How to add audio device action sheet to your iOS app

Stephen
2 min readNov 5, 2019

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audio devices action sheet from Callkit

When developing an app with music, video, call functions, it always comes up this requirement:

How to select a desired audio device

Like the above image, it’s from CallKit where you can select the desired audio output from this action sheet.

First, we have to understand how many audio routes and how they switch. We will be based on developing a phone call app because it can involve both audio input and output.

iPhone: the iPhone handset is default route for a call.

Speaker: the speaker is the default output audio for like music, video, ring tone.

Bluetooth: whenever a bluetooth device connected, the bluetooth device will become the default audio route.

Headphones: whenever any headphones plugged in, it becomes the default audio route even there is also bluetooth device. And it overwrites the handset(iPhone) option, which means you cannot change to the handset(iPhone).

Headphones take the priority over handset

After figuring out the desired devices list and rule, we can conclude the design:

If there is no bluetooth device connected, we don’t need to provide the action sheet. Instead it can just toggle between handset(or headset) and speaker.

If there is any bluetooth devices connected, the action sheet will be

  1. Handset/Headset
  2. Speaker
  3. Bluetooth devices

How to get the desired AVAudioSessionPort

You can find the available input ports from AVAudioSession.sharedInstance().availableInputs

and find current routes(output) from

AVAudioSession.sharedInstance().currentRoute

And the below are the possible ports:

Headset mic: AVAudioSessionPortBuiltInMic

Headset output: AVAudioSessionPortBuiltInReceiver

Handset mic: AVAudioSessionPortHeadsetMic

Handset output: AVAudioSessionPortHeadphones

Speaker: AVAudioSessionPortBuiltInSpeaker

Bluetooth mic: AVAudioSessionPortBluetoothHFP

Bluetooth output: AVAudioSessionPortBluetoothHFP, AVAudioSessionPortBluetoothA2DP, AVAudioSessionPortBluetoothLE

How to bring up an action sheet dialog

Simply use UIAlertController with preferredStyle as .actionSheet

audio device action sheet

Alright! That’s it. Feel free to share your feedback or suggestion.

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