在iOS前台应用程序时获取推送通知

要在应用程序处于前台时显示横幅消息，请使用以下方法。

iOS 10，斯威夫特 3/4：

// This method will be called when app received push notifications in foreground
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) 
{
    completionHandler([.alert, .badge, .sound])
}

iOS 10，斯威夫特 2.3：

@available(iOS 10.0, *)
func userNotificationCenter(center: UNUserNotificationCenter, willPresentNotification notification: UNNotification, withCompletionHandler completionHandler: (UNNotificationPresentationOptions) -> Void)
{
    //Handle the notification
    completionHandler(
       [UNNotificationPresentationOptions.Alert,
        UNNotificationPresentationOptions.Sound,
        UNNotificationPresentationOptions.Badge])
}

您还必须将您的应用代理注册为通知中心的代理：

import UserNotifications

// snip!

class AppDelegate : UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate

// snip!

   func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

      // set the delegate in didFinishLaunchingWithOptions
      UNUserNotificationCenter.current().delegate = self
      ...
   }

下面的代码将为您工作：

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo  {
    application.applicationIconBadgeNumber = 0;             
    //self.textView.text = [userInfo description];
    // We can determine whether an application is launched as a result of the user tapping the action
    // button or whether the notification was delivered to the already-running application by examining
    // the application state.

    if (application.applicationState == UIApplicationStateActive) {                
        // Nothing to do if applicationState is Inactive, the iOS already displayed an alert view.                
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Did receive a Remote Notification" message:[NSString stringWithFormat:@"Your App name received this notification while it was running:n%@",[[userInfo objectForKey:@"aps"] objectForKey:@"alert"]]delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alertView show];          
    }    
}

对于任何可能感兴趣的人，我最终创建了一个自定义视图，该视图看起来像顶部的系统推送横幅，但添加了一个关闭按钮（蓝色小 X）和一个用于点击消息以进行自定义操作的选项。它还支持在用户有时间阅读/关闭旧通知之前到达多个通知的情况（不限制可以堆积多少......）

Link to GitHub: AGPushNote

用法基本在线：

[AGPushNoteView showWithNotificationMessage:@"John Doe sent you a message!"];

它在 iOS7 上看起来像这样（iOS6 具有 iOS6 的外观......）

目标 C

对于 iOS 10 ，我们需要集成 willPresentNotification 方法以在 foreground 中显示通知横幅。

如果应用程序处于前台模式（活动）

- (void)userNotificationCenter:(UNUserNotificationCenter* )center willPresentNotification:(UNNotification* )notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler {
    NSLog( @"Here handle push notification in foreground" ); 
    //For notification Banner - when app in foreground

    completionHandler(UNNotificationPresentationOptionAlert);

    // Print Notification info
    NSLog(@"Userinfo %@",notification.request.content.userInfo);
}

Xcode 10 斯威夫特 4.2

当您的应用程序处于前台时显示推送通知 -

第 1 步： 在 AppDelegate 类中添加委托 UNUserNotificationCenterDelegate。

class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {

第 2 步： 设置 UNUserNotificationCenter 委托

let notificationCenter = UNUserNotificationCenter.current()
notificationCenter.delegate = self

第 3 步： 这一步将允许您的应用在前台显示推送通知

func userNotificationCenter(_ center: UNUserNotificationCenter,
                                willPresent notification: UNNotification,
                                withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        completionHandler([.alert, .sound])

    }

第 4 步：此​​步骤是可选的。检查您的应用程序是否在前台，如果它在前台，则显示 Local PushNotification。

func application(_ application: UIApplication,didReceiveRemoteNotification userInfo: [AnyHashable: Any],fetchCompletionHandler completionHandler:@escaping (UIBackgroundFetchResult) -> Void) {

        let state : UIApplicationState = application.applicationState
        if (state == .inactive || state == .background) {
            // go to screen relevant to Notification content
            print("background")
        } else {
            // App is in UIApplicationStateActive (running in foreground)
            print("foreground")
            showLocalNotification()
        }
    }

本地通知功能 -

fileprivate func showLocalNotification() {

        //creating the notification content
        let content = UNMutableNotificationContent()

        //adding title, subtitle, body and badge
        content.title = "App Update"
        //content.subtitle = "local notification"
        content.body = "New version of app update is available."
        //content.badge = 1
        content.sound = UNNotificationSound.default()

        //getting the notification trigger
        //it will be called after 5 seconds
        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)

        //getting the notification request
        let request = UNNotificationRequest(identifier: "SimplifiedIOSNotification", content: content, trigger: trigger)

        //adding the notification to notification center
        notificationCenter.add(request, withCompletionHandler: nil)
    }

对于 Swift 5

1) 使用 UNUserNotificationCenterDelegate 向 AppDelegate 确认委托

2) UNUserNotificationCenter.current().delegate = self 中的 didFinishLaunch

3) 在 AppDelegate 中实现下面的方法。

func userNotificationCenter(_ center: UNUserNotificationCenter,
                                willPresent notification: UNNotification,
                                withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
     print("Push notification received in foreground.")
     completionHandler([.alert, .sound, .badge])
}

而已！

如果应用程序在前台运行，iOS 将不会显示通知横幅/警报。这是设计使然。您必须编写一些代码来处理您的应用程序在前台接收通知的情况。您应该以最合适的方式显示通知（例如，将徽章编号添加到 UITabBar 图标、模拟通知中心横幅等）。

您可以创建自己的模仿横幅警报的通知。

一种方法是创建一个看起来像横幅的自定义 uiview，并且可以动画和响应触摸。考虑到这一点，您可以创建具有更多功能的更好的横幅。

或者你可以寻找一个 api 为你做这件事，并将它们作为 podfiles 添加到你的项目中。

这是我用过的一对：

https://github.com/terryworona/TWMessageBarManager

https://github.com/toursprung/TSMessages

这是当应用程序处于活动状态（前台或打开）时接收推送通知的代码。 UNUserNotificationCenter documentation

@available(iOS 10.0, *)
func userNotificationCenter(center: UNUserNotificationCenter, willPresentNotification notification: UNNotification, withCompletionHandler completionHandler: (UNNotificationPresentationOptions) -> Void)
{
     completionHandler([UNNotificationPresentationOptions.Alert,UNNotificationPresentationOptions.Sound,UNNotificationPresentationOptions.Badge])
}

如果需要访问通知的userInfo 使用代码： notification.request.content.userInfo