WM_DEVICECHANGE sets wParam to DBT_DEVNODES_CHANGED to update list (tree?) nodes.
No other info is available then. I have not retrieved any device list, so it is useless for me.
To receive DBT_DEVICEARRIVAL it is necessary to first use RegisterDeviceNotification.
At this point no other help is required.
I need some help / hints with implementing WM_DEVICECHANGE in MFC Document /View setup.
I have managed to intercept the WM_DEVICECHANGE in CmainFrame message map and process it .
The problem m is that the wParam is nowhere near the 0x8xxx, but it is plain “7” and the lParam is 0.
I went thru the Dbt.h and cannot figure out what is the wParam = 7 telling me.
Here is the code snippet and if it is not formatted to you liking – I am sorry , but I write my stuff in OpenOffice and than copy it to CodeProject so it cannot be formatted properly.
<b>I just need some troubleshooting pointer / suggestion how to analyze these mysterious parameters. </b>
Maybe CmainFRame is not the place to start, but I got same parameters values when I used Cdialog message map directly.
JUst found this info, so the additional question is - is CMainFrame "top window" and if not will RegisterDeviceNotification solve this ? I shall try it next.
The DBT_DEVICEARRIVAL and DBT_DEVICEREMOVECOMPLETE events are automatically broadcast to all top-level windows for port devices. Therefore, it is not necessary to call RegisterDeviceNotification for ports, and the function fails if the dbch_devicetype member is DBT_DEVTYP_PORT.
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Thank you, obviously I have not look all the way to the end of the page!
However, what the dickens is " ring3 people" note talking about?
So when "new node is detected / chaged" is not same as
DBT_DEVICEARRIVAL A device has been inserted and is now available.
Mr MS - I am not sure this note is in English!
and to get the device more work is necessary???
I am not sure I can figure that out, getting tired of this USB mess.
* Message = WM_DEVICECHANGE
* wParam = DBT_DEVNODES_CHANGED
* lParam = 0
* send when configmg finished a process tree batch. Some devnodes
* may have been added or removed. This is used by ring3 people which
* need to be refreshed whenever any devnode changed occur (like
* device manager). People specific to certain devices should use
* DBT_DEVICE* instead.
#define DBT_DEVNODES_CHANGED 0x0007