Detecting if headphones are plugged into iPhone

Question

Does anyone know if you can detect if headphones are plugged into the iPhone, and if they aren\'t - disable sound from your application.

I think I could manage disab

Answer 1

To perform a one-off check to determine if headphones are plugged in (rather than setting a callback when they're unplugged) I found the following works in iOS5 and above:

- (BOOL) isAudioJackPlugged
{

// initialise the audio session - this should only be done once - so move this line to your AppDelegate
AudioSessionInitialize(NULL, NULL, NULL, NULL);
UInt32 routeSize;

// oddly, without calling this method caused an error.
AudioSessionGetPropertySize(kAudioSessionProperty_AudioRouteDescription, &routeSize);
CFDictionaryRef desc; // this is the dictionary to contain descriptions

// make the call to get the audio description and populate the desc dictionary
AudioSessionGetProperty (kAudioSessionProperty_AudioRouteDescription, &routeSize, &desc);

// the dictionary contains 2 keys, for input and output. Get output array
CFArrayRef outputs = CFDictionaryGetValue(desc, kAudioSession_AudioRouteKey_Outputs);

// the output array contains 1 element - a dictionary
CFDictionaryRef dict = CFArrayGetValueAtIndex(outputs, 0);

// get the output description from the dictionary
CFStringRef output = CFDictionaryGetValue(dict, kAudioSession_AudioRouteKey_Type);

/**
 These are the possible output types:
 kAudioSessionOutputRoute_LineOut
 kAudioSessionOutputRoute_Headphones
 kAudioSessionOutputRoute_BluetoothHFP
 kAudioSessionOutputRoute_BluetoothA2DP
 kAudioSessionOutputRoute_BuiltInReceiver
 kAudioSessionOutputRoute_BuiltInSpeaker
 kAudioSessionOutputRoute_USBAudio
 kAudioSessionOutputRoute_HDMI
 kAudioSessionOutputRoute_AirPlay
 */

return CFStringCompare(output, kAudioSessionOutputRoute_Headphones, 0) == kCFCompareEqualTo;
}

For those keeping score at home, that's a string in a dictionary in an array in a dictionary.