Telephony

It may seem an overly obvious point to make, but the iPhone’s telephony system, which handles both phone calls and SMS messaging, can and will interrupt applications when the unit receives an incoming telephone call. Sure, users can suspend out of apps whenever they want on the iPhone, iPad, and iPod touch platforms, but only the iPhone has to deal with the kind of transition that’s forced by the system and not a choice by the user.

In addition to phone calls suspending your app, the user is able to open your app while on a call. When that happens, iOS adds a special top bar indicating the status of the call. Make sure to test your interface with the bar open as well as the bar being open then closing. The simulator lets you toggle ...

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