iOS推送注册后device token未在NSLog打印，如何修改代码实现正常打印？

你当前的代码存在两个核心问题导致回调不触发：

1. 调用registerForRemoteNotifications的时机错误：你在注册通知配置后立刻调用了远程推送注册，此时用户还未完成授权弹窗的选择，只有用户同意授权后调用注册接口才会触发回调
2. 未适配iOS10及以上系统的推送接口：旧的registerUserNotificationSettings接口在iOS10后已经废弃，新版系统需要使用UserNotifications框架的新接口实现注册

第一步：导入依赖并添加代理 #

在AppDelegate.m文件头部导入UserNotifications框架，同时在类扩展中遵守UNUserNotificationCenterDelegate协议：

#import <UserNotifications/UserNotifications.h>

@interface AppDelegate () <UNUserNotificationCenterDelegate>
@end

第二步：修改注册逻辑 #

将didFinishLaunchingWithOptions中的推送注册逻辑替换为以下适配多版本的代码，把远程注册动作放到授权成功的回调中：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions
{
    // 适配iOS10+推送接口
    if (@available(iOS 10.0, *)) {
        UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
        center.delegate = self;
        [center requestAuthorizationWithOptions:(UNAuthorizationOptionBadge | UNAuthorizationOptionSound | UNAuthorizationOptionAlert) completionHandler:^(BOOL granted, NSError * _Nullable error) {
            if (granted) {
                // 授权成功后再注册远程推送，切回主线程调用避免异常
                dispatch_async(dispatch_get_main_queue(), ^{
                    [application registerForRemoteNotifications];
                });
            } else if (error) {
                NSLog(@"推送授权失败: %@", error);
            }
        }];
    } else if (@available(iOS 8.0, *)) {
        // iOS8-iOS9系统适配
        [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge) categories:nil]];
    } else {
        // iOS8以下系统适配
        [[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert)];
    }

    // 原有启动推送处理逻辑保留
    if (launchOptions != nil) {
        NSDictionary* dictionary = [launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
        if (dictionary != nil) {
            NSLog(@"Launched from push notification: %@", dictionary);
        }
    }

    return YES;
}

// 适配iOS8-iOS9的授权回调，用户选择后再注册远程推送
- (void)application:(UIApplication *)application didRegisterUserNotificationSettings:(UIUserNotificationSettings *)notificationSettings NS_DEPRECATED_IOS(8_0, 10_0) {
    if (notificationSettings.types != UIUserNotificationTypeNone) {
        [application registerForRemoteNotifications];
    }
}

// 原有token回调和失败回调保留即可
- (void)application:(UIApplication*)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData*)deviceToken {
    NSLog(@"My token is: %@", deviceToken);
    // 如果需要转成无特殊字符的字符串可以用以下代码
    // NSString *token = [[deviceToken description] stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"<>"]];
    // token = [token stringByReplacingOccurrencesOfString:@" " withString:@""];
    // NSLog(@"格式化后的token: %@", token);
}

- (void)application:(UIApplication*)application didFailToRegisterForRemoteNotificationsWithError:(NSError*)error {
    NSLog(@"Failed to get token, error: %@", error);
}

必要排查项 #

修改代码后如果还是没有回调，请检查以下配置：

• 必须使用真机测试，模拟器无法获取device token
• 工程的Signing & Capabilities标签页中必须添加Push Notifications能力
• 你使用的开发者证书必须已经开启推送服务权限
• 授权弹窗弹出后必须点击「允许」，如果之前点击过拒绝，需要到系统设置-对应App-通知中手动开启允许通知权限

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