前言

上一篇文章介紹了UILocalNotification的使用，這篇文章主要介紹一下UNUserNotificationCenter的使用。UILocalNotification現(xiàn)在雖然還能使用，但是也已經(jīng)是要被廢棄不用的方法了，而本篇所要介紹的UNUserNotificationCenter就是被棄用方法的替代品。

UNUserNotificationCenter的使用

還是那個(gè)思路，只知道使用UNUserNotificationCenter來(lái)實(shí)現(xiàn)本地推送，具體怎么實(shí)現(xiàn)不知道。

我們?cè)谏弦黄恼轮兴鶖⑹龅拇a在Xcode里雖然能執(zhí)行，但是由于那時(shí)蘋果棄用的方法，所以會(huì)報(bào)出一大堆惡心的警告，我們就來(lái)看一下警告，就能夠從中知道該怎么使用UNUserNotificationCenter了。

1. 注冊(cè)通知

注冊(cè)通知

關(guān)于注冊(cè)通知的這個(gè)方法中對(duì)于警告的類我都在圖中標(biāo)注了，警告的意思就是說(shuō)某某方法已經(jīng)被棄用，讓使用UserNotifications框架中的某某方法代替。那么我們就用新的類來(lái)注冊(cè)一下通知。(既然是新的框架，必然要引入頭文件咯，不然是會(huì)報(bào)錯(cuò)的喲)

上圖中出現(xiàn)了UNUserNotificationCenter新類和-[UNUserNotificationCenter requestAuthorizationWithOptions:completionHandler:]、-[UNUserNotificationCenter setNotificationCategories:]兩個(gè)示例方法，先查看一下新類的構(gòu)造。

@interface UNUserNotificationCenter : NSObject

// The delegate can only be set from an application
@property (NS_NONATOMIC_IOSONLY, nullable, weak) id <UNUserNotificationCenterDelegate> delegate;

// Returns YES if the current device supports content extensions
@property (NS_NONATOMIC_IOSONLY, readonly) BOOL supportsContentExtensions;

// The UNUserNotificationCenter for the current application
+ (UNUserNotificationCenter *)currentNotificationCenter;

- (instancetype)init NS_UNAVAILABLE;

// User authorization is required for applications to notify the user using UNUserNotificationCenter via both local and remote notifications.
- (void)requestAuthorizationWithOptions:(UNAuthorizationOptions)options completionHandler:(void (^)(BOOL granted, NSError *__nullable error))completionHandler;

// Notification categories can be used to choose which actions will be displayed on which notifications.
- (void)setNotificationCategories:(NSSet<UNNotificationCategory *> *)categories __TVOS_PROHIBITED;
- (void)getNotificationCategoriesWithCompletionHandler:(void(^)(NSSet<UNNotificationCategory *> *categories))completionHandler __TVOS_PROHIBITED;

// The application's user notification settings
- (void)getNotificationSettingsWithCompletionHandler:(void(^)(UNNotificationSettings *settings))completionHandler;

// Notification requests can be scheduled to notify the user via time and location. See UNNotificationTrigger for more information. Calling -addNotificationRequest: will replace an existing notification request with the same identifier. A notification request with the identifier as an existing delivered notifications will alert for the new notification request and replace the existing delivered notification when it is triggered. The number of pending notification requests that may be scheduled by an application at any one time is limited by the system.
- (void)addNotificationRequest:(UNNotificationRequest *)request withCompletionHandler:(nullable void(^)(NSError *__nullable error))completionHandler;

// Notification requests that are waiting for their trigger to fire
- (void)getPendingNotificationRequestsWithCompletionHandler:(void(^)(NSArray<UNNotificationRequest *> *requests))completionHandler;
- (void)removePendingNotificationRequestsWithIdentifiers:(NSArray<NSString *> *)identifiers;
- (void)removeAllPendingNotificationRequests;

// Notifications that have been delivered and remain in Notification Center. Notifiations triggered by location cannot be retrieved, but can be removed.
- (void)getDeliveredNotificationsWithCompletionHandler:(void(^)(NSArray<UNNotification *> *notifications))completionHandler __TVOS_PROHIBITED;
- (void)removeDeliveredNotificationsWithIdentifiers:(NSArray<NSString *> *)identifiers __TVOS_PROHIBITED;
- (void)removeAllDeliveredNotifications __TVOS_PROHIBITED;

@end

從以上的構(gòu)造中我們可以知道的是，UNUserNotificationCenter類繼承自NSObject類，還有一個(gè)UNUserNotificationCenterDelegate類型的代理，一個(gè)類方法+ (UNUserNotificationCenter *)currentNotificationCenter;用于返回當(dāng)前應(yīng)用的通知中心；至于下面的那么多示例方法，其中包括注冊(cè)通知的方法、設(shè)置categories的方法、獲取通知的設(shè)置的方法、添加通知的方法、移除通知的方法等等。

因?yàn)槲覀兪且?cè)通知，故先仔細(xì)看一下注冊(cè)通知這個(gè)方法。

- (void)requestAuthorizationWithOptions:(UNAuthorizationOptions)options completionHandler:(void (^)(BOOL granted, NSError *__nullable error))completionHandler;

該方法需要一個(gè)UNAuthorizationOptions類型的參數(shù)，點(diǎn)進(jìn)去看一下這個(gè)類型，發(fā)現(xiàn)這個(gè)竟然是個(gè)枚舉類型的，跟上篇文章中設(shè)置通知方法中的那個(gè)參數(shù)類似，只是換了一個(gè)名稱而已。至于后面的blockcompletionHandler，就是注冊(cè)結(jié)果的一個(gè)block。

typedef NS_OPTIONS(NSUInteger, UNAuthorizationOptions) {
    UNAuthorizationOptionBadge   = (1 << 0),
    UNAuthorizationOptionSound   = (1 << 1),
    UNAuthorizationOptionAlert   = (1 << 2),
    UNAuthorizationOptionCarPlay = (1 << 3),
} __IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0);

接下來(lái)我們就可以順利的寫出來(lái)注冊(cè)通知的代碼了，如下：

    UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
    center.delegate = self;
    [center requestAuthorizationWithOptions:(UNAuthorizationOptionSound | UNAuthorizationOptionAlert | UNAuthorizationOptionBadge) completionHandler:^(BOOL granted, NSError * _Nullable error) {
    }];

這里還有個(gè)代理忘了說(shuō)了，center的代理方法有兩個(gè)，如下：

@protocol UNUserNotificationCenterDelegate <NSObject>

@optional

// The method will be called on the delegate only if the application is in the foreground. If the method is not implemented or the handler is not called in a timely manner then the notification will not be presented. The application can choose to have the notification presented as a sound, badge, alert and/or in the notification list. This decision should be based on whether the information in the notification is otherwise visible to the user.
- (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler __IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0);

// The method will be called on the delegate when the user responded to the notification by opening the application, dismissing the notification or choosing a UNNotificationAction. The delegate must be set before the application returns from application:didFinishLaunchingWithOptions:.
- (void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)(void))completionHandler __IOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0) __TVOS_PROHIBITED;

@end

這個(gè)代理方法可以根據(jù)項(xiàng)目實(shí)際需求看是否需要了。

2. 設(shè)置通知

還是老路子，先來(lái)看一下發(fā)送通知的報(bào)黃警告內(nèi)容。

發(fā)送通知警告

警告的內(nèi)容明確說(shuō)了- scheduleLocalNotification:這個(gè)方法被棄用了，要讓使用-[UNUserNotificationCenter addNotificationRequest:withCompletionHandler:]來(lái)代替，這么一看，這不就是剛才注冊(cè)通知時(shí)候的那個(gè)UNUserNotificationCenter類中的示例方法嘛，這下問(wèn)題就更好解決了，方法所在類都了解了，剩余的就是看參數(shù)咯。

- (void)addNotificationRequest:(UNNotificationRequest *)request withCompletionHandler:(nullable void(^)(NSError *__nullable error))completionHandler;

從上面的函數(shù)中我們可以知道，該實(shí)例方法需要一個(gè)UNNotificationRequest類型的參數(shù)。點(diǎn)進(jìn)去看看它究竟是個(gè)什么鬼。

@interface UNNotificationRequest : NSObject <NSCopying, NSSecureCoding>

// The unique identifier for this notification request. It can be used to replace or remove a pending notification request or a delivered notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *identifier;

// The content that will be shown on the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) UNNotificationContent *content;

// The trigger that will or did cause the notification to be delivered. No trigger means deliver now.
@property (NS_NONATOMIC_IOSONLY, readonly, copy, nullable) UNNotificationTrigger *trigger;

+ (instancetype)requestWithIdentifier:(NSString *)identifier content:(UNNotificationContent *)content trigger:(nullable UNNotificationTrigger *)trigger;

- (instancetype)init NS_UNAVAILABLE;

@end

進(jìn)去一看，哇塞，這么簡(jiǎn)短，只有短短的三十行代碼(包含注釋)，知道了這個(gè)類是集成自NSObject類，還有三個(gè)成員變量和一個(gè)類方法的初始方法和一個(gè)示例方法的初始化方法。我們?cè)诔跏蓟臅r(shí)候肯定就用類方法初始化啊，這樣更簡(jiǎn)單，因?yàn)樵陬惙椒ㄖ幸呀?jīng)把必須的參數(shù)都給包含了，不用使用- init方法之后再依次的給其成員變量賦值。

• 類方法+ (instancetype)requestWithIdentifier:(NSString *)identifier content:(UNNotificationContent *)content trigger:(nullable UNNotificationTrigger *)trigger;

這個(gè)方法中除了需要一個(gè)字符串的標(biāo)識(shí)符identifier以外，還需要UNNotificationContent類型的content以及UNNotificationTrigger類型的trigger。接下來(lái)我們就來(lái)仔細(xì)看一下這兩個(gè)參數(shù)。

A. UNNotificationContent類型的content

先來(lái)看一下類組成

@interface UNNotificationContent : NSObject <NSCopying, NSMutableCopying, NSSecureCoding>

// Optional array of attachments.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSArray <UNNotificationAttachment *> *attachments __TVOS_PROHIBITED;

// The application badge number.
@property (NS_NONATOMIC_IOSONLY, readonly, copy, nullable) NSNumber *badge;

// The body of the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *body __TVOS_PROHIBITED;

// The identifier for a registered UNNotificationCategory that will be used to determine the appropriate actions to display for the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *categoryIdentifier __TVOS_PROHIBITED;

// The launch image that will be used when the app is opened from the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *launchImageName __TVOS_PROHIBITED;

// The sound that will be played for the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy, nullable) UNNotificationSound *sound __TVOS_PROHIBITED;

// The subtitle of the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *subtitle __TVOS_PROHIBITED;

// The unique identifier for the thread or conversation related to this notification request. It will be used to visually group notifications together.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *threadIdentifier __TVOS_PROHIBITED;

// The title of the notification.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSString *title __TVOS_PROHIBITED;

// Apps can set the userInfo for locally scheduled notification requests. The contents of the push payload will be set as the userInfo for remote notifications.
@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSDictionary *userInfo __TVOS_PROHIBITED;

@end

__IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
@interface UNMutableNotificationContent : UNNotificationContent

// Optional array of attachments.
@property (NS_NONATOMIC_IOSONLY, copy) NSArray <UNNotificationAttachment *> *attachments __TVOS_PROHIBITED;

// The application badge number. nil means no change. 0 to hide.
@property (NS_NONATOMIC_IOSONLY, copy, nullable) NSNumber *badge;

// The body of the notification. Use -[NSString localizedUserNotificationStringForKey:arguments:] to provide a string that will be localized at the time that the notification is presented.
@property (NS_NONATOMIC_IOSONLY, copy) NSString *body __TVOS_PROHIBITED;

// The identifier for a registered UNNotificationCategory that will be used to determine the appropriate actions to display for the notification.
@property (NS_NONATOMIC_IOSONLY, copy) NSString *categoryIdentifier __TVOS_PROHIBITED;

// The launch image that will be used when the app is opened from the notification.
@property (NS_NONATOMIC_IOSONLY, copy) NSString *launchImageName __TVOS_PROHIBITED;

// The sound that will be played for the notification.
@property (NS_NONATOMIC_IOSONLY, copy, nullable) UNNotificationSound *sound __TVOS_PROHIBITED;

// The subtitle of the notification. Use -[NSString localizedUserNotificationStringForKey:arguments:] to provide a string that will be localized at the time that the notification is presented.
@property (NS_NONATOMIC_IOSONLY, copy) NSString *subtitle __TVOS_PROHIBITED;

// The unique identifier for the thread or conversation related to this notification request. It will be used to visually group notifications together.
@property (NS_NONATOMIC_IOSONLY, copy) NSString *threadIdentifier __TVOS_PROHIBITED;

// The title of the notification. Use -[NSString localizedUserNotificationStringForKey:arguments:] to provide a string that will be localized at the time that the notification is presented.
@property (NS_NONATOMIC_IOSONLY, copy) NSString *title __TVOS_PROHIBITED;

// Apps can set the userInfo for locally scheduled notification requests. The contents of the push payload will be set as the userInfo for remote notifications.
@property (NS_NONATOMIC_IOSONLY, copy) NSDictionary *userInfo;

@end

這個(gè)是代碼量相比較上一個(gè)類是多了很多，但是再仔細(xì)看一下，這是兩個(gè)類，第一個(gè)類UNNotificationContent是繼承自NSObject類，第二個(gè)類 UNMutableNotificationContent繼承自UNNotificationContent，有沒(méi)有很熟悉的感覺(jué)，這不就是跟NSArray和NSMutableArray的關(guān)系一樣嘛，仔細(xì)看一下成員變量都基本上相同，唯一的區(qū)別在于前者的成員變量的是readonly的，后者則沒(méi)有限制，那么我們要構(gòu)造這個(gè)參數(shù)就可以直接使用后者可變的UNMutableNotificationContent來(lái)構(gòu)造了。至于成員變量無(wú)非就是設(shè)置推送內(nèi)容、聲音、圖片等的，唯一值得一提的是，這里的聲音又單獨(dú)封裝了一個(gè)類UNNotificationSound來(lái)實(shí)現(xiàn)，其中包含有一個(gè)默認(rèn)聲音的+ (instancetype)defaultSound;類方法和可以自定義聲音+ (instancetype)soundNamed:(NSString *)name __WATCHOS_PROHIBITED;類方法以及一個(gè)- init初始化方法。至于使用那就不用多說(shuō)了吧。

B. UNNotificationTrigger類型的trigger

先來(lái)看一下類構(gòu)造

@interface UNNotificationTrigger : NSObject <NSCopying, NSSecureCoding>

@property (NS_NONATOMIC_IOSONLY, readonly) BOOL repeats;

- (instancetype)init NS_UNAVAILABLE;

@end

// UNPushNotificationTrigger can be sent from a server using Apple Push Notification Service.
__IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
@interface UNPushNotificationTrigger : UNNotificationTrigger

@end

// UNTimeIntervalNotificationTrigger can be scheduled on the device to notify after the time interval, and optionally repeat.
__IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
@interface UNTimeIntervalNotificationTrigger : UNNotificationTrigger

@property (NS_NONATOMIC_IOSONLY, readonly) NSTimeInterval timeInterval;

+ (instancetype)triggerWithTimeInterval:(NSTimeInterval)timeInterval repeats:(BOOL)repeats;

- (nullable NSDate *)nextTriggerDate;

@end

// UNCalendarNotificationTrigger can be scheduled on the device to notify based on date and time values, and optionally repeat. For example, if a notification should be delivered at the next 8:00 AM then set the 'hour' property of dateComponents to 8. If the notification should be delivered every day at 8:00 AM then set repeats to YES.
__IOS_AVAILABLE(10.0) __TVOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0)
@interface UNCalendarNotificationTrigger : UNNotificationTrigger

@property (NS_NONATOMIC_IOSONLY, readonly, copy) NSDateComponents *dateComponents;

// The next date is calculated using matching date components.
+ (instancetype)triggerWithDateMatchingComponents:(NSDateComponents *)dateComponents repeats:(BOOL)repeats;

- (nullable NSDate *)nextTriggerDate;

@end

// UNLocationNotificationTrigger can be scheduled on the device to notify when the user enters or leaves a geographic region. The identifier on CLRegion must be unique. Scheduling multiple UNNotificationRequests with different regions containing the same identifier will result in undefined behavior. The number of UNLocationNotificationTriggers that may be scheduled by an application at any one time is limited by the system. Applications must have "when-in-use" authorization through CoreLocation. See the CoreLocation documentation for more information.
__IOS_AVAILABLE(10.0) __WATCHOS_AVAILABLE(3.0) __TVOS_PROHIBITED
@interface UNLocationNotificationTrigger : UNNotificationTrigger

@property (NS_NONATOMIC_IOSONLY, readonly, copy) CLRegion *region;

+ (instancetype)triggerWithRegion:(CLRegion *)region repeats:(BOOL)repeats __WATCHOS_PROHIBITED;

@end

猛地一看貌似也很多的樣子，但是仔細(xì)一看就發(fā)現(xiàn)了端倪：
這里不僅僅是UNNotificationTrigger一個(gè)類，還包含了以下四個(gè)類：

1. // UNPushNotificationTrigger can be sent from a server using Apple Push Notification Service.
   UNPushNotificationTrigger
   

2. // UNTimeIntervalNotificationTrigger can be scheduled on the device to notify after the time interval, and optionally repeat.
   UNTimeIntervalNotificationTrigger
   

3. // UNCalendarNotificationTrigger can be scheduled on the device to notify based on date and time values, and optionally repeat. For example, if a notification should be delivered at the next 8:00 AM then set the 'hour' property of dateComponents to 8. If the notification should be delivered every day at 8:00 AM then set repeats to YES.
   UNCalendarNotificationTrigger
   

4. // UNLocationNotificationTrigger can be scheduled on the device to notify when the user enters or leaves a geographic region. The identifier on CLRegion must be unique. Scheduling multiple UNNotificationRequests with different regions containing the same identifier will result in undefined behavior. The number of UNLocationNotificationTriggers that may be scheduled by an application at any one time is limited by the system. Applications must have "when-in-use" authorization through CoreLocation. See the CoreLocation documentation for more information.
   UNLocationNotificationTrigger
   

值得一說(shuō)的是，這四個(gè)類全部都是繼承自UNNotificationTrigger類，也就是說(shuō)添加推送的方法參數(shù)trigger中，我們無(wú)論是使用UNNotificationTrigger亦或者是其子類都可以。

OK，所有的介紹到現(xiàn)在為止，我們已經(jīng)能夠?qū)懗鰜?lái)發(fā)送通知的代碼了，如下：

            UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
            UNMutableNotificationContent *content = [[UNMutableNotificationContent alloc] init];
            content.badge = [NSNumber numberWithInt:1];
            content.title = @"磨蹭";
            content.body = @"不要磨蹭了你個(gè)懶蛋";
            content.sound = [UNNotificationSound defaultSound];
            // 間隔多久推送一次
            // 當(dāng)前時(shí)間之后的沒(méi)分鐘推送一次(如果重復(fù)的話時(shí)間要大于等于60s)
//            UNTimeIntervalNotificationTrigger *trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:60 repeats:YES];
            // 定時(shí)推送
            NSDateComponents *dateCom = [[NSDateComponents alloc] init];
            // 每天下午兩點(diǎn)五十五分推送
            dateCom.hour = 14;
            dateCom.minute = 55;
            UNCalendarNotificationTrigger *trigger = [UNCalendarNotificationTrigger triggerWithDateMatchingComponents:dateCom repeats:YES];
            
            UNNotificationRequest *notificationRequest = [UNNotificationRequest requestWithIdentifier:@"request1" content:content trigger:trigger];
            [center addNotificationRequest:notificationRequest withCompletionHandler:^(NSError * _Nullable error) {
            }];

總結(jié)

新類UNUserNotificationCenter實(shí)現(xiàn)推送相比較于上篇文章中介紹的UILocalNotification類來(lái)說(shuō)從內(nèi)容上來(lái)說(shuō)，新類是將原先的類進(jìn)行了更加細(xì)致化的封裝并將新類放在新的框架UserNotifications中，各個(gè)類功能分工更加明確，使用起來(lái)也更加簡(jiǎn)便。

友情鏈接：iOS8 本地推送 UILocalNotification

如有不足之處，歡迎指出。