第一步发起通知.主要是date日期获取.可以在UIDatePicker或者calendar获取时间

mDatePicker.datePickerMode = .time
        let date = mDatePicker.date

        // 创建一个日期格式器
        let dformatter = DateFormatter()
        // 为日期格式器设置格式字符串
        dformatter.dateFormat = "HH:mma"
        // 使用日期格式器格式化日期、时间
        let datestr = dformatter.string(from: date)
        let message =  "每天 \(datestr)"
        NSLog(message)
        
        // 设置日期
        mTimeNotifyBtn.titleLabel?.text = message

        let types = UIUserNotificationType.alert
        let mySettings = UIUserNotificationSettings.init(types: types, categories: nil)
        UIApplication.shared.registerUserNotificationSettings(mySettings)
        let notification = UILocalNotification.init()
        notification.fireDate = NSDate.init(timeInterval: 10.0, since: date) as Date

        notification.alertBody = "您设置的练习时间到了"
        notification.alertTitle="请打开EnglishLeanger";
        notification.alertAction = "不要忘记学英语哦！";
        notification.repeatInterval=NSCalendar.Unit.day
        notification.applicationIconBadgeNumber=1;
        notification.soundName=UILocalNotificationDefaultSoundName;
        UIApplication.shared.scheduleLocalNotification(notification)

遇到的坑:
没有加入以下三行代码.提醒不出现
let types = UIUserNotificationType.alert
let mySettings = UIUserNotificationSettings.init(types: types, categories: nil)
UIApplication.shared.registerUserNotificationSettings(mySettings)

第二步,appdelegate里面设置

// 申请闹钟权限
    if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]){
        [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];
    }
    else {
        [application registerForRemoteNotificationTypes:UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeBadge];
    }
    //获取本地通知
    UILocalNotification * localNotify = [launchOptions objectForKey:UIApplicationLaunchOptionsLocalNotificationKey];

    if(localNotify){
        [self application:self didReceiveLocalNotification:localNotify];
    }else {

    }

    [UIApplication sharedApplication].applicationIconBadgeNumber = 0;

ps :遇到的bug 没有动态获取权限,也不会显示通知,而且不报错
注意小红点的展示applicationIconBadgeNumber
需要点击后取消通知,不然会一直重复不断通知代码如下:

-(void) application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification{
    [[UIApplication sharedApplication] cancelLocalNotification:notification];
}