Xamarin Forms: Custom webview is not working in IOS - xamarin.forms

I am using Custom Webview for solving ITMS-90809: Deprecated API Usage - Apple will stop accepting submissions of apps that use UIWebView APIs. and parsing HTML data.
My Code:
MyWebView.cs
using Xamarin.Forms;
namespace CustomWebview
{
public class MyWebView : WebView
{
public static readonly BindableProperty UrlProperty = BindableProperty.Create(
propertyName: "Url",
returnType: typeof(string),
declaringType: typeof(MyWebView),
defaultValue: default(string));
public string Url
{
get { return (string)GetValue(UrlProperty); }
set { SetValue(UrlProperty, value); }
}
}
}
IOS
using CustomWebview;
using CustomWebview.iOS;
using WebKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
[assembly: ExportRenderer(typeof(MyWebView), typeof(MyWebViewRenderer))]
namespace CustomWebview.iOS
{
public class MyWebViewRenderer : ViewRenderer<MyWebView, WKWebView>
{
WKWebView _wkWebView;
protected override void OnElementChanged(ElementChangedEventArgs<MyWebView> e)
{
base.OnElementChanged(e);
if (Control == null)
{
var config = new WKWebViewConfiguration();
_wkWebView = new WKWebView(Frame, config);
SetNativeControl(_wkWebView);
}
if (e.NewElement != null)
{
Control.LoadHtmlString(Element.Url, null); //use this code instead
//Control.LoadRequest(new NSUrlRequest(new NSUrl(Element.Url)));
}
}
}
}
When I open the page having MyWebView the page redirects to Main.cs and shows the below exception.
I have uploaded a sample project here.

I found consumed a .Net Framework library in Forms project, please remove it and use .Net Standard HttpClient.
Secondly, try to disable the ATS for your certain URL like:
<key>NSAppTransportSecurity</key>
<dict>
<key>NSExceptionDomains</key>
<dict>
<key>services.catholicbrain.com</key>
<dict>
<key>NSIncludesSubdomains</key>
<true/>
<key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
<true/>
<key>NSTemporaryExceptionMinimumTLSVersion</key>
<string>TLSv1.1</string>
</dict>
</dict>
</dict>
Finally, move the loading URL code to OnElementPropertyChanged.
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == "Url")
{
Control.LoadHtmlString(Element.Url, null);
}
}
This answer is from another XF thread of mine.

Related

Set focus on Entry field in Xamarin.Forms MVVM (Prism)

I'm using Xamarin.Forms and Prism to create my mobile app.
I have a screen with 2 entries. When entering the screen, I'd like to set the focus on the first entry.
Then after the user entered data in this entry and validated it, I'd like to set the focus to the second entry.
Based on first answer:
I should do something wrong. I've created a small new Prism project to test it :
MainPage.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:testEntry"
x:Class="testEntry.Views.MainPage"
Title="{Binding Title}">
<StackLayout HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand">
<Label Text="Welcome to Xamarin Forms and Prism!" />
<local:MyEntry Placeholder="" x:Name="entry1" />
<Button Text="set focus on entry1" Clicked="Button_Clicked"/>
</StackLayout>
</ContentPage>
MainPage.xaml.cs
using Xamarin.Forms;
namespace testEntry.Views
{
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
}
protected override void OnAppearing()
{
base.OnAppearing();
entry1.Focus(); //Not Working
}
private void Button_Clicked(object sender, EventArgs e)
{
entry1.Focus(); //Working
}
}
}
MyEntry.cs (in Main project)
using Xamarin.Forms;
namespace testEntry
{
public class MyEntry : Entry
{
}
}
MyEntryRenderer.cs (in Android Project)
using Android.Content;
using Android.Views;
using Android.Views.Accessibility;
using Xamarin.Forms.Platform.Android;
namespace testEntry.Droid
{
public class MyEntryRenderer : EntryRenderer
{
public MyEntryRenderer(Context context) : base(context)
{
}
public static void Focus(View view)
{
view.SendAccessibilityEvent(EventTypes.ViewFocused);
}
}
}
Unfortunately, still nofocus on my field :'(
Finally, and thanks to Saamer, I found another way of doing it by using EventAggregator.
public class FocusChanged : PubSubEvent<String> { }
Then in my view model :
IEventAggregator _ea;
public MainPageViewModel(INavigationService navigationService, IEventAggregator eventAggregator) : base(navigationService)
{
_ea = eventAggregator;
}
In the viewModel, whenever I want to set the focus to a field, I'm sending an event :
_ea.GetEvent<FocusChanged>().Publish("Source");
And in my view's code behind, I handle this event:
IEventAggregator _ea;
public MainPage(IEventAggregator eventAggregator)
{
InitializeComponent();
_ea = eventAggregator;
_ea.GetEvent<FocusChanged>().Subscribe(SetFocusOnControl); //Name of method which will handle this event
}
/// set the focus on entry based on parameter
/// each event value will set focus on a specific entry (example: source is linked to entry txtScanSrc)
private async void SetFocusOnControl(String fieldName)
{
Entry l_view;
switch(fieldName)
{
case "source": l_view = this.FindByName<Entry>("txtScanSrc"); break;
case "quantity": l_view = this.FindByName<Entry>("txtQty"); break;
case "tote": l_view = this.FindByName<Entry>("txtScanTote"); break;
case "pallet": l_view = this.FindByName<Entry>("txtScanPalout"); break;
case "destination": l_view = this.FindByName<Entry>("txtScanDest"); break;
default: l_view = this.FindByName<Entry>("txtScanSrc"); break;
}
await WaitAndExecute(500, () => { l_view.Focus(); });
}
There's a way of doing this using the Accessibility APIs of each of the platforms. Xamarin forms doesn't have all the platform features of accessibility yet so you d have to create a custom renderer and then call the focus method in a life cycle event of the page.
So calling this Focus function would cause the app to focus on that element. You generally don't want to do it because the app purposefully focuses on what it does so accessible users have a consistent experience. But if you really want to override the default behavior, in Android it's something like this
public static void Focus(View view)
{
view.SendAccessibilityEvent(EventTypes.ViewFocused);
}
And in iOS, you have to use the PostNotification apis which will be some variation of this
UIAccessibility.PostNotification(UIAccessibilityPostNotification.ScreenChanged, entry element)
You can look more into Accessibility Focus to get the exact answer

Owin SuppressDefaultHostAuthentication and existing HTTP Module

In an existing ASP.NET MVC application I've added WebAPI. I've used most of the template code that's generated from a brand new project.
I'm facing some issues concerning authentication. In order to avoid the normal login procedure for the api I've added:
config.SuppressDefaultHostAuthentication();
config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));
as per the default template.
However, I get an error calling my api stating: "No OWIN authentication manager is associated with the request."
I found out that this is caused because there's a custom HTTP module active. Removing the module from the web.config makes the API work. However the 'normal' web application needs this module.
Is there a way to let the HTTP module coexist with the owin authentication?
The Module is defined like this:
public class MGPContextInitializerModule : IHttpModule
{
public void Init(HttpApplication context)
{
if (context != null)
{
context.AcquireRequestState += AcquireRequestState;
context.BeginRequest += new EventHandler(BeginRequest);
}
}
private void AcquireRequestState(object sender, EventArgs e)
{
if (HttpContext.Current.Session != null)
{
InitializeUserCulture(new HttpContextWrapper(HttpContext.Current).GetSessionID());
}
}
private void BeginRequest(object sender, EventArgs e)
{
InitializeCustomer((HttpApplication)sender);
}
private static void InitializeInstantie(HttpApplication application)
{
HttpContextBase contextBase = new HttpContextWrapper(application.Context);
RouteData routeData = RouteTable.Routes.GetRouteData(contextBase);
if (routeData != null)
{
var customer = routeData.Values["customer"];
if (customer != null)
{
Initializer.InitializeCustomer(customer.ToString());
}
}
}
}

Couldn't get Ninject-Interception via Attributes to work, what did I do wrong?

I'm trying build out our logging framework using EntLib Logging and use attribute to indicate which class/method should be logged. So I think Interception would be a good choice. I'm a super noob to Ninject and Interception and I's following the tutorial at Innovatian Software on how to use interception via attributes. But when I run the app, BeforeInvoke and AfterInvoke was never called. Help Please, Thank You!
using System;
using System.Diagnostics;
using System.Collections.Generic;
using Castle.Core;
using Ninject;
using Ninject.Extensions.Interception;
using Ninject.Extensions.Interception.Attributes;
using Ninject.Extensions.Interception.Request;
class Program
{
static void Main(string[] args)
{
var kernel = new StandardKernel();
kernel.Bind<ObjectWithMethodInterceptor>().ToSelf();
var test= kernel.Get<ObjectWithMethodInterceptor>();
test.Foo();
test.Bar();
Console.ReadLine();
}
}
public class TraceLogAttribute : InterceptAttribute
{
public override IInterceptor CreateInterceptor(IProxyRequest request)
{
return request.Context.Kernel.Get<TimingInterceptor>();
}
}
public class TimingInterceptor : SimpleInterceptor
{
readonly Stopwatch _stopwatch = new Stopwatch();
protected override void BeforeInvoke(IInvocation invocation)
{
Console.WriteLine("Before Invoke");
_stopwatch.Start();
}
protected override void AfterInvoke(IInvocation invocation)
{
Console.WriteLine("After Invoke");
_stopwatch.Stop();
string message = string.Format("Execution of {0} took {1}.",
invocation.Request.Method,
_stopwatch.Elapsed);
Console.WriteLine(message);
_stopwatch.Reset();
}
}
public class ObjectWithMethodInterceptor
{
[TraceLog] // intercepted
public virtual void Foo()
{
Console.WriteLine("Foo - User Code");
}
// not intercepted
public virtual void Bar()
{
Console.WriteLine("Bar - User Code");
}
}
I figured it out, I missed the part where I've to disable auto module loading and manually load the DynamicProxy2Module to the kernel. Here's the change to the code:
//var kernel = new StandardKernel(); //Automatic Module Loading doesn't work
var kernel = new StandardKernel(new NinjectSettings() { LoadExtensions = false }, new DynamicProxy2Module());
Hope this help someone else.

tool/script to visit all pages in an ASP.NET project?

Does anybody know of a tool, script, package, whatever that I can use to visit all pages in an ASP.NET Webforms web application project? (we aren't using any MVC functionality)
Preferably, I would like to be able to generate a list of URLs to hit, edit the list so I can add some query string params, hit all the pages in the list, and collect HTTP response codes: (200, 404, 500, 301, whatever).
Design time
Instead of using string literals for URLs in your application, define Url() methods in each page class like this:
public static string Url() { get { return "~/this_page.aspx"; } }
public static string Url(int ID) { get { return "~/this_page.aspx?id=" + ID; } }
Or list all URLs in a static class
public static class URL {
public static string Login() { get { return "~/login.aspx"; } }
public static string DisplayRecord(int recordID)
{ get { return "~/display.aspx?id=" + recordID; } }
Runtime
Use a web testing framework to crawl all links and edit the result. I blogged about one possible solution using Selenium.
I made a WinForms application that gets the pages that can be accessed from the .csproject and can open them by clicking a button.
using System;
using System.Collections.Generic;
using System.IO;
using System.Windows.Forms;
using System.Xml;
using System.Xml.XPath;
namespace OpenAllPages
{
public partial class Form1 : Form
{
public static IList<string> Pages;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
string xmlstring = ReadXml("TaskManager.csproj");
Pages = ParseAllPages(xmlstring);
pagesListBox.DataSource = Pages;
}
private string ReadXml(string location)
{
try
{
var myFile = new StreamReader(location);
string myString = myFile.ReadToEnd();
myFile.Close();
return myString;
}
catch (Exception e)
{
MessageBox.Show(String.Format("An error occurred: '{0}'", e.Message));
}
return null;
}
private IList<string> ParseAllPages(string xmlstring)
{
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlstring);
XPathNavigator nav = xmlDoc.DocumentElement.CreateNavigator();
XmlNamespaceManager manager = new XmlNamespaceManager(nav.NameTable);
manager.AddNamespace("x", "http://schemas.microsoft.com/developer/msbuild/2003");
var elements = nav.Select("x:ItemGroup/x:Content", manager);
var pageList = new List<string>();
while (elements.MoveNext())
{
var page = elements.Current.GetAttribute("Include", "");
if (page.EndsWith(".aspx"))
pageList.Add(page);
}
return pageList as IList<string>;
}
private string AddPagePrefix(string page)
{
return "http://localhost:8080/" + page;
}
private void openAllButton_Click(object sender, EventArgs e)
{
foreach (string page in Pages)
System.Diagnostics.Process.Start("chrome.exe", AddPagePrefix(page));
}
}
}
Here is a link to the code
You need to place the project file which contains the pages you want to open in the OpenAllPages project and set it's Copy to Output property to "Copy if newer".
I Form1_Load change TaskManager.csproj to the name of your project file.
And in:
System.Diagnostics.Process.Start("chrome.exe", AddPagePrefix(page));
rename parameter to the executable of the browser you are using.

How to use Castle Windsor with ASP.Net web forms?

I am trying to wire up dependency injection with Windsor to standard asp.net web forms. I think I have achieved this using a HttpModule and a CustomAttribute (code shown below), although the solution seems a little clunky and was wondering if there is a better supported solution out of the box with Windsor?
There are several files all shown together here
// index.aspx.cs
public partial class IndexPage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Logger.Write("page loading");
}
[Inject]
public ILogger Logger { get; set; }
}
// WindsorHttpModule.cs
public class WindsorHttpModule : IHttpModule
{
private HttpApplication _application;
private IoCProvider _iocProvider;
public void Init(HttpApplication context)
{
_application = context;
_iocProvider = context as IoCProvider;
if(_iocProvider == null)
{
throw new InvalidOperationException("Application must implement IoCProvider");
}
_application.PreRequestHandlerExecute += InitiateWindsor;
}
private void InitiateWindsor(object sender, System.EventArgs e)
{
Page currentPage = _application.Context.CurrentHandler as Page;
if(currentPage != null)
{
InjectPropertiesOn(currentPage);
currentPage.InitComplete += delegate { InjectUserControls(currentPage); };
}
}
private void InjectUserControls(Control parent)
{
if(parent.Controls != null)
{
foreach (Control control in parent.Controls)
{
if(control is UserControl)
{
InjectPropertiesOn(control);
}
InjectUserControls(control);
}
}
}
private void InjectPropertiesOn(object currentPage)
{
PropertyInfo[] properties = currentPage.GetType().GetProperties();
foreach(PropertyInfo property in properties)
{
object[] attributes = property.GetCustomAttributes(typeof (InjectAttribute), false);
if(attributes != null && attributes.Length > 0)
{
object valueToInject = _iocProvider.Container.Resolve(property.PropertyType);
property.SetValue(currentPage, valueToInject, null);
}
}
}
}
// Global.asax.cs
public class Global : System.Web.HttpApplication, IoCProvider
{
private IWindsorContainer _container;
public override void Init()
{
base.Init();
InitializeIoC();
}
private void InitializeIoC()
{
_container = new WindsorContainer();
_container.AddComponent<ILogger, Logger>();
}
public IWindsorContainer Container
{
get { return _container; }
}
}
public interface IoCProvider
{
IWindsorContainer Container { get; }
}
I think you're basically on the right track - If you have not already I would suggest taking a look at Rhino Igloo, an WebForms MVC framework, Here's a good blog post on this and the source is here - Ayende (the Author of Rhino Igloo) tackles the issue of using Windsor with webforms quite well in this project/library.
I would cache the reflection info if you're going to inject the entire nested set of controls, that could end up being a bit of a performance hog I suspect.
Last of all spring.net approaches this in a more configuration-oriented way, but it might be worth taking a look at their implementation - here's a good reference blog post on this.
Here's a modified version of the OP's code that (i) caches injected properties to avoid repeated reflection calls, (ii) releases all resolved components, (iii) encapsulates container access so as not to expose implementation.
// global.asax.cs
public class Global : HttpApplication
{
private static IWindsorContainer _container;
protected void Application_Start(object sender, EventArgs e)
{
_container = new WindsorContainer();
_container.Install(FromAssembly.This());
}
internal static object Resolve(Type type)
{
return _container.Resolve(type);
}
internal static void Release(object component)
{
_container.Release(component);
}
//...
}
// WindsorHttpModule.cs
public class WindsorHttpModule : IHttpModule
{
// cache the properties to inject for each page
private static readonly ConcurrentDictionary<Type, PropertyInfo[]> InjectedProperties = new ConcurrentDictionary<Type, PropertyInfo[]>();
private HttpApplication _context;
public void Init(HttpApplication context)
{
_context = context;
_context.PreRequestHandlerExecute += InjectProperties;
_context.EndRequest += ReleaseComponents;
}
private void InjectProperties(object sender, EventArgs e)
{
var currentPage = _context.Context.CurrentHandler as Page;
if (currentPage != null)
{
InjectProperties(currentPage);
currentPage.InitComplete += delegate { InjectUserControls(currentPage); };
}
}
private void InjectUserControls(Control parent)
{
foreach (Control control in parent.Controls)
{
if (control is UserControl)
{
InjectProperties(control);
}
InjectUserControls(control);
}
}
private void InjectProperties(Control control)
{
ResolvedComponents = new List<object>();
var pageType = control.GetType();
PropertyInfo[] properties;
if (!InjectedProperties.TryGetValue(pageType, out properties))
{
properties = control.GetType().GetProperties()
.Where(p => p.GetCustomAttributes(typeof(InjectAttribute), false).Length > 0)
.ToArray();
InjectedProperties.TryAdd(pageType, properties);
}
foreach (var property in properties)
{
var component = Global.Resolve(property.PropertyType);
property.SetValue(control, component, null);
ResolvedComponents.Add(component);
}
}
private void ReleaseComponents(object sender, EventArgs e)
{
var resolvedComponents = ResolvedComponents;
if (resolvedComponents != null)
{
foreach (var component in ResolvedComponents)
{
Global.Release(component);
}
}
}
private List<object> ResolvedComponents
{
get { return (List<object>)HttpContext.Current.Items["ResolvedComponents"]; }
set { HttpContext.Current.Items["ResolvedComponents"] = value; }
}
public void Dispose()
{ }
}
I've recently started at a company where there are a lot of legacy webform apps, so this looks to be a real interesting approach, and could offer a way forward if we wanted to add DI to existing web pages, thanks.
One point I noticed is that the Injection method uses the container.Resolve to explicitly resolve components, therefore I think we may need to do a container.Release on the components when the Page Unloads.
If we have transient components and don't do this then we may face memory leakages. Not sure how components with Per Web Request lifestyles would behave (i.e. would Windsor pick them up at the end of the web request, even though we explicitly resolved them) but here too may want to play safe.
Therefore the module may need to be extended to keep track of the components that it resolves and release them so that Windsor knows when to clean up.
One thing that was missing from the accepted answers was the fact that the http module needs to be registered in the web.config file (depending on the application) before the module will actually resolve the dependencies on the code-behind pages. What you need is :
<system.webServer>
<modules>
<add name="ClassNameForHttpModuleHere" type="NamespaceForClass"/>
</modules>
</system.webServer>
Other than that the accepted solutions worked like a charm.
Reference to the Microsoft website for adding http modules: https://msdn.microsoft.com/en-us/library/ms227673.aspx
Rather than doing it like this, you could also use a type resolver directly with something like:
ILogger Logger = ResolveType.Of<ILogger>();

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