iOS开发：如何在AppDelegate中获取FCM推送Payload里data字段的数据

没问题，我来帮你梳理下在AppDelegate中获取FCM推送里data字段数据的方法，分不同场景和两种常见处理方式来讲解：

这种是旧版的处理逻辑，针对App不同状态有不同的回调入口：

当App处于前台运行时 #

系统会触发application(_:didReceiveRemoteNotification:fetchCompletionHandler:)方法，你可以直接从传入的userInfo字典里提取data字段：

Swift示例： #

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
    // 提取FCM的data字段
    if let dataDict = userInfo["data"] as? [String: Any] {
        // 获取user_name值
        if let userName = dataDict["user_name"] as? String {
            print("获取到用户名称：\(userName)")
            // 这里可以做后续逻辑，比如更新UI、跳转页面等
        }
    }
    
    // 必须调用completionHandler告知系统处理结果
    completionHandler(.newData)
}

Objective-C示例： #

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
    // 提取FCM的data字段
    NSDictionary *dataDict = userInfo[@"data"];
    if (dataDict) {
        NSString *userName = dataDict[@"user_name"];
        if (userName) {
            NSLog(@"获取到用户名称：%@", userName);
            // 执行后续处理逻辑
        }
    }
    
    completionHandler(UIBackgroundFetchResultNewData);
}

当App处于后台/未启动时 #

如果用户是点击推送通知打开App，需要在application(_:didFinishLaunchingWithOptions:)方法中从launchOptions里获取推送数据：

Swift示例： #

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // 检查是否是通过点击推送通知启动的App
    if let remoteNotification = launchOptions?[.remoteNotification] as? [AnyHashable: Any] {
        if let dataDict = remoteNotification["data"] as? [String: Any] {
            if let userName = dataDict["user_name"] as? String {
                print("启动时获取到用户名称：\(userName)")
            }
        }
    }
    
    return true
}

Objective-C示例： #

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // 检查是否来自推送通知启动
    NSDictionary *remoteNotification = launchOptions[UIApplicationLaunchOptionsRemoteNotificationKey];
    if (remoteNotification) {
        NSDictionary *dataDict = remoteNotification[@"data"];
        if (dataDict) {
            NSString *userName = dataDict[@"user_name"];
            if (userName) {
                NSLog(@"启动时获取到用户名称：%@", userName);
            }
        }
    }
    
    return YES;
}

从iOS 10开始，苹果推荐用UNUserNotificationCenter统一处理推送，不管App处于前台还是后台，都能通过代理方法一站式处理：

首先要在didFinishLaunchingWithOptions中设置代理并请求推送权限：

Swift示例： #

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // 请求推送权限
    UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
        // 根据权限状态做对应处理
    }
    // 设置代理
    UNUserNotificationCenter.current().delegate = self
    
    return true
}

// 遵循UNUserNotificationCenterDelegate协议
extension AppDelegate: UNUserNotificationCenterDelegate {
    // App前台时，推送到达会触发这个方法
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        let userInfo = notification.request.content.userInfo
        if let dataDict = userInfo["data"] as? [String: Any] {
            if let userName = dataDict["user_name"] as? String {
                print("前台收到推送，用户名称：\(userName)")
            }
        }
        // 设置前台显示推送的方式（比如弹窗+声音）
        completionHandler([.alert, .sound])
    }
    
    // 用户点击推送通知时触发（不管App之前是后台还是未启动）
    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        let userInfo = response.notification.request.content.userInfo
        if let dataDict = userInfo["data"] as? [String: Any] {
            if let userName = dataDict["user_name"] as? String {
                print("点击推送，用户名称：\(userName)")
                // 这里可以做跳转页面等操作
            }
        }
        completionHandler()
    }
}

Objective-C示例： #

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // 请求推送权限
    [[UNUserNotificationCenter currentNotificationCenter] requestAuthorizationWithOptions:(UNAuthorizationOptionAlert | UNAuthorizationOptionSound | UNAuthorizationOptionBadge) completionHandler:^(BOOL granted, NSError * _Nullable error) {
        // 处理权限请求结果
    }];
    // 设置代理
    [[UNUserNotificationCenter currentNotificationCenter] setDelegate:self];
    
    return YES;
}

// 遵循UNUserNotificationCenterDelegate协议
@interface AppDelegate () <UNUserNotificationCenterDelegate>
@end

@implementation AppDelegate
// 前台收到推送时触发
- (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions))completionHandler {
    NSDictionary *userInfo = notification.request.content.userInfo;
    NSDictionary *dataDict = userInfo[@"data"];
    if (dataDict) {
        NSString *userName = dataDict[@"user_name"];
        if (userName) {
            NSLog(@"前台收到推送，用户名称：%@", userName);
        }
    }
    // 设置前台显示选项
    completionHandler(UNNotificationPresentationOptionAlert | UNNotificationPresentationOptionSound);
}

// 用户点击推送时触发
- (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void (^)(void))completionHandler {
    NSDictionary *userInfo = response.notification.request.content.userInfo;
    NSDictionary *dataDict = userInfo[@"data"];
    if (dataDict) {
        NSString *userName = dataDict[@"user_name"];
        if (userName) {
            NSLog(@"点击推送，用户名称：%@", userName);
        }
    }
    completionHandler();
}
@end

需要注意：你的Payload同时包含notification和data字段，这种混合类型的推送在App后台时，data字段会自动附加到通知的userInfo中，所以上面的方法都能正常获取到数据。

内容的提问来源于stack exchange，提问作者Yunusbek Sadullaev