Smart Phone ! Iphone | Reading the device phone number HTTP etc

Does anyone know if one of these devices connect to the web whether their phone number can be read from a header 开发者_开发技巧or some other means?

Phone numbers don't go in HTTP headers. Your IP address will be visible to the web server, but that is it.

Edit: Ah, I see you want to get the phone number. This is a privacy issue for many people and the consensus is that the minor inconvenience of having to explicitly enter a phone number is worth the peace of mind that no one is stealing it.

What you can do is ask the user for their number, and store it along with the phone's UDID in a database. Next time your app connects to your server, you can send it the phone's UDID and look up the number from that.

No, it's not passed across.