public static T ActivateInterface <T>(this MMDeviceAPI.IMMDevice device) where T : class
{
var guid = new System.Guid(typeof(T).GetCustomAttribute <System.Runtime.InteropServices.GuidAttribute>(false).Value);
// Normally we're supposed to pass NULL as pActivationParams but C# won't let us pass null to a ref struct argument. Passing an empty PROPVARIANT seems to work fine.
var activationParams = new MMDeviceAPI.tag_inner_PROPVARIANT();
device.Activate(ref guid, (uint)CLSCTX.CLSCTX_ALL, ref activationParams, out var interfacePtr);
object iface;
try
{
iface = System.Runtime.InteropServices.Marshal.GetTypedObjectForIUnknown(interfacePtr, typeof(T));
}
finally
{
System.Runtime.InteropServices.Marshal.Release(interfacePtr);
}
return(iface as T);
}
public static MMDeviceAPI.IPropertyStore GetPropertyStore(this MMDeviceAPI.IMMDevice device, uint sgtmAccess)
{
device.OpenPropertyStore(MMDeviceAPIHelpers.STGM_READ, out var propertyStore);
return(propertyStore);
}
public static string Id(this MMDeviceAPI.IMMDevice device)
{
device.GetId(out var id);
return(id);
}
