下面这个示例是在前台中也能收到声音推送,要想在前台中不推送声音,只需要设置为completionHandler(UNNotificationPresentationOptionBadge|UNNotificationPresentationOptionAlert);

- (void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions))completionHandler{
   // 需要执行这个方法，选择是否提醒用户，有Badge、Sound、Alert三种类型可以设置
    completionHandler(UNNotificationPresentationOptionBadge| UNNotificationPresentationOptionSound|UNNotificationPresentationOptionAlert);

}