How to protect contacts of my application, such as Facebook

Question

When you try to find contacts from your device, you usually get contacts created by all applications except Facebook. This question describes this.

So, what do I need to do when I store contacts through my applications (using ContactsContract?) So that other applications will not be able to get it through ContactsContract .. but they are still available for the device’s contacts app ... or in the applications that I choose?

Answer 1

Facebook contacts are synced using a different contact API implementation. Google used a special case for this, but does not do this anymore. The various equipment manufacturers that support it are customizing the Contacts application for this specific use. That's why Facebook contact sync works on most phones except the Nexus series. These are private implementations, but I'm sure it could be reverse engineering if you are ready to sort a lot of confusing codes.