MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification
Posted when the value returned by the Cansendtext() class method has changed.
Declaration
extern NSString * const MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification;Discussion
Upon receiving this notification, query its userInfo dictionary with the MFMessageComposeViewControllerTextMessageAvailabilityKey key. If the availability of text message sending has changed, your app should invalidate caches and update its user interface as appropriate.