如何通过Xamarin.Forms提供iOS本地通知？

Question

I'm new in in mobile development and Xamarin. I'm trying to provide cross-platform local notifications via DependencyService.

I'm using Xamarin's tutorials for specific-platform(for iOS in this example):

https://developer.xamarin.com/guides/cross-platform/application_fundamentals/notifications/ios/local_notifications_in_ios_walkthrough/

So the problem is that when i press the button nothing happens. My code:

ContentPage :

using System;
using Xamarin.Forms;

namespace Tasker
{
    public class TestPage : ContentPage
    {
        StackLayout layout = new StackLayout();
        public TestPage ()
        {
            var notifyButton = new Button
            {
                Text = "Notethat",
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.CenterAndExpand,
            };
            layout.Children.Add (notifyButton);

            notifyButton.Clicked += (sender, e) => {
                DependencyService.Get<INotification>().CreateNotification();
            };
            this.Content = layout;
        }

    }
}

Then I've created interface for my cross-platform injection:

using System;
using Xamarin.Forms;

namespace Tasker
{
        public interface INotification
        {
            void  CreateNotification();
        }

}

OK. Then I implement my Notification interface for iOS:

using System;
using Xamarin.Forms;
using Tasker.iOS;
using UIKit;
using Foundation;
[assembly: Dependency(typeof(INotification_IOS))]
namespace Tasker.iOS
{
    public class INotification_IOS:INotification
    {
        public INotification_IOS ()
        {
        }
    public void  CreateNotification()
        {
            // create the notification
            var notification = new UILocalNotification();

            // set the fire date (the date time in which it will fire)
            notification.FireDate = NSDate.FromTimeIntervalSinceNow(1);

            // configure the alert
            notification.AlertAction = "Some info";
            notification.AlertBody = "Your one minute alert has fired!";

            //notification.

            // modify the badge
            notification.ApplicationIconBadgeNumber = 1;

            // set the sound to be the default sound
            notification.SoundName = UILocalNotification.DefaultSoundName;

            // schedule it
            UIApplication.SharedApplication.ScheduleLocalNotification(notification);

        }
    }
}

Then my AppDelegate class. I think that problem is somewhere here:

using Foundation;
using UIKit;
using Xamarin.Forms;

namespace Tasker.iOS
{
    [Register("AppDelegate")]
    public class AppDelegate :global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
    {
        private UIViewController viewController;
        private UIWindow window;
        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            global::Xamarin.Forms.Forms.Init ();//you can't remove it

            viewController = new UIViewController();
            window = new UIWindow ();


            window.RootViewController = viewController;
            window.MakeKeyAndVisible();


             //check for a notification
            if (options != null)
            {
                // check for a local notification
                if (options.ContainsKey(UIApplication.LaunchOptionsLocalNotificationKey))
                {
                    var localNotification = options[UIApplication.LaunchOptionsLocalNotificationKey] as UILocalNotification;
                    if (localNotification != null)
                    {
                        UIAlertController okayAlertController = UIAlertController.Create (localNotification.AlertAction, localNotification.AlertBody, UIAlertControllerStyle.Alert);
                        okayAlertController.AddAction (UIAlertAction.Create ("OK", UIAlertActionStyle.Default, null));
                        viewController.PresentViewController (okayAlertController, true, null);

                        // reset our badge
                        UIApplication.SharedApplication.ApplicationIconBadgeNumber = 0;
                    }
                }
            }

            if (UIDevice.CurrentDevice.CheckSystemVersion (8, 0)) {
                var notificationSettings = UIUserNotificationSettings.GetSettingsForTypes (
                    UIUserNotificationType.Alert | UIUserNotificationType.Badge | UIUserNotificationType.Sound, null
                );

                app.RegisterUserNotificationSettings (notificationSettings);
            } 
            LoadApplication (new App ());//if you will remove it, app won't be launched
            return base.FinishedLaunching (app, options);
            //return true;
        }

        public override void ReceivedLocalNotification(UIApplication application, UILocalNotification notification)
        {
            // show an alert
            UIAlertController okayAlertController = UIAlertController.Create (notification.AlertAction, notification.AlertBody, UIAlertControllerStyle.Alert);
            okayAlertController.AddAction (UIAlertAction.Create ("OK", UIAlertActionStyle.Default, null));
            viewController.PresentViewController (okayAlertController, true, null);

            // reset our badge
            UIApplication.SharedApplication.ApplicationIconBadgeNumber = 0;
        }
    }
}

So as you see i tried to make cross-platform local notification.

Exactly cross-platform function "CreateNotification()" works - I checked.

So the problem is somewhere where I create Alert or window for notification.

Will be grateful for any help!

Answer 1

You could try this plugin that is PCL

https://www.nuget.org/packages/Xam.Plugins.Notifier/