Why doesn't Apple's SMS show phone book contacts?

By default, IOS8 is set to display your recent contacts.

The method is as follows:

1. Open Settings and find "Mail, Address Book, Calendar" in Settings.

2. Click "Mail, Address Book, Calendar" to enter this submenu. You can see that "Display in the application switcher" is set to "On" by default.

3. Click Show in Application Switcher.

4. Open Phone Favorites and Recent Calls at the same time.