I want to call Content page class from Android .cs Class.
I use StartActivity(new Intent(Application.Context, typeof(LoginPage)));
showing error message
"System.ArgumentException: type Parameter name: Type is not derived
from a java type "
Does anyone know the solution for this? Please help me in Xamarin.Forms.
This should be you App.xaml.cs class
public App()
{
MainPage = new NavigationPage ( new MainPage());
}
MainActivity.cs file
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
{
private TextView setting;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
LoadApplication(new App());
SetContentView(Resource.Layout.HomeScreen);
setting = FindViewById<TextView>(Resource.Id.settingText);
//check setting button is null or have value
setting.Click += delegate
{
Xamarin.Forms.Application.Current.MainPage.Navigation.PushAsync(new LoginPage());
};
}
}
Use code above & debug to check if setting button have instance or is null.
Replace typeof(LoginPage) with LoginPage.Class or LoginPage::Class.java (kotlin)
Related
I am using Xamarin (C#) code for a macOS app. I have created the WKWebView and have outlet, added Navigation and UI delegates and trying to open an URL.
The Navigation delegates methods are getting called, but not sure what am I missing that UI Delegates method is not getting called.
Any help / guidance what to look for, or what mistake I am doing here, please.
Here's the code and image of same:
public override void ViewDidLoad()
{
base.ViewDidLoad();
var url = new NSUrl("https://google.com");
var request = new NSMutableUrlRequest(url);
_webView.UIDelegate = new WebViewDelegate();
_webView.NavigationDelegate = new WebViewNavigationDelegate();
_webView.LoadRequest(request);
}
}
internal class WebViewDelegate : WKUIDelegate
{
public override WKWebView CreateWebView(WKWebView webView, WKWebViewConfiguration configuration, WKNavigationAction navigationAction, WKWindowFeatures windowFeatures)
{
Console.WriteLine("this doesn't reach");
return null;
}
}
internal class WebViewNavigationDelegate : WKNavigationDelegate
{
public override void DidFinishNavigation(WKWebView webView, WKNavigation navigation)
{
Console.WriteLine("this prints");
}
}
I wan't to share a link via social media from custom renderer
public class CustomActions : ICustomActions
{
Context context = Android.App.Application.Context;
public void ShareThisLink()
{
Intent sharingInt = new Intent(Android.Content.Intent.ActionSend);
sharingInt.SetType("text/plain");
string shareBody = "https://www.google.com";
sharingInt.PutExtra(Android.Content.Intent.ExtraSubject, "Subject");
sharingInt.PutExtra(Android.Content.Intent.ExtraText, shareBody);
context.StartActivity(Intent.CreateChooser(sharingInt, "Share via"));
}
}
This error occur
Android.Util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
even when I added the below code I still get same error
sharingInt.AddFlags(ActivityFlags.NewTask);
The problem is that Intent.CreateChooser creates yet another Intent. What you want to do is to set the flag on this new intent:
public void ShareThisLink()
{
Intent sharingInt = new Intent(Android.Content.Intent.ActionSend);
sharingInt.SetType("text/plain");
string shareBody = "https://www.google.com";
sharingInt.PutExtra(Android.Content.Intent.ExtraSubject, "Subject");
sharingInt.PutExtra(Android.Content.Intent.ExtraText, shareBody);
var intent = Intent.CreateChooser(sharingInt, "Share via");
intent.AddFlags(ActivityFlags.NewTask);
context.StartActivity(intent);
}
Alternatively to avoid the need to do this, you could cache the MainActivity instance Xamarin.Forms uses:
public MainActivity
{
public static MainActivity Instance {get;private set;}
protected override void OnCreate(Bundle bundle)
{
Instance = this;
...
}
}
And then use the Instance as the Context in your code instead of the Application.Context
I'm working out of the Xamarin Forms for MVVMCross 5 Solution Template and updated the packages to the latest version (5.3.2 for MVVMCross). Doing that changes some namespaces around particularly in the UWP project.
It seems that I need to resolve IMvxViewPresenter as MvxFormsUwpViewPresenter which takes a IMvxWindowsFrame as an argument. In the setup file method of Setup.cs there's a XamlControls.Frame rootFrame passed as an argument but I'm not sure if that's suppose to be cast somehow as IMvxWindowsFrame.
Where can you pull the object that implements IMvxWindowsFrame from or is there another way to turn the rootFrame into an IMvxWindowsFrame legitimately.
public class Setup : MvxFormsWindowsSetup
{
private readonly LaunchActivatedEventArgs _launchActivatedEventArgs;
public Setup(XamlControls.Frame rootFrame, LaunchActivatedEventArgs e) : base(rootFrame, e)
{
_launchActivatedEventArgs = e;
// Mvx.RegisterSingleton<IMvxWindowsFrame>(rootFrame);
}
protected override void InitializeFirstChance()
{
base.InitializeFirstChance();
Mvx.RegisterSingleton<Core.Services.ILocalizeService>(new Services.LocalizeService());
Mvx.RegisterSingleton<ISettings>(CrossSettings.Current);
Mvx.RegisterType<IMvxViewPresenter, MvxFormsUwpViewPresenter>();
}
protected override MvxFormsApplication CreateFormsApplication()
{
return new Core.FormsApp();
}
protected override IMvxApplication CreateApp()
{
return new Core.MvxApp();
}
protected override IMvxTrace CreateDebugTrace()
{
return new Core.DebugTrace();
}
}
public sealed partial class MainPage : WindowsPage
{
public MainPage()
{
this.InitializeComponent();
var start = Mvx.Resolve<IMvxAppStart>();
start.Start();
var presenter = Mvx.Resolve<IMvxViewPresenter>() as MvxFormsUwpViewPresenter;
LoadApplication(presenter.FormsApplication);
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
}
}
EDIT: I've been looking more into the class MvxFormsWindowsSetup in the source code at https://github.com/MvvmCross/MvvmCross/blob/develop/MvvmCross-Forms/MvvmCross.Forms.Uwp/Platform/MvxFormsWindowsSetup.cs. It appears that in the method CreateViewPresenter that the IMvxViewPresenter is registered as a singleton with the MvxWrappedFrame already inside but by default the code does not resolve when calling var presenter = Mvx.Resolve() as MvxFormsUwpViewPresenter; in the windows page. Possible bug? Trying to see if I can resolve it myself.
Looks like it fails to resolve even if I put the code right after when Mvx is suppose to register the type / singleton
protected override IMvxWindowsViewPresenter CreateViewPresenter(IMvxWindowsFrame rootFrame)
{
var presenter = new MvxFormsUwpViewPresenter(rootFrame, FormsApplication);
Mvx.RegisterSingleton<IMvxFormsViewPresenter>(presenter);
var presenter2 = Mvx.GetSingleton<IMvxViewPresenter>() as MvxFormsUwpViewPresenter;
return presenter;
}
When updating to MvvmCross 5.3.2 for UWP, the presenter needs to resolve as IMvxFormsViewPresenter rather than IMvxViewPresenter. Change the interface type and it should load properly.
public MainPage()
{
this.InitializeComponent();
var start = Mvx.Resolve<IMvxAppStart>();
start.Start();
var presenter = Mvx.Resolve<IMvxFormsViewPresenter>() as MvxFormsUwpViewPresenter;
LoadApplication(presenter.FormsApplication);
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
}
I want to use several Android activities. First is general application. Second is notification view. They have different activity settings and therefore I can't use one activity for this issue.
I try to do this:
[Activity(Label = "Life Manager", MainLauncher = true, Icon = "#drawable/icon")]
public class MainActivity : FormsApplicationActivity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
Forms.Init(this, bundle);
ActionBar.SetIcon(new ColorDrawable(Color.Transparent));
LoadApplication(new TimeManagerApplication());
Device.StartTimer(new TimeSpan(0, 0, 0, 5), OpenNotificationActivity);
}
private bool OpenNotificationActivity()
{
Intent intent = new Intent(this, typeof(NotificationActivity));
StartActivity(intent);
return false;
}
}
[Activity(Label = "NotificationActivity")]
public class NotificationActivity : FormsApplicationActivity
{
protected override void OnCreate(Bundle savedInstanceState)
{
RequestWindowFeature(WindowFeatures.NoTitle);
Window.AddFlags(WindowManagerFlags.Fullscreen | WindowManagerFlags.KeepScreenOn);
base.OnCreate(savedInstanceState);
Forms.Init(this, savedInstanceState);
LoadApplication(new NotificiationApplication());
}
}
In this line:
LoadApplication(new NotificiationApplication());
I take an error:
System.NullReferenceException: Object reference not set to an instance of an object.
How can I use two android activities in one application and use cross-platform Xamarin.Forms views for it?
Update:
Without these lines application perfectly works:
//RequestWindowFeature(WindowFeatures.NoTitle);
//Window.AddFlags(WindowManagerFlags.Fullscreen | WindowManagerFlags.KeepScreenOn);
But how can I hide status bar and use fullscreen view?
I decided this issue.
To take Fullscreen view without status bar is enough use only Window Flags
Window.AddFlags(WindowManagerFlags.Fullscreen | WindowManagerFlags.KeepScreenOn);
without:
RequestWindowFeature(WindowFeatures.NoTitle);
Application works as expected without exceptions.
How can I enable large heap in my Xamarin.Forms application ?
Here is MainActivity.cs Android code:
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
global::Xamarin.Forms.Forms.Init(this, bundle);
RoundedBoxViewRenderer.Init();
LoadApplication(new App());
}
}
See Exception Screenshot below:
Go to project Options > Android Build > General > Enable MultiDex & Options > Android Build > Advacnced > JavaHeapSize (Set 3G) , In manifest file you can add android:largeHeap="true" in Application Tag
<application android:largeHeap="true"/>
The Xamarin way of setting the Dalvik/Art large heap via the Appication attribute:
Application.cs
using System;
using Android.App;
using Android.Runtime;
namespace LargeHeap
{
[Application(LargeHeap = true)]
public class XamarinApplication : Application
{
public XamarinApplication(IntPtr handle, JniHandleOwnership ownerShip) : base(handle, ownerShip)
{
}
}
}
If true, then the process should be created with a large Dalvik heap; otherwise, the process will be created with the default Dalvik heap.
Ref: https://developer.xamarin.com/api/property/Android.App.ApplicationAttribute.LargeHeap/
My contribution, it worked for me:
[assembly: Application(LargeHeap = true)]
namespace Project.Droid
{
[Activity(.............)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
}
}