Xamarin IOS - 应用程序关闭时显示本地通知

Question

我有一个 Xamarin IOS 应用程序，它每 10 秒获取一次用户位置，即使该应用程序被终止也是如此。我使用这个库：“https://jamesmontemagno.github.io/GeolocatorPlugin/”.

我想要的是：当应用程序关闭或打开并且用户在特定位置时，我想显示本地通知。当应用程序关闭时，这甚至可能吗？我找不到这方面的信息，因为它总是关于远程通知。

Answer 1

应在应用程序启动后立即请求通知权限，方法是将以下代码添加到 AppDelegate 的 FinishedLaunching 方法并设置所需的通知类型 (UNAuthorizationOptions)：

...
using UserNotifications;
...



 public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
   {
       ....
           
        //after iOS 10
        if(UIDevice.CurrentDevice.CheckSystemVersion(10,0))
        {
            UNUserNotificationCenter center = UNUserNotificationCenter.Current;

            center.RequestAuthorization(UNAuthorizationOptions.Alert | UNAuthorizationOptions.Sound | UNAuthorizationOptions.UNAuthorizationOptions.Badge, (bool arg1, NSError arg2) =>
                 {

                 });

            center.Delegate = new NotificationDelegate();
        }

        else if(UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
        {

            var settings = UIUserNotificationSettings.GetSettingsForTypes(UIUserNotificationType.Alert| UIUserNotificationType.Badge| UIUserNotificationType.Sound,new NSSet());

            UIApplication.SharedApplication.RegisterUserNotificationSettings(settings);

        }

        return true;
    }

iOS10 的新增功能，当应用程序位于前台并触发通知时，它可以以不同方式处理通知。通过提供 UNUserNotificationCenterDelegate 并实现 UserNotificationCentermethod，应用程序可以接管显示通知的责任。例如：

using System;
using ObjCRuntime;
using UserNotifications;


namespace workplat
{
 public class NotificationDelegate:UNUserNotificationCenterDelegate
   {
    public NotificationDelegate()
    {
    }

    public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
    {
        // Do something with the notification
        Console.WriteLine("Active Notification: {0}", notification);

        // Tell system to display the notification anyway or use
        // `None` to say we have handled the display locally.
        completionHandler(UNNotificationPresentationOptions.Alert|UNNotificationPresentationOptions.Sound);
    }


    public override void DidReceiveNotificationResponse(UNUserNotificationCenter center, UNNotificationResponse response, Action completionHandler)
    {
        // Take action based on Action ID
        switch (response.ActionIdentifier)
        {
            case "reply":
                // Do something
                break;
            default:
                // Take action based on identifier
                if (response.IsDefaultAction)
                {
                    // Handle default action...
                }
                else if (response.IsDismissAction)
                {
                    // Handle dismiss action
                }
                break;
        }

        // Inform caller it has been handled
        completionHandler();
    }

  }
}

要创建自定义操作并向系统注册，请使用以下代码：

 public void RegisterNotification(long time)
    {
        UNUserNotificationCenter center = UNUserNotificationCenter.Current;

        //creat a UNMutableNotificationContent which contains your notification content
        UNMutableNotificationContent notificationContent = new UNMutableNotificationContent();

        notificationContent.Title = "xxx";
        notificationContent.Body= "xxxx";

        notificationContent.Sound = UNNotificationSound.Default;

        UNTimeIntervalNotificationTrigger trigger = UNTimeIntervalNotificationTrigger.CreateTrigger(time, false);

        UNNotificationRequest request = UNNotificationRequest.FromIdentifier("FiveSecond", notificationContent, trigger);


        center.AddNotificationRequest(request,(NSError obj) => 
        {
           


        });

    }

调用此方法时，例如：

RegisterNotification(20);//set the time you want to push notification

通知将在20秒后推送，enen如果您关闭您的应用程序。您可以在上传位置后放置此行。

我的demo已经上传到我的github，大家可以下载参考：Demo Link.

您可以访问 link 了解更多信息和详细信息：MicroSoft Document

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