Xamarin.iOS 在应用未关闭时处理推送通知

Question

如果应用程序在后台，我设法使用didReceiveRemoteNotification 方法处理推送通知。如果应用程序处于前台且未关闭，是否有办法处理推送通知？谢谢

Answer 1

我通过下面显示的示例 app.delegte.cs 代码在 Xamarin iOS 中获得了前台和后台通知。

   using Foundation;
   using System;
   using System.Diagnostics;
   using System.Linq;
   using UIKit;
   using UserNotifications;
   using WindowsAzure.Messaging;
   using Firebase.Core;
   using Firebase.CloudMessaging;
   using System.Runtime.CompilerServices;
   using ObjCRuntime;

   namespace NotificationHubSample.iOS

{ [注册("AppDelegate")]

   public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
    private SBNotificationHub Hub { get; set; }
    

    public override bool FinishedLaunching(UIApplication app, NSDictionary options)
    {
        global::Xamarin.Forms.Forms.Init();
        LoadApplication(new App());

        

        base.FinishedLaunching(app, options);

        Firebase.Core.App.Configure();

        RegisterForRemoteNotifications();

        UIApplication.SharedApplication.SetMinimumBackgroundFetchInterval(UIApplication.BackgroundFetchIntervalMinimum);


        return true;
    }

    void RegisterForRemoteNotifications()
    {
        // register for remote notifications based on system version
        if (UIDevice.CurrentDevice.CheckSystemVersion(10, 0))
        {
            
            

            UNUserNotificationCenter.Current.RequestAuthorization(UNAuthorizationOptions.Alert |
                UNAuthorizationOptions.Sound |
                UNAuthorizationOptions.Sound,
                (granted, error) =>
                {
                    if (granted)
                        InvokeOnMainThread(UIApplication.SharedApplication.RegisterForRemoteNotifications);
                });
        }
        else if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
        {
            var pushSettings = UIUserNotificationSettings.GetSettingsForTypes(
            UIUserNotificationType.Alert | UIUserNotificationType.Badge | UIUserNotificationType.Sound,
            new NSSet());

            UIApplication.SharedApplication.RegisterUserNotificationSettings(pushSettings);
            UIApplication.SharedApplication.RegisterForRemoteNotifications();
        }
        else
        {
            UIRemoteNotificationType notificationTypes = UIRemoteNotificationType.Alert | UIRemoteNotificationType.Badge | UIRemoteNotificationType.Sound;
            UIApplication.SharedApplication.RegisterForRemoteNotificationTypes(notificationTypes);
        }
        UIApplication.SharedApplication.RegisterForRemoteNotifications();
    }

    public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
    {
        Hub = new SBNotificationHub(AppConstants.ListenConnectionString, AppConstants.NotificationHubName);

        // update registration with Azure Notification Hub
        Hub.UnregisterAll(deviceToken, (error) =>
        {
            if (error != null)
            {
                Debug.WriteLine($"Unable to call unregister {error}");
                return;
            }

            var tags = new NSSet(AppConstants.SubscriptionTags.ToArray());
            Hub.RegisterNative(deviceToken, tags, (errorCallback) =>
            {
                if (errorCallback != null)
                {
                    Debug.WriteLine($"RegisterNativeAsync error: {errorCallback}");
                }
            });

            var templateExpiration = DateTime.Now.AddDays(120).ToString(System.Globalization.CultureInfo.CreateSpecificCulture("en-US"));
            Hub.RegisterTemplate(deviceToken, "defaultTemplate", AppConstants.APNTemplateBody, templateExpiration, tags, (errorCallback) =>
            {
                if (errorCallback != null)
                {
                    if (errorCallback != null)
                    {
                        Debug.WriteLine($"RegisterTemplateAsync error: {errorCallback}");
                    }
                }
            });
        });

        // Firebase ios Registration
        Messaging.SharedInstance.ApnsToken = deviceToken;
        
       }
   // Process the notification when the app is open.
   
public override void ReceivedRemoteNotification(UIApplication application, NSDictionary userInfo)
    {
        ProcessNotification(userInfo, false);
        

    }   // End of the ReceiveRemoteNotification method

    

    // Process the notification when the app is closed.
    public override void DidReceiveRemoteNotification(UIApplication application, NSDictionary userInfo, Action<UIBackgroundFetchResult> completionHandler)
    {
        ProcessNotification(userInfo, false);            
        
    }


    void ProcessNotification(NSDictionary options, bool fromFinishedLaunching)
    {
        // make sure we have a payload
        if (options != null && options.ContainsKey(new NSString("aps")))
        {
            // get the APS dictionary and extract message payload. Message JSON will be converted
            // into a NSDictionary so more complex payloads may require more processing
            NSDictionary aps = options.ObjectForKey(new NSString("aps")) as NSDictionary;
            
            string payload = string.Empty;
            NSString payloadKey = new NSString("alert");
            
            if (aps.ContainsKey(payloadKey))
            {
                payload = aps[payloadKey].ToString();
            }

          
            
            if (!string.IsNullOrWhiteSpace(payload))
            {
                (App.Current.MainPage as MainPage)?.AddMessage(payload);
            }

        }
        else
        {
            Debug.WriteLine($"Received request to process notification but there was no payload.");
        } 
     } // End of the ProcessNotification method





}

}

Answer 2

无论应用程序在前台还是后台运行，都可以处理推送通知事件。按照这些步骤获取 DidReceiveRemoteNotification 总是被调用

1) 重写 AppDelegate.cs 中的 DidReceiveRemoteNotification 方法

public override void DidReceiveRemoteNotification(UIApplication application, NSDictionary userInfo, Action<UIBackgroundFetchResult> completionHandler)

2) 在 info.plist 中添加所需的后台模式 - remote-notification(value)

3) 将有效负载中的内容可用设置为 1

{
"aps" : {
    "alert" : {
        "title" : "Game Request",
        "body" : "Bob wants to play poker"
    },
    "badge" : 5,
    "content-available" : 1
}

}

Answer 3

你实现UserNotification了吗？如果您在 iOS 10+ 上部署您的项目，您可以尝试订阅FinishedLaunching(UIApplication application, NSDictionary launchOptions) 中的通知，例如：

if (UIDevice.CurrentDevice.CheckSystemVersion(10, 0))
{
    var authOptions = UNAuthorizationOptions.Alert | UNAuthorizationOptions.Badge | UNAuthorizationOptions.Sound;
    UNUserNotificationCenter.Current.RequestAuthorization(authOptions, (granted, error) => {
        Console.WriteLine(granted);
    });
    UNUserNotificationCenter.Current.Delegate = new MyNotificationCenterDelegate();
}

然后当通知到来并且应用程序在前台时，WillPresentNotification() 将被触发，这个句柄事件返回当通知到来时这个应用程序将响应哪个动作。终于可以在DidReceiveNotificationResponse()事件中获取userInfo了：

public class MyNotificationCenterDelegate : UNUserNotificationCenterDelegate
{
    public override void DidReceiveNotificationResponse(UNUserNotificationCenter center, UNNotificationResponse response, Action completionHandler)
    {
        completionHandler();
    }

    public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
    {
        completionHandler(UNNotificationPresentationOptions.Sound | UNNotificationPresentationOptions.Alert);

    }       
}

但是，如果您不想实现UserNotification，或者您只是使用键content-available true 推送一个静默远程通知，即使应用程序在前台，didReceiveRemoteNotification() 也会被触发。

Answer 4

AppDelegate 中的覆盖方法ReceivedRemoteNotification 或DidReceiveRemoteNotification，当您在前台收到推送通知时将被触发。

通过这种方法，您可以检查您的应用是否处于Active 状态，并根据它来处理您的通知。

if (UIApplication.SharedApplication.ApplicationState == UIApplicationState.Active) 
{
    //You app is in Foreground state.
    //Process the Pushnotification data, or show alert.
}

Apple's doc.

实施 应用程序（:didReceiveRemoteNotification:fetchCompletionHandler:) 尽可能使用这种方法而不是这种方法。如果你的代表 实现了这两种方法，应用程序对象调用 应用程序（:didReceiveRemoteNotification:fetchCompletionHandler:) 方法。

因此，如果您在 AppDelegate 中实现了这两种方法（ReceivedRemoteNotification 和 DidReceiveRemoteNotification），那么将调用 DidReceiveRemoteNotification 方法。