<zxing:ZXingScannerView IsScanning="True" OnScanResult="OnScanResult"/>
i have this on the xaml file, but i want to use mvvm so i have the onscanresult eventhandler in the viewmodel. How can i use that instead of the one in the code behind?
public void OnScanResult(ZXing.Result result)
{
Device.BeginInvokeOnMainThread(() =>
{
ScanResult = result.Text + " (type: " + result.BarcodeFormat + ")";
});
}
Just create a new version of ContentPage that creates an event to command if you don't want to use a behaviour:
public class ZxingContentPage : ZXingScannerPage
{
public static readonly BindableProperty ScanResultCommandProperty =
BindableProperty.Create(
nameof(ScanResultCommand),
typeof(ICommand),
typeof(ZxingContentPage),
default(ICommand)
);
public ICommand ScanResultCommand
{
get { return (ICommand)GetValue(ScanResultCommandProperty); }
set { SetValue(ScanResultCommandProperty, value); }
}
public ZxingContentPage(MobileBarcodeScanningOptions options) : base(options)
{
OnScanResult += ZxingContentPage_OnScanResult;
}
private void ZxingContentPage_OnScanResult(ZXing.Result result)
{
if (ScanResultCommand?.CanExecute(result) == true)
{
ScanResultCommand.Execute(result);
}
}
}
And then use it like below:
<?xml version="1.0" encoding="utf-8" ?>
<views:ZxingContentPage
x:Class="NameSpace.Zxing.ZxingMobileScannerView"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:views="clr-namespace:QRST.Views.Generic"
IsScanning="True"
ScanResultCommand="{Binding ZxingScanResultCommand}" />
Good luck
Feel free to get back in case of queries.
Related
I created demo application with Xamarin.Forms (5.X.X)
And i created share extension. Everything is good until here.
I want to get image from share extension but i cant get.
I tried almost everything.
public class CustomShareViewController: SLComposeServiceViewController
{
public CustomShareViewController(IntPtr handle) : base(handle)
{
}
public override void DidReceiveMemoryWarning()
{
// Releases the view if it doesn't have a superview.
base.DidReceiveMemoryWarning();
// Release any cached data, images, etc that aren't in use.
}
public override async void ViewDidLoad()
{
base.ViewDidLoad();
string urlstr = string.Empty;
NSExtensionItem item = ExtensionContext.InputItems[0];
var itemProvider = item.Attachments[0];
var type = itemProvider.Description.Split('"');
if (itemProvider.HasItemConformingTo(type[1]))
{
var load = await itemProvider.LoadItemAsync(type[1], null);
NSUrl newUrl = (NSUrl)load;
urlstr = newUrl.FilePathUrl.ToString();
}
if (!Xamarin.Forms.Forms.IsInitialized)
Xamarin.Forms.Forms.Init();
// Create an instance of XF page with associated View Model
var xfPage = new ShareMainPage();
var viewModel = (ShareMainPageViewModel)xfPage.BindingContext;
viewModel.Message = urlstr;
viewModel.Image = urlstr;
//viewModel.BindableImage = ImageSource.FromStream(() => new MemoryStream(byteArray));
// Override the behavior to complete the execution of the Extension when a user press the button
viewModel.DoCommand = new Command(() => DoneClicked());
// Convert XF page to a native UIViewController which can be consumed by the iOS Extension
var newController = xfPage.CreateViewController();
// Make sure the presentation style is set to full screen to avoid rendering the original entry point
newController.ModalPresentationStyle = UIModalPresentationStyle.FormSheet;
// Present new view controller as a regular view controller
this.PresentModalViewController(newController, false);
//var someController = this.Storyboard.InstantiateViewController("SomeController") as SomeViewController;
//NavigationController.PushViewController(someController, true);
//var itemProvider = inputItem?.Attachments?[0] as NSItemProvider;
//if (itemProvider.HasItemConformingTo("public.url"))
//{
// itemProvider.LoadPreviewImage(null, (item, error) => {
// if (item is UIImage)
// {
// var image = item as UIImage;
// var data = image.AsPNG();
// ImageView.Image = UIImage.LoadFromData(data);
// }
// });
//}
}
public override bool ShouldInteractWithUrl(UITextView textView, NSUrl url, NSRange characterRange, UITextItemInteraction interaction)
{
return base.ShouldInteractWithUrl(textView, url, characterRange, interaction);
}
public override bool IsContentValid()
{
// Do validation of contentText and/or NSExtensionContext attachments here
return true;
}
public override void DidSelectPost()
{
// This is called after the user selects Post. Do the upload of contentText and/or NSExtensionContext attachments.
// Inform the host that we're done, so it un-blocks its UI. Note: Alternatively you could call super's -didSelectPost, which will similarly complete the extension context.
}
public override void PresentationAnimationDidFinish()
{
base.PresentationAnimationDidFinish();
}
private void DoneClicked()
{
// Return any edited content to the host app.
// This template doesn't do anything, so we just echo the passed-in items.
ExtensionContext.CompleteRequest(ExtensionContext.InputItems, null);
}
private void WriteToDebugFile(string dbgText)
{
var documents = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
var filename = Path.Combine(documents, "Share-Extension-Debug.txt");
if (!File.Exists(filename))
{
File.WriteAllText(filename, $"\n{DateTime.Now} - {dbgText}");
}
else
{
File.AppendAllText(filename, $"\n{DateTime.Now} - {dbgText}");
}
}
}
I tried two ways.
Bind file path and get from there. ImageResource.FromFile(...) but it doesnt work.
Bind stream and it doesnt work too.
My sharepage.xml is
<?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:Demo.ViewModels"
x:DataType="local:ShareMainPageViewModel"
xmlns:converters="clr-namespace:LifeApp.Mobile.Converters"
BackgroundColor="Green"
x:Class="LifeApp.Mobile.Views.ShareMainPage">
<ContentPage.BindingContext>
<local:ShareMainPageViewModel Message="Hello from Xamarin.Forms!" />
</ContentPage.BindingContext>
<ContentPage.Content>
<StackLayout HorizontalOptions="Center" VerticalOptions="Center">
<Image Source="{Binding BindableImage}"
VerticalOptions="Start"
HorizontalOptions="CenterAndExpand" WidthRequest="200" HeightRequest="150"/>
<Label Text="{Binding Message}" TextColor="Black" FontSize="Medium" VerticalTextAlignment="Center"/>
<Button Command="{Binding DoCommand}" Text="Do the jungle!" TextColor="Black" />
</StackLayout>
</ContentPage.Content>
And SharePageViewModel
using System;
using System.ComponentModel;
using System.IO;
using System.Windows.Input;
using Xamarin.Essentials;
using Xamarin.Forms;
using Xamarin.Forms.Shapes;
namespace Demo.ViewModels
{
public class ShareMainPageViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private string _message;
public string Message
{
get { return _message; }
set
{
if (_message != value)
{
_message = value;
PropertyChanged?.Invoke(this, new
PropertyChangedEventArgs(nameof(Message)));
}
}
}
private string _image;
public string Image
{
get { return _image; }
set
{
if (_image != value)
{
_image = value;
PropertyChanged?.Invoke(this, new
PropertyChangedEventArgs(nameof(Image)));
}
}
}
public ImageSource _bindableImage { get; set; }
public ImageSource BindableImage
{
get
{
return _bindableImage;
}
set
{
if (_bindableImage !=null)
{
_bindableImage = value;
PropertyChanged?.Invoke(this, new
PropertyChangedEventArgs(nameof(BindableImage)));
}
}
}
private ICommand _doCommand;
public ICommand DoCommand
{
get { return _doCommand; }
set
{
if (_doCommand != value)
{
_doCommand = value;
PropertyChanged?.Invoke(this, new
PropertyChangedEventArgs(nameof(DoCommand)));
}
}
}
public ShareMainPageViewModel()
{
DoCommand = new Command(OnDoCommandExecuted);
}
private void OnDoCommandExecuted(object state)
{
// Acr.UserDialogs.UserDialogs.Instance.Alert("Completed");
Message = $"Job {Environment.TickCount} has been completed!";
}
}
}
I can get image file path but i cant bind and show image
file:///Users/xxxx/Library/Developer/CoreSimulator/Devices/58453DF3-58CF-4591-AC91-6A096FD7B814/data/Containers/Data/Application/1466F475-0F58-4F94-8511-B0BD9FE86DCA/tmp/WKFileShare-FbFp8eSD/adcf0796-2088-4d85-9420-c1d58c15cca4/....JPG
How can i solve this problem.
We customize the toolbar menu for navigation back button in xamarin forms ios. I am getting below crash in appcenter.
ToolbarMenuCustomRenderer.ViewWillAppear (System.Boolean animated)
SIGABRT: Object reference not set to an instance of an object
Code snippet below:
public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
CustomToolbarContentPage page = Element as CustomToolbarContentPage;
if (page == null)
return;
#region for soft back button
UIViewController root = NavigationController.TopViewController;
if (!page.NeedOverrideSoftBackButton)
return;
string title = "<" + (string.IsNullOrEmpty(NavigationPage.GetBackButtonTitle(Element)) ? "" : NavigationPage.GetBackButtonTitle(Element));
root.NavigationItem.SetLeftBarButtonItem(
new UIBarButtonItem(title, UIBarButtonItemStyle.Plain, (sender, args) =>
{
page.OnSoftBackButtonPressed();
}), true);
#endregion
}
How to resolve this in xamarin forms ios?
I create a sample app with your code and works fine, you can check the code below to see if you miss something:
NewPage:
namespace My_Forms_test.Views
{
public partial class NewPage2 : ContentPage
{
public NewPage2()
{
InitializeComponent();
}
public void OnSoftBackButtonPressed()
{
Navigation.PopToRootAsync();
}
}
}
CustomRenderer:
[assembly:ExportRenderer(typeof(NewPage2),typeof(MyPageRenderer))]
namespace My_Forms_test.iOS
{
public class MyPageRenderer:PageRenderer
{
public MyPageRenderer()
{
}
public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
NewPage2 page=Element as NewPage2;
UIViewController root = NavigationController.TopViewController;
string title = "<" + (string.IsNullOrEmpty(NavigationPage.GetBackButtonTitle(Element)) ? " " : NavigationPage.GetBackButtonTitle(Element));
root.NavigationItem.SetLeftBarButtonItem(
new UIBarButtonItem(title, UIBarButtonItemStyle.Plain, (sender, args) =>
{
page.OnSoftBackButtonPressed();
Console.WriteLine("This method is trigged"); }), true);
}
}
Here are ScreenShots:
You can also refer to this documents https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/custom-renderer/contentpage
This seems like a simple thing - I want to use a WebView to load / run some JavaScript from a 3rd party.
When I load the page I get a message saying "You must allow popups for this to work". I think I need to create a custom WebView (for iOS and Android!?) and I assume I need one in the shared project too?
I added this to my Android project:
using Android.Content;
using MyApp.Custom;
using MyApp.Droid.Custom;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
[assembly: ExportRenderer(typeof(CustomWebView), typeof(CustomWebViewRenderer))]
namespace MyApp.Droid.Custom
{
public class CustomWebViewRenderer : WebViewRenderer
{
public CustomWebViewRenderer(Context context) : base(context)
{
}
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
Control.Settings.JavaScriptCanOpenWindowsAutomatically = true;
Control.Settings.JavaScriptEnabled = true;
}
}
}
and this to my shared project
using Xamarin.Forms;
namespace MyKRing.Custom
{
public class CustomWebView : WebView
{
}
}
and then used "CustomWebView" in my XAML.
<custom:CustomWebView x:Name="WebView"
HeightRequest="1000"
Source="{Binding WebViewContent}"
WidthRequest="1000" />
My TestPageViewModel has
public WebViewSource WebViewContent
{
get => _webViewContent;
set => SetProperty(ref _webViewContent, value);
}
public TestPageViewModel()
{
AmountEntryFrameVisible = true;
NuapayFrameVisible = false;
ConfirmLoadCommand = new Command(ExecuteConfirmLoadCommand);
var localHtml = new HtmlWebViewSource();
localHtml.Html = #"<html>
<body>
<p>This is a test</p>
<script src='https://testurl.com/test.js\'></script>
<script>
TestJS.showUI('1234567890', 'https://testurl.com/ui/');
</script>
</body>
</html>";
WebViewContent = localHtml;
}
With the aim of making the JS run when the page is loaded by WebView.
Am I anywhere close? What is wrong with the above, as it just doesn't do anything (that ( can see).
1. Create the CustomWebView and create the ShowDialog method.
public class CustomWebView : WebView
{
Action<string> action;
public static readonly BindableProperty UriProperty = BindableProperty.Create(
propertyName: "Uri",
returnType: typeof(string),
declaringType: typeof(CustomWebView ),
defaultValue: default(string));
public string Uri
{
get { return (string)GetValue(UriProperty); }
set { SetValue(UriProperty, value); }
}
public void RegisterAction(Action<string> callback)
{
action = callback;
}
public void Cleanup()
{
action = null;
}
public void ShowDialog(string data)
{
if (action == null || data == null)
{
return;
}
action.Invoke(data);
}
}
2. Consume the CustomWebView
<local:CustomWebView x:Name="customWebView " Uri="index.html" />
3. Register the ShowDiaplg action to be invoked from JavaScript
customWebView.RegisterAction(data => DisplayAlert("Alert", DateTime.Now + "/n" + data, "OK"));
4. Create the custom renderer on Android platform.
CustomWebViewRenderer .cs:
[assembly: ExportRenderer(typeof(CustomWebView ), typeof(CustomWebViewRenderer))]
namespace CustomRenderer.Droid
{
public class CustomWebViewRenderer: WebViewRenderer
{
const string JavascriptFunction = "function invokeCSharpAction(data){jsBridge2.showDialog(data);}";
Context _context;
public CustomWebViewRenderer (Context context) : base(context)
{
_context = context;
}
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
if (e.OldElement != null)
{
Control.RemoveJavascriptInterface("jsBridge");
((CustomWebView )Element).Cleanup();
}
if (e.NewElement != null)
{
Control.SetWebViewClient(new JavascriptWebViewClient2(this, $"javascript: {JavascriptFunction}"));
Control.AddJavascriptInterface(new JSBridge2(this), "jsBridge2");
Control.LoadUrl($"file:///android_asset/Content/{((CustomWebView )Element).Uri}");
}
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
((CustomWebView )Element).Cleanup();
}
base.Dispose(disposing);
}
}
}
JavascriptWebViewClient2.cs:
public class JavascriptWebViewClient2 : FormsWebViewClient
{
string _javascript;
public JavascriptWebViewClient2(CustomWebViewRenderer renderer, string javascript) : base(renderer)
{
_javascript = javascript;
}
public override void OnPageFinished(WebView view, string url)
{
base.OnPageFinished(view, url);
view.EvaluateJavascript(_javascript, null);
}
}
JSBridge2.cs:
public class JSBridge2 : Java.Lang.Object
{
readonly WeakReference<CustomWebViewRenderer > hybridWebViewRenderer;
public JSBridge2(CustomWebViewRenderer hybridRenderer)
{
hybridWebViewRenderer = new WeakReference<CustomWebViewRenderer >(hybridRenderer);
}
[JavascriptInterface]
[Export("showDialog")]
public void ShowDialog(string data)
{
CustomWebViewRenderer hybridRenderer;
if (hybridWebViewRenderer != null && hybridWebViewRenderer.TryGetTarget(out hybridRenderer))
{
((CustomWebView)hybridRenderer.Element).ShowDialog(data);
}
//string ret = "Alert :" + DateTime.Now;
//return ret;
}
}
I followed the code sample in the link below. https://learn.microsoft.com/en-us/samples/xamarin/xamarin-forms-samples/customrenderers-hybridwebview/
I'm following tutorials/examples for a Xamarin Forms project, where there is a view with a C# code-behind, binding to a view model. However, I want to catch an exception occurring in the view model and display it in an alert or use any other common technique for displaying errors.
Here is the view, which reloads data using a refresh:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="MyCompany.App.Views.DashboardPage"
xmlns:vm="clr-namespace:MyCompany.App.ViewModels"
xmlns:dashboard="clr-namespace:MyCompany.App.ViewModels.Dashboard;assembly=MyCompany.App"
Title="{Binding Title}">
...
<RefreshView x:DataType="dashboard:DashboardViewModel" Command="{Binding LoadItemsCommand}" IsRefreshing="{Binding IsBusy, Mode=TwoWay}">
... content
</RefreshView>
</ContentPage>
Then I have the C# code behind for the XAML:
public partial class DashboardPage : ContentPage
{
DashboardViewModel _viewModel;
public DashboardPage()
{
InitializeComponent();
BindingContext = _viewModel = new DashboardViewModel();
}
protected override void OnAppearing()
{
base.OnAppearing();
_viewModel.OnAppearing();
}
}
And finally the view model where the loading happens. It inherits from the BaseViewModel which is provided in the tutorials.
public class DashboardViewModel : BaseViewModel
{
private DashboardItemViewModel _selectedItem;
public ObservableCollection<DashboardItemViewModel> Items { get; }
public Command LoadItemsCommand { get; }
public Command<DashboardItemViewModel> ItemTapped { get; }
public DashboardViewModel()
{
Title = "Dashboard";
Items = new ObservableCollection<DashboardItemViewModel>();
LoadItemsCommand = new Command(async () => await ExecuteLoadItemsCommand());
ItemTapped = new Command<DashboardItemViewModel>(OnItemSelected);
}
async Task ExecuteLoadItemsCommand()
{
IsBusy = true;
try
{
Items.Clear();
var items = await GetItems();
foreach (var item in items)
{
Items.Add(item);
}
}
finally
{
IsBusy = false;
}
}
private static async Task<List<DashboardItemViewModel>> GetItems()
{
// Where errors happen
return items;
}
public void OnAppearing()
{
IsBusy = true;
SelectedItem = null;
}
public DashboardItemViewModel SelectedItem
{
get => _selectedItem;
set
{
SetProperty(ref _selectedItem, value);
OnItemSelected(value);
}
}
async void OnItemSelected(DashboardItemViewModel item)
{
if (item == null || item.Uri.IsNotSet())
return;
await Shell.Current.GoToAsync(item.Uri);
}
}
I can't see any overridable methods in ContentPage for catching exceptions. What's the best way to catch an exception and display it in an alert?
I'm not sure what exactly you want, but for catching errors I use try/catch method.
try
{
//your code here
}
catch(Exception exc)
{
await App.Current.MainPage.DisplayAlert("Warning", "Error: " + exc, "Ok");
}
I am having an issue that relates to a post on GitHub. User nirbil summarizes it best:
If a website utilizes the historyApi then the WebView's CanGoBack CanGoForward are wrong.
Steps to reproduce -
Set the webview's source to a single page web application
Navigate within the application to a different url (should utilize
the pushstate)
Navigate back -> CanGoForward changes to true
Navigate within the application again by following some link ->
CanGoForward erroneously does not change to false
On windows this behavior can be traced to the webview's renderer - https://github.com/xamarin/Xamarin.Forms/blob/master/Xamarin.Forms.Platform.UAP/WebViewRenderer.cs
Here is the original post on GitHub https://github.com/xamarin/Xamarin.Forms/issues/7691
A lot of ideas are suggested on how to solve the problem however, my grasp of Xamarin Forms is somewhat lacking. Any ideas on how to solve the issue?
You could add the source of webview to use renderer. I use the code sample on GitHub. https://github.com/xamarin/Xamarin.Forms/issues/7691
The original:
Set the source of webview.
<WebView x:Name="webView" Source="https://www.google.com" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"></WebView>
Now:
This question on GitHub has been collected. You could follow it on GitHub. It would be fixed soon.
I solved it using a custom Xamarin Forms WebView with custom CanGoBack/Forward properties.
You can find the it here:
https://github.com/nirbil/XF.CanGoWebView
Following are the main bits of the solution.
CustomWebView control with new bindable properties:
public class CustomWebView : WebView
{
public CustomWebView() {}
public static BindableProperty CustomCanGoForwardProperty =
BindableProperty.Create(
nameof(CustomCanGoForward),
typeof(bool),
typeof(CustomWebView),
false,
BindingMode.OneWayToSource);
public static BindableProperty CustomCanGoBackProperty =
BindableProperty.Create(
nameof(CustomCanGoBack),
typeof(bool),
typeof(CustomWebView),
defaultValue: false,
BindingMode.OneWayToSource);
public bool CustomCanGoForward
{
get => (bool)GetValue(CustomCanGoForwardProperty);
set => SetValue(CustomCanGoForwardProperty, value);
}
public bool CustomCanGoBack
{
get => (bool)GetValue(CustomCanGoBackProperty);
set => SetValue(CustomCanGoBackProperty, value);
}
}
Custom WebViewRenderer on Android:
public class CustomWebViewRenderer : WebViewRenderer
{
protected override WebViewClient GetWebViewClient()
{
CustomWebViewClient webViewClient = new CustomWebViewClient(this);
webViewClient.AddressChanged += AddressChanged;
return webViewClient;
}
private void AddressChanged(string url)
{
if (Element is CustomWebView customWebView && Control != null)
{
customWebView.CustomCanGoBack = Control.CanGoBack();
customWebView.CustomCanGoForward = Control.CanGoForward();
}
}
}
Android CustomWebViewClient that intercepts changes and alerts the renderer:
public class CustomWebViewClient: FormsWebViewClient
{
public delegate void AddressChangedEventHandler(string url);
public event AddressChangedEventHandler AddressChanged;
public CustomWebViewClient(WebViewRenderer renderer) : base(renderer) {}
public override void DoUpdateVisitedHistory(WebView view, string url, bool isReload)
{
base.DoUpdateVisitedHistory(view, url, isReload);
AddressChanged?.Invoke(view.Url);
}
}
Custom WebViewRenderer on UWP:
public class CustomWebViewRenderer : WebViewRenderer
{
bool _registeredControl = false;
long _goBackRegistrationToken = 0;
long _goForwardRegistrationToken = 0;
protected override void Dispose(bool disposing)
{
UnregisterControl();
base.Dispose(disposing);
}
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
RegisterControl();
}
private void UnregisterControl()
{
if (Control != null && _registeredControl)
{
_registeredControl = false;
Control.UnregisterPropertyChangedCallback(Windows.UI.Xaml.Controls.WebView.CanGoBackProperty, _goBackRegistrationToken);
Control.UnregisterPropertyChangedCallback(Windows.UI.Xaml.Controls.WebView.CanGoForwardProperty, _goForwardRegistrationToken);
}
}
private void RegisterControl()
{
if (Control != null && !_registeredControl)
{
_registeredControl = true;
_goBackRegistrationToken = Control.RegisterPropertyChangedCallback(Windows.UI.Xaml.Controls.WebView.CanGoBackProperty, new Windows.UI.Xaml.DependencyPropertyChangedCallback(OnWebViewCanGoBackChanged));
_goForwardRegistrationToken = Control.RegisterPropertyChangedCallback(Windows.UI.Xaml.Controls.WebView.CanGoForwardProperty, new Windows.UI.Xaml.DependencyPropertyChangedCallback(OnWebViewCanGoForwardChanged));
}
}
private void OnWebViewCanGoBackChanged(Windows.UI.Xaml.DependencyObject sender, Windows.UI.Xaml.DependencyProperty dp)
{
((CustomWebView)Element).CustomCanGoBack = Control.CanGoBack;
}
private void OnWebViewCanGoForwardChanged(Windows.UI.Xaml.DependencyObject sender, Windows.UI.Xaml.DependencyProperty dp)
{
((CustomWebView)Element).CustomCanGoForward = Control.CanGoForward;
}
}