iOS10起有callkit可以俾app整來電辨識、blacklist、whitelist
你未用過芝麻來電定未升iOS10
冇callkit嘅iOS根本殘廢
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要手動入封鎖的聯絡人
https://developer.apple.com/documentation/callkit
Identifying Incoming Callers
When a phone receives an incoming call, the system first consults the user’s contacts to find a matching phone number. If no match is found, the system then consults
your app’s Call Directory extension to find a matching entry to identify the phone number. This is useful for applications that maintain a contact list for a user that’s separate from the system contacts, such as a social network, or for identifying incoming calls that may be initiated from within the app,
such as for customer service support or a delivery notification.