Xamarin IOS - 应用程序关闭时显示本地通知

Posted 2023-02-23

【中文标题】Xamarin IOS - 应用程序关闭时显示本地通知

【英文标题】：Xamarin IOS - Show local notification when application is closed

【发布时间】：2020-07-23 07:49:25

【问题描述】：

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

我想要的是：当应用程序关闭或打开并且用户位于特定位置时，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。

【参考方案1】：

应在应用启动后立即通过将以下代码添加到AppDelegate 的FinishedLaunching 方法并设置所需的通知类型（UNAuthorizationOptions）来请求通知权限：

...
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;
    

iOS 10 的新增功能，当应用程序在前台并触发通知时，它可以以不同的方式处理通知。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();
    

  

要在系统中创建和注册自定义操作，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) => 
        
           


        );

    

当你调用这个方法时，例如：

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

通知将在 20 秒后推送，如果您关闭应用程序。您可以在上传位置后添加此行。

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

您可以访问链接以获取更多信息和详细信息：MicroSoft Document

【讨论】：

当应用关闭时，通知被标签时是否会触发 DidReceiveNotificationResponse？

是的，点击通知就会被调用