I'm writing Webview renderer in Xamarin for Windows Desktop project by following guide in Xamarin HybridWebView
[assembly: ExportRenderer(typeof(Xamarin.Forms.WebView), typeof(ProApp.Windows.Helpers.CustomWebViewRenderer))]
namespace ProApp.Windows.Helpers
{
public class CustomWebViewRenderer : ViewRenderer<Xamarin.Forms.WebView, global::Windows.UI.Xaml.Controls.WebView>
{
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.WebView> e)
{ //Debug Point
base.OnElementChanged(e);
if (this.Control == null)
{
}
}
}
}
I've similarly defined WebView Renderer in Android also. I'm running a Xamarin.Form Content page with WebView. The android WebView renderer is getting executed/debug but I'm not getting any debugger for Windows and code in Xamarin.Forms is running.
I also tried to add var t = new Windows.Helpers.CustomWebViewRenderer(); in App.xaml.cs to avoid any non-inclusion after build (to have some reference to class), but didn't work. Is there anything I'm missing?
The easier way to do it is to let the XF framework implement its webview code. Inherit from WebViewRenderer instead.
[assembly: ExportRenderer(typeof(WebView), typeof(CustomWebViewRenderer))]
namespace Mobile.WinRT.Renderers
{
public class CustomWebViewRenderer: WebViewRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<WebView> e)
{
base.OnElementChanged(e);
if (Control != null)
{
}
}
}
}
Also I recommend just creating a simple control in your XF project called something like CustomWebView that just inherits from WebView. Then you can render for this instead of every possible WebView in the app.
Related
I am having a Xamarin.Forms Prism application. It is using a WKWebView in ios Project to display a web page. In that page, other than the permission from the iOS, a permission popup from browser is also being displayed. Can anybody please help me with this? This is happening only in iOS.
https://learn.microsoft.com/en-us/answers/questions/1167987/how-to-fix-double-permission-popup-in-xamarin-ios
This thread helped me to solve this problem. Implement a class which is inherited from WKUIDelegate.
public class CustomWebViewDelegate : WKUIDelegate
{
[Export("webView:decideMediaCapturePermissionsForOrigin:initiatedByFrame:type:decisionHandler:")]
public override void RequestMediaCapturePermission(WKWebView webView, WKSecurityOrigin origin, WKFrameInfo frame, WKMediaCaptureType type, Action decisionHandler)
{
try
{
decisionHandler(WKPermissionDecision.Grant);
base.RequestMediaCapturePermission(webView, origin, frame, type, decisionHandler);
}
catch (Exception e)
{ }
}
}
Add this statement in the Renderer class.
webView.UIDelegate = new CustomWebViewDelegate();
I'm working on Embedded Images Tint color in xamarin forms using with this nuget package, working fine in android but not in iOS.
As per my search I used rendering mode to AlwaysTemplate but in my scenario I'm unable to use rendering mode.
what I'm doing is using the image references from solution file not from iOS assets.
Below is my code snippet.
<controls:TintedImage
x:Name="ColorChange"
Aspect="AspectFit"
HeightRequest="17"
Source="{local:ImageResource AppName.Images.dot.png}"
TintColor="{StaticResource PlaceholderColor}"
VerticalOptions="Center"
WidthRequest="17" />
I want to change TintColor if an image without rendering image for iOS in xamarin forms.
You can write a custom renderer of Image to change the tint color and UIImageRenderingMode.
In Xamarin.forms:
public class myImage : Image
{
}
In iOS project:
[assembly: ExportRenderer(typeof(myImage), typeof(myImageRenderer))]
namespace WorkingWithImages.iOS
{
public class myImageRenderer : ImageRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
{
base.OnElementChanged(e);
Control.TintColor = UIColor.Red;
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (Control.Image != null)
{
UIImage image = Control.Image;
image = image.ImageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate);
Control.Image = image;
}
}
}
}
How to get notified when Xamarin Native Android app goes to sleep or is terminated?
When searching, I only found an answer for Xamarin.Forms where the Application object allows to override OnSleep.
The background of this question is that I want to save settings when the app either goes to background or is terminated.
Just like the OnSleep method of Xamarin Forms the OnPause method is called in Android Native when the app goes into the background.
You can override OnPause in both an Activity and a Fragment something like this:
protected override void OnPause()
{
base.OnPause();
// Add your code here
}
Update
You can do the same on application level by adding the Android Application class :
Add a new C# class file in your project called MainApplication.cs.
Then add the Application.IActivityLifecycleCallbacks interface where you can find the activity paused method with the activity context in which it was paused so you can add it and do the needful.
#if DEBUG
[Application(Debuggable = true)]
#else
[Application(Debuggable = false)]
#endif
public class MainApplication : Application , Application.IActivityLifecycleCallbacks
{
public MainApplication(IntPtr handle, JniHandleOwnership transer)
: base(handle, transer)
{
}
public void OnActivityPaused(Android.App.Activity activity)
{
base.OnCreate();
// Add some code
}
public override void OnTerminate()
{
base.OnTerminate();
UnregisterActivityLifecycleCallbacks(this);
}
public override void OnCreate()
{
base.OnCreate();
RegisterActivityLifecycleCallbacks(this);
}
}
My project is built with master-detail navigation.
There are totally three pages in the list named as Resources, Contacts, and Login.
Everything works fine in iOS, but when the user presses the Droid/WinPhone devices hardware back button, the app should exit.
Is there any app-exit mechanism for Xamarin Forms which will work on all the devices.? (I mean native code not platform dependent)
Thanks in advance.
I did that on this way
In xamarin forms I added interface
public interface INativeHelper
{
void CloseApp();
}
In android project I made implementation of INativeHelper
public class NativeHelper : INativeHelper
{
public void CloseApp()
{
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
}
}
Implementation of INativeHelper in IOS
public class NativeHelper : INativeHelper
{
public void CloseApp()
{
Process.GetCurrentProcess().CloseMainWindow();
Process.GetCurrentProcess().Close();
}
}
And then just override method OnBackButtonPressed in page in Xamarin.Forms project
protected override bool OnBackButtonPressed()
{
INativeHelper nativeHelper = null;
nativeHelper = DependencyService.Get<INativeHelper>();
if (nativeHelper != null)
{
nativeHelper.CloseApp();
}
return base.OnBackButtonPressed();
}
I didn't made implementation for WinPhone, but it should be similar.
You can use a DepedencyService for closing an app when your physical back button is pressed:
In your UI (PCL), do the following:
protected override bool OnBackButtonPressed()
{
if (Device.OS == TargetPlatform.Android)
DependencyService.Get<IAndroidMethods>().CloseApp();
return base.OnBackButtonPressed();
}
Now implement the Android-specific logic in your Android project:
[assembly: Xamarin.Forms.Dependency(typeof(AndroidMethods))]
namespace Your.Namespace
{
public class AndroidMethods : IAndroidMethods
{
public void CloseApp()
{
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
}
}
}
Also create an Interface (in your UI PCL):
public interface IAndroidMethods
{
void CloseApp();
}
As far as I know there is no native way to exit the app in Xamarin application.
The only way is to use dependency service. Override OnBackButtonPressed function in your ContentPage and check it is the last page:
protected override bool OnBackButtonPressed()
{
if(navigation.NavigationStack.Count == 1)//navigation is MainPage.Navigation
DependencyService.Get<YourDependencyInterface>().CloseApp();
}
For Android in YourAndroidDependency class:
public void CloseApp()
{
(Xamarin.Forms.Forms.Context as Activity).Finish();
}
As for WinPhone I'm not sure but I believe it can be done in same way - dependency service.
Having experimented with all the above, I found that none of the above worked on a Google Pixel 3a, with latest version of Android
The command that came closest was
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
However it left the remains of the app still visible in the background.
The following worked for me when called from the Android Main Activity
public void ExitApp()
{
this.FinishAndRemoveTask();
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
}
The first line FinishAndRemoveTask removes the app from both the foreground and the background, however the Application process is still active, hence the need for the second command.
This is the more easy way found:
public void QuitApp(object sender, EventArgs args)
{
Process.GetCurrentProcess().CloseMainWindow();
Process.GetCurrentProcess().Close();
}
PS: Tested in android
You can use Environment.Exit(0);
I want to use Webview in Xamarin gtk Form. The problem is that i can't find Webview in toolbox.
Looking at this example i added some code in default MainWindow.cs code.
using System;
using Gtk;
using Xamarin.Forms;
public partial class MainWindow: Gtk.Window
{
public MainWindow () : base (Gtk.WindowType.Toplevel)
{
Build ();
WebView webView = new WebView
{
Source = new UrlWebViewSource
{
Url = "http://blog.xamarin.com/",
},
VerticalOptions = LayoutOptions.FillAndExpand
};
vbox2.Add (webView); //giving error since it webview is not widget.
}
protected void OnDeleteEvent (object sender, DeleteEventArgs a)
{
Gtk.Application.Quit ();
a.RetVal = true;
}
}
I am new to Xamarin and i don't know i can i create a xamarin gtk# tool that can run on OSX and windows.
I also want to fill htmlDocument and invoke click. Is it possible with xamarin gtk# webview