DBT_DEVNODES_CHANGED event
The system broadcasts the DBT_DEVNODES_CHANGED device event when a device has been added to or removed from the system. Applications that maintain lists of devices in the system should refresh their lists.
To broadcast this device event, the system uses the WM_DEVICECHANGE message with wParam set to DBT_DEVNODES_CHANGED and lParam set to zero.
LRESULT CALLBACK WindowProc(
HWND hwnd, // handle to window
UINT uMsg, // WM_DEVICECHANGE
WPARAM wParam, // device-change event
LPARAM lParam // event-specific data
);
Parameters
-
hwnd
-
A handle to a window.
-
uMsg
-
The WM_DEVICECHANGE message identifier.
-
wParam
-
Set to DBT_DEVNODES_CHANGED.
-
lParam
-
Set to zero.
Return value
Return TRUE.
Remarks
There is no additional information about which device has been added to or removed from the system. Applications that require more information should register for device notification using the RegisterDeviceNotification function.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows XP |
| Minimum supported server |
Windows Server 2003 |
| Header |
|