.SetWebViewClient(new CustomWebViewClient());
        Control.SetWebChromeClient(new CustomChromeClient(Control.Context));
    }
}

public class CustomWebViewClient : WebViewClient
{
    public override bool ShouldOverrideUrlLoading(Android.Webkit.WebView view, string url)
    {
        view.LoadUrl(url);
        return true;
    }
}

public class CustomChromeClient : WebChromeClient
{
    private readonly Context _context;

    public CustomChromeClient(Context context)
    {
        _context = context;
    }

    public override void OnGeolocationPermissionsShowPrompt(string origin, GeolocationPermissions.ICallback callback)
    {
        const bool remember = false;
        var builder = new AlertDialog.Builder(_context);
        builder.SetTitle("Location")
            .SetMessage(string.Format("{0} would like to use your current location", origin))
            .SetPositiveButton("Allow", (sender, args) => callback.Invoke(origin, true, remember))
            .SetNegativeButton("Disallow", (sender, args) => callback.Invoke(origin, false, remember));
        var alert = builder.Create();
        alert.Show();
    }
}

清单权限

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />

使用示例

<StackLayout Margin="30" BackgroundColor="#ededed">
    <Label Text="WebView location prompt sample" Margin="15" HorizontalOptions="Center" />
    <local:ExtendedWebView x:Name="webView" Source="https://www.yellowpages.com/" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" />
</StackLayout>

并且，如果是 iOS，您需要在文件NSLocationWhenInUseUsageDescription中设置描述info.plist。

并显示提示。

完整的代码示例可以在此链接中找到

原答案

对于 Android - 您应该能够通过为 WebView 添加特定于平台的渲染器来解决此问题，并通过添加自定义 WebChromeClient 来实现权限处理。

如果是 iOS - 您需要在信息 plist 中添加NSLocationWhenInUseUsageDescription 描述