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参考资料：
http://www.cocoachina.com/ios/20160628/16833.html
https://onevcat.com/2016/08/notification/
http://www.cnblogs.com/lidongq/p/5968923.html
https://developer.apple.com/reference/usernotifications/unnotificationattachment
http://www.jianshu.com/p/2f3202b5e758
http://www.cocoachina.com/ios/20161021/17820.html
https://www.jianshu.com/p/559fb72a99d0