項目中需要實現一個功能：收到特定類型的推送消息時，需要一端持續(xù)的響鈴加震動來提醒用戶适秩，普通的推送消息可以播放30s以內的提示音绊序，但是只會震動一下，用ios提供的Notification Service Extension 可以實現連續(xù)震動的效果秽荞，它不依賴于APP的存活狀態(tài)骤公，會最多存活30s的時間。具體實現方式如下：
1蚂会，創(chuàng)建Notification Service Extension擴展
創(chuàng)建完成后淋样，會自動生成以下兩個方法：
@interface NotificationService ()
@property (nonatomic, strong) void (^contentHandler)(UNNotificationContent *contentToDeliver);
@property (nonatomic, strong) UNMutableNotificationContent *bestAttemptContent;
//振動計時器
@property (nonatomic, strong, nullable) dispatch_source_t vibrationTimer;
@end
//收到推送消息后，會先執(zhí)行此方法
- (void)didReceiveNotificationRequest:(UNNotificationRequest *)request withContentHandler:(void (^)(UNNotificationContent * _Nonnull))contentHandler {
self.contentHandler = contentHandler;
self.bestAttemptContent = [request.content mutableCopy];
//開始震動
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
NSDictionary *pushDictionary = request.content.userInfo;
if([pushDictionary.allKeys containsObject:@"act"]){
NSInteger act = [pushDictionary[@"act"] integerValue];
//判斷是否是需要持續(xù)震動的通知類型
if(act == 4){
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
if (self.vibrationTimer) {
dispatch_cancel(self.vibrationTimer);
self.vibrationTimer = nil;
}
self.vibrationTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
dispatch_time_t start = dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC);
uint64_t interval = 1 * NSEC_PER_SEC;
dispatch_source_set_timer(self.vibrationTimer, start, interval, 0);
__block int times = 0;
//最多震動20次胁住，或者用戶點擊了推送的通知趁猴，則停止震動
dispatch_source_set_event_handler(self.vibrationTimer, ^{
self.contentHandler(self.bestAttemptContent);
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
times++;
NSUserDefaults *userDefault = [[NSUserDefaults alloc]initWithSuiteName:@"group.com.XXXXXX"];
NSString *status = [userDefault objectForKey:@"status"];
if(times >=20 ||[status isEqualToString:@"1"]){
dispatch_suspend(self.vibrationTimer);
dispatch_cancel(self.vibrationTimer);
}
});
dispatch_resume(self.vibrationTimer);
} else {
self.contentHandler(self.bestAttemptContent);
}
} else {
self.contentHandler(self.bestAttemptContent);
}
}
//如果在30s內還沒有執(zhí)行完想要執(zhí)行的任務，就會執(zhí)行這個方法
- (void)serviceExtensionTimeWillExpire {
// Called just before the extension will be terminated by the system.
// Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
if (self.vibrationTimer) {
dispatch_cancel(self.vibrationTimer);
self.vibrationTimer = nil;
}
self.contentHandler(self.bestAttemptContent);
}
這里有三點需要注意：
1彪见，只有調用self.contentHandler(self.bestAttemptContent);回調方法時儡司，推送的通知條消息才會出現在應用中，如果一直不回調該方法余指，等30s后捕犬，系統(tǒng)會自動調用- (void)serviceExtensionTimeWillExpire方法；
2：ios的服務擴展可以和app進行通信酵镜，有多種通信方式比如利用通知中心 CFNotificationCenterRef碉碉，或者socket，這里我選擇使用的是共享內存的方式：
NSUserDefaults *userDefault = [[NSUserDefaults alloc]initWithSuiteName:@"group.com.XXXXXX"];
NSString *status = [userDefault objectForKey:@"status"];
"group.com.XXXXXX" 需要自己創(chuàng)建一個共享內存的組名淮韭，當用戶點擊推送通知時,根據名稱找到當前內存垢粮，并設置一個值，在擴展中就能夠獲取該值了靠粪。
NSUserDefaults *userDefault = [[NSUserDefaults alloc]initWithSuiteName:@"group.com.net263.263Vision"];
[userDefault setObject:@"1" forKey:@"status"];
2,在擴展中蜡吧，使用NSTimer作為計時器時，自測無效(個人認為因為NSTimer運行依賴于NSRunLoop導致的)占键，無法觸發(fā)計時器運行昔善，使用dispatch_source_t能夠很好地運行。
3畔乙，要想在擴展中接收到推送的消息君仆，推送消息中還應該增加一個字段：“mutable-content”: 1
