Detect if headphones are plugged in or not via C#

Question

There is no example how to detect if headphones are plugged in or not via C#.

I assume should be some event for that...

Does make sense to use WMI?

Answer 1

I wouldn't recommend using the COM+ API yourself.

Take a look at the NAudio NuGet package:

Install-Package NAudio

You should be able to enumerate the audio devices with their plugged/unplugged states as follows:

var enumerator = new NAudio.CoreAudioApi.MMDeviceEnumerator();

// Allows you to enumerate rendering devices in certain states
var endpoints = enumerator.EnumerateAudioEndPoints(
    DataFlow.Render,
    DeviceState.Unplugged | DeviceState.Active);
foreach (var endpoint in endpoints)
{
    Console.WriteLine("{0} - {1}", endpoint.DeviceFriendlyName, endpoint.State);
}

// Aswell as hook to the actual event
enumerator.RegisterEndpointNotificationCallback(new NotificationClient());

Where NotificationClient is implemented as follows:

class NotificationClient : NAudio.CoreAudioApi.Interfaces.IMMNotificationClient
{
    void IMMNotificationClient.OnDeviceStateChanged(string deviceId, DeviceState newState)
    {
        Console.WriteLine("OnDeviceStateChanged\n Device Id -->{0} : Device State {1}", deviceId, newState);
    }

    void IMMNotificationClient.OnDeviceAdded(string pwstrDeviceId) { }
    void IMMNotificationClient.OnDeviceRemoved(string deviceId) { }
    void IMMNotificationClient.OnDefaultDeviceChanged(DataFlow flow, Role role, string defaultDeviceId) { }
    void IMMNotificationClient.OnPropertyValueChanged(string pwstrDeviceId, PropertyKey key) { }
}

Should produce a similar result to:

I think the reason why it detects plugging/unplugging twice in the above screenshot is because on Macbook they use one jack for both mic and headphones.