WM_DEVICECHANGE
The WM_DEVICECHANGE device message notifies an application or device driver of a change to the hardware configuration of a device or the computer.
Event = (UINT) wParam;
dwData = (DWORD) lParam;
Parameters
Event
Event type. This parameter can be one of the following values: Value Meaning
DBT_CONFIGCHANGECANCELED A request to change the current configuration (dock or undock) has been canceled.
DBT_CONFIGCHANGED The current configuration has changed, due to a dock or undock.
DBT_DEVICEARRIVAL A device has been inserted and is now available.
DBT_DEVICEQUERYREMOVE Permission is requested to remove a device. Any application can deny this request and cancel the removal.
DBT_DEVICEQUERYREMOVEFAILED A request to remove a device has been canceled.
DBT_DEVICEREMOVECOMPLETE A device has been removed.
DBT_DEVICEREMOVEPENDING A device is about to be removed. Cannot be denied.
DBT_DEVICETYPESPECIFIC A device-specific event has occurred.
DBT_QUERYCHANGECONFIG Permission is requested to change the current configuration (dock or undock).
DBT_USERDEFINED The meaning of this message is user-defined.
dwData
Address of a structure that contains event-specific data. Its meaning depends on the given event.
Return Values
Return TRUE to grant a requested action.
Return BROADCAST_QUERY_DENY to deny a requested action.
Remarks
For devices that offer software-controllable features, such as ejection and locking, the system typically sends a DBT_DEVICEREMOVEPENDING message to let applications and device drivers end their use of the device gracefully.
If the system forcibly removes a device, it may not send a DBT_DEVICEQUERYREMOVE message before doing so.
DBT_CONFIGCHANGECANCELED, DBT_CONFIGCHANGED, DBT_DEVICEARRIVAL, DBT_DEVICEQUERYREMOVE, DBT_DEVICEQUERYREMOVEFAILED, DBT_DEVICEREMOVECOMPLETE, DBT_DEVICEREMOVEPENDING, DBT_DEVICETYPESPECIFIC, DBT_QUERYCHANGECONFIG, DBT_USERDEFINED
QuickInfo
Windows NT: Requires version 4.0 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winuser.h.
See Also
System Messages Overview, System Message Messages