i think i have a lead!

Printable View

Jul 11th, 2003, 11:23 AM
seec77

i think i have a lead!

i think i have a lead to a question that has been asked a lot of times, but as far as i know (please correct me if im wrong) has never been answered...
the question is, how can a program be notified the minute a cd is inserted into the tray....
this is my lead....
it's obvious it has something to do with mci (duh, that's how you can open a tray through a program) and i was looking the other day at api-guide on "mciSendString"....
i noticed the last parameter, "hwndCallback"....
here is the description: "Handle of a callback window if the 'notify' flag was specified in the command string." !
this means, our program can be notified somehow if we do a certain mci command and add "notify" to it...
it might just work, please help me solve this everlasting question!
Jul 11th, 2003, 11:43 AM
seec77

and yet another lead!
when the drive is closed, we can send an mci command to the drive to close itself, and use the "notify" flag so when it's done it'll notify us.... now we just have to learn how to use that notify flag with the hwnd!
please help me!
Jul 11th, 2003, 12:07 PM
crptcblade
Quote:

Originally posted by seec77
now we just have to learn how to use that notify flag with the hwnd!

In the help docs, it says the the hWnd will receive a MM_MCINOTIFY message when the operation is complete.
VB Code:
```
Private Const MM_MCINOTIFY = &H3B9
```
Its subclassing time!
Jul 17th, 2003, 05:03 PM
seec77

sorry for not replying ctrcpblade, i was in camp in the middle of nowhere sleeping under the stars and building everything i needed for five days.... can't think of any better way to spend my time.... ;)
anyway, yep, that really helps! ill try, please people help us, this is a question that bugs many people i know.....
Jul 17th, 2003, 06:12 PM
Shawn N

I'll see if I can help you out when I get home from work in about 5 hours. :)
Jul 17th, 2003, 06:39 PM
manavo11

What would we be subclassing for this? The form?
Jul 17th, 2003, 07:17 PM
Shawn N

Quote:

Originally posted by manavo11
What would we be subclassing for this? The form?

Yeap.
Jul 17th, 2003, 07:49 PM
manavo11

Quote:

Originally posted by Shawn N
Yeap.

Looks interesting. I will probably look into it...
Jul 18th, 2003, 03:51 AM
Shawn N

I got my code detecting when a cd has been inserted or removed. I'll post the coding when I can figure out how to detect what drive Windows is talking about.
Jul 18th, 2003, 02:49 PM
seec77

why not post the code and we'll help you detect it?
Jul 18th, 2003, 03:28 PM
Eras3r

why would you be subclassing anything? all you need is a callback function. ... thats not subclassing.
Jul 18th, 2003, 03:31 PM
seec77

in mci that's not how it works, when you put a notify tag in an mcisendmessage command, it sends an mm_mcinotify (i think) message, and that's why we have to subclass....
btw, i don't think this approach is correct, i have tried closing the cd with a notify, and it started it, and my cd being closed, it immediately notified me....
Jul 19th, 2003, 12:01 AM
Shawn N

1 Attachment(s)

Quote:

Originally posted by seec77
why not post the code and we'll help you detect it?

Mmk - but the coding is not complete and kind of ugly right now.
Jul 19th, 2003, 02:58 AM
seec77

that's really weird, it doesn't get any wm_devicechanged message though the dbl click works fine, though now i know how it works, ill try to get it to work myself....
Jul 19th, 2003, 03:12 AM
seec77

i think i have found a better way to do what we wan't to do....
check this out: http://www.pscode.com/vb/scripts/Sho...23405&lngWId=1
it also does media added by get a registering an sh notification message and reading a SHCNE_MEDIAINSERTED and a SHCNE_MEDIAREMOVED...
Jul 19th, 2003, 09:02 AM
Shawn N

Quote:

Originally posted by seec77
that's really weird, it doesn't get any wm_devicechanged message though the dbl click works fine

Pretty strange. I wonder if it's just your computer. What OS is running?
Sep 23rd, 2003, 04:43 PM
manavo11

1 Attachment(s)

Well I found this that seems to do it :)

Error:
Project library not found (something like that)

VB Code:

[COLOR=deeppink]Sub ProcessDeviceChange(wParam As Long, lParam As Long)[/COLOR] 
    Dim DBHdr As DEV_BROADCAST_HDR
    Dim DBVol As DEV_BROADCAST_VOLUME
    CopyMemory DBHdr, ByVal lParam, LenB(DBHdr)
    Select Case wParam
        Case DBT_DEVICEARRIVAL
            'See if a CD-ROM or DVD was inserted into a drive.
            If DBHdr.dbch_devicetype = DBT_DEVTYP_VOLUME Then
                CopyMemory DBVol, ByVal lParam, LenB(DBVol)
                If (DBVol.dbcv_flags And DBTF_MEDIA) = DBTF_MEDIA Then
                    frmMain.lstChanged.AddItem "New media inserted in drive " + Chr$(FirstDriveFromMask(DBVol.dbcv_unitmask))
                End If
            End If
        Case DBT_DEVICEREMOVECOMPLETE
            'See if a CD-ROM or DVD was removed from a drive.
            If DBHdr.dbch_devicetype = DBT_DEVTYP_VOLUME Then
                CopyMemory DBVol, ByVal lParam, LenB(DBVol)
                If (DBVol.dbcv_flags And DBTF_MEDIA) = DBTF_MEDIA Then
                    frmMain.lstChanged.AddItem "Media removed from drive " + Chr$(FirstDriveFromMask(DBVol.dbcv_unitmask))
                End If
            End If
    End Select
End Sub

WinXPPro / VB6

EDIT:
Story as follows:
The CDROM was empty. Ran program and inserted media, error as above. I closed program, and the media was still in drive. I ran the program, opened CDROM and took out media, and it worked. I closed program, and inserted then took out and it now works...anyone know why?

thanks,
alacritous

Sep 23rd, 2003, 05:18 PM
manavo11

Where does that error occur? What does it highlight?
Sep 23rd, 2003, 05:21 PM
alacritous

Highlights the pink, when I inserted the media, read my EDIT though, before you jump to conclusions.. ill be on aim if you want alacritous8 but I'll be eatting for a lil...

thanks