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

Minimum supported client
Windows XP
Minimum supported server
Windows Server 2003
Header
Dbt.h

See also

Device Events

Device Management Events

DEV_BROADCAST_HDR

WM_DEVICECHANGE