We help IT Professionals succeed at work.

MCI: how to determine CDaudio drive door status

mauromol
mauromol asked
on
379 Views
Last Modified: 2013-12-03
I know MCI CDAudio device handling quite well, but I still don't know how to determine wether the CD-ROM drive door is open or closed, in order to distinguish when I have to call MCI_Set_Door_Closed instead of MCI_Set_Door_Open.
Comment
Watch Question

Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION
MCI_STATUS_PARMS status;
status.dwitem = MCI_STATUS_MODE;

mciSendCommand(deviceid,MCI_STATUS,MCI_WAIT | MCI_STATUS_ITEM,*status);

if(status.dwReturn == MCI_MODE_OPEN
    The door is open
else
    The door is closed


I do this for my cd player to determine whether my eject button should send a MCI_SET_DOOR_CLOSED or _OPEN command.

Author

Commented:
To overworked: this does not work, sorry. MCI_Mode_Open is returned both when the door is open and when the door is closed but the drive is empty.

Author

Commented:
To chensu: I had a look to the link you gave me: thank you!
I would have only a question: Microsoft says that the Device Type should be a dbt_DevTyp_Volume, but when I intercept wm_DeviceChange, dbch_DeviceType seems to be set to dbt_DevTyp_OEM. Why?
Delphi doesn't define dbt constants: I use explicit numbers for that (dbt_DeviceArrival = $8000, where $ means hex number; dbt_DeviceRemoveComplete = $8004; dbt_DevTyp_Volume = $2), but both dbt_DeviceArrival and dbt_DeviceRemoveComplete return $0 (that should be dbt_DevTyp_OEM, shouldn't it?) instead of $2. Maybe you know where the problem is?

Commented:
On my computer, dbch_devicetype is DBT_DEVTYP_VOLUME. Check it carefully. And, try it on other computers.

Author

Commented:
Ok, I got it to work, thank you!
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a sample view!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.