CXPlayDTMFCallAction
An encapsulation of the act of playing a dual tone multifrequency (DTMF) sequence.
Declaration
class CXPlayDTMFCallActionOverview
CXPlayDTMFCallAction is a concrete subclass of CXCallAction. Whenever digits are transmitted during a call, whether from a user interacting with a number pad or following a hard or soft pause, the provider sends provider(_:perform:) to its delegate. The provider’s delegate calls the fulfill() method to indicate that the action was successfully performed.
The provider sends provider(_:perform:) for successive actions only after the current action is fulfilled. When interacting with the number pad, each entered digit constitutes its own action. Digits following a hard or soft pause, however, are passed to provider(_:perform:) as a single string of digits. For example, if a user taps the 4 button on the number pad, followed by the 2 button, the delegate is sent provider(_:perform:) for the digit 4 and waits for the action to be fulfilled; after the action is fulfilled, the delegate is sent provider(_:perform:) for the digit 2.
CallKit automatically plays the corresponding DTMF frequencies for any digits transmitted over a call. The app is responsible for managing the timing and handling of digits as part of fulfilling the action.