本文介绍了Xamarin.Forms ShouldOverrideUrlLoading 触发器的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想在 JavascriptWebViewClient.cs 中使用 ShouldOverrideUrlLoading 触发 mainpage.xaml 中的活动指示器.
I want to trigger the activityindicator in mainpage.xaml using ShouldOverrideUrlLoading inside JavascriptWebViewClient.cs.
MyJavascriptWebViewClient.cs:
MyJavascriptWebViewClient.cs:
public class JavascriptWebViewClient : WebViewClient
{
readonly string _javascript;
public JavascriptWebViewClient(string javascript)
{
_javascript = javascript;
}
[Obsolete]
public override bool ShouldOverrideUrlLoading(WebView view, string url)
{
view.LoadUrl(url);
Toast.MakeText(Android.App.Application.Context, "Loading...", ToastLength.Long).Show();
Console.WriteLine("Page Changing Now..");
return true;
}
public override void OnPageStarted(WebView view, string url, Android.Graphics.Bitmap favicon)
{
// DependencyService.Get<ILoadingIndicator>().Show();
base.OnPageStarted(view, url, favicon);
Console.WriteLine("Sayfa Doluyor.");
}
public override void OnPageFinished(WebView view, string url)
{
base.OnPageFinished(view, url);
view.EvaluateJavascript(_javascript, null);
Console.WriteLine("Sayfa Doldu");
}
}
Mainpage.xaml 代码:
Mainpage.xaml code:
<ContentPage
x:Class="XFHybridWebViewAdvDemo.MainPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:controls="clr-namespace:XFHybridWebViewAdvDemo.Controls;assembly=XFHybridWebViewAdvDemo"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:iOsSpecific="clr-namespace:Xamarin.Forms.PlatformConfiguration.iOSSpecific;assembly=Xamarin.Forms.Core"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
iOsSpecific:Page.UseSafeArea="true"
mc:Ignorable="d">
<ContentPage.Content>
<!-- Place new controls here -->
<AbsoluteLayout>
<StackLayout AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0,0,1,1">
<controls:HybridWebView
x:Name="webViewElement"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand"
Navigating="Browser_Navigating"
Navigated="Browser_Navigated"/>
</StackLayout>
<StackLayout BackgroundColor="Aqua" AbsoluteLayout.LayoutFlags="PositionProportional" AbsoluteLayout.LayoutBounds="0.5,0.5,AutoSize,AutoSize">
<Label Text="Başlangıç"/>
<Label Text="Bitiş"/>
</StackLayout>
<ActivityIndicator x:Name="loading" IsRunning="False" IsVisible="false"/>
</AbsoluteLayout>
</ContentPage.Content>
Mainpage.xaml.cs 代码:
Mainpage.xaml.cs code:
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class MainPage : ContentPage
{
private DeviceFeaturesHelper _deviceFeaturesHelper;
public MainPage()
{
InitializeComponent();
NavigationPage.SetHasNavigationBar(this, false);
webViewElement.Source = "https://mywebsite.com/";
webViewElement.RegisterAction(ExecuteActionFromJavascript);
_deviceFeaturesHelper = new DeviceFeaturesHelper();
}
protected override void OnAppearing()
{
base.OnAppearing();
//loading.IsVisible = true;
//loading.IsRunning = true;
//await DisplayAlert("Alert", "Uygulama açılıyor", "OK");
}
private void Browser_Navigating(object sender, WebNavigatingEventArgs args)
{
Console.WriteLine("geçiyor");
//loading.IsVisible = true;
//loading.IsRunning = true;
}
private void Browser_Navigated(object sender, WebNavigatedEventArgs args)
{
//loading.IsVisible = false;
//loading.IsRunning = false;
Console.WriteLine("geçti");
}
protected override bool OnBackButtonPressed()
{
webViewElement.GoBack();
return true;
}
//sayfadaki sonuc id'si icindeki veriyi alır
private async Task<string> tokenal()
{
var firebaseCek = DependencyService.Get<IFireBaseTokenService>();
return await webViewElement.EvaluateJavaScriptAsync($"document.getElementById('token_alan').value= '{firebaseCek.GetDeviceModel()}';");
}
private async Task<string> deviceal()
{
var deviceName = DeviceInfo.Name;
var platform = DeviceInfo.Platform;
var device = DeviceInfo.Model;
return await webViewElement.EvaluateJavaScriptAsync($"document.getElementById('device_alan').value= '{deviceName} - {device} - {platform}';");
}
private async Task<string> GetMail()
{
return await webViewElement.EvaluateJavaScriptAsync("document.getElementById('ozel_email').innerHTML");
}
private async Task<string> GetKullaniciAdi()
{
return await webViewElement.EvaluateJavaScriptAsync("document.getElementById('ozel_kullanici_adi').innerHTML");
}
private async Task<string> GetAdi()
{
return await webViewElement.EvaluateJavaScriptAsync("document.getElementById('ozel_adi').innerHTML");
}
private async Task<string> GetSoyadi()
{
return await webViewElement.EvaluateJavaScriptAsync("document.getElementById('ozel_soyadi').innerHTML");
}
private async Task<string> GetGorunenAdi()
{
return await webViewElement.EvaluateJavaScriptAsync("document.getElementById('gorunen_ad').innerHTML");
}
[Obsolete]
private async void ExecuteActionFromJavascript(string param1, string param2)
{
if (param1 != null && param1.Equals("PHOTO") && param2.Equals("CAMERA"))
{
var result = await _deviceFeaturesHelper.TakePhoto(this);
if (result != null)
{
await webViewElement.EvaluateJavaScriptAsync($"setresult_takephoto('{result}')");
}
}
HybridWebViewRenderer.cs
HybridWebViewRenderer.cs
[assembly: ExportRenderer(typeof(HybridWebView), typeof(HybridWebViewRenderer))]
命名空间 XFHybridWebViewAdvDemo.Droid.Renderers{公共类 HybridWebViewRenderer : WebViewRenderer{private const string JavascriptFunction = "function invokeXamarinFormsAction(data){jsBridge.invokeAction(data);}";上下文_context;
namespace XFHybridWebViewAdvDemo.Droid.Renderers{public class HybridWebViewRenderer : WebViewRenderer{private const string JavascriptFunction = "function invokeXamarinFormsAction(data){jsBridge.invokeAction(data);}";Context _context;
public HybridWebViewRenderer(Context context) : base(context)
{
_context = context;
}
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
Control.Settings.JavaScriptEnabled = true;
Control.Settings.SetAppCacheEnabled(true);
Control.Settings.CacheMode = Android.Webkit.CacheModes.Normal;
Control.Settings.SetRenderPriority(RenderPriority.High);
Control.Settings.DomStorageEnabled = true;
Control.Settings.LoadsImagesAutomatically = true;
//Control.Settings.BlockNetworkImage = true;
if (e.OldElement != null)
{
Control.RemoveJavascriptInterface("jsBridge");
((HybridWebView)Element).Cleanup();
}
if (e.NewElement != null)
{
Control.SetWebViewClient(new JavascriptWebViewClient($"javascript: {JavascriptFunction}"));
Control.AddJavascriptInterface(new JsBridge(this), "jsBridge");
//// No need this since we're loading dynamically generated HTML content
//Control.LoadUrl($@"file:///android_asset/Content/{((HybridWebView)Element).Uri}");
}
}
}
}
HybridWebView.cs
HybridWebView.cs
public class HybridWebView : WebView
{
private Action<string, string> _action;
public void RegisterAction(Action<string, string> callback)
{
_action = callback;
}
public void Cleanup()
{
_action = null;
}
public void InvokeAction(string param1, string param2)
{
if (_action == null || (param1 == null && param2 == null))
{
return;
}
if (MainThread.IsMainThread)
_action.Invoke(param1, param2);
else
MainThread.BeginInvokeOnMainThread(() => _action.Invoke(param1, param2));
}
}
推荐答案
由于 ShouldOverrideUrlLoading 方法已过时，我强烈建议您使用另一种方法，例如 OnPageStarted , OnPageFinished ,OnReceivedError .
Since ShouldOverrideUrlLoading method is obsolete , I strongly recommend you to use another method like OnPageStarted , OnPageFinished ,OnReceivedError .
在OnPageStarted方法中显示activityindicator，在OnPageFinished和OnReceivedError方法中隐藏它.
Show the activityindicator in OnPageStarted method , and hide it in OnPageFinished and OnReceivedError method .
为了实现它，我们可以在这里使用消息中心.
To achieve it we can use Messaging Center here .
public override void OnPageStarted(Android.Webkit.WebView view, string url, Bitmap favicon)
{
base.OnPageStarted(view, url, favicon);
MessagingCenter.Send<object, bool>(this, "Hi", true);
}
public override void OnPageFinished(Android.Webkit.WebView view, string url)
{
base.OnPageFinished(view, url);
view.EvaluateJavascript(_javascript, null);
MessagingCenter.Send<object,bool>(this, "Hi",false);
}
public override void OnReceivedError(Android.Webkit.WebView view, IWebResourceRequest request, WebResourceError error)
{
base.OnReceivedError(view, request, error);
MessagingCenter.Send<object, bool>(this, "Hi", false);
}
主页
MessagingCenter.Subscribe<object, bool>(this,"Hi",(obj,show)=> {
loading.IsVisible = show;
loading.IsRunning = show;
});
这篇关于Xamarin.Forms ShouldOverrideUrlLoading 触发器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！