DBT_DEVICEARRIVAL event

The system broadcasts the DBT_DEVICEARRIVAL device event when a device or piece of media has been inserted and becomes available.

To broadcast this device event, the system uses the WM_DEVICECHANGE message with wParam set to DBT_DEVICEARRIVAL and lParam set as described following.

LRESULT CALLBACK WindowProc(
  HWND hwnd,       // handle to window
  UINT uMsg,       // WM_DEVICECHANGE
  WPARAM wParam,   // device-change event
  LPARAM lParam    // event-specific data
);

hwnd

A handle to a window.

uMsg

The WM_DEVICECHANGE message identifier.

wParam

Set to DBT_DEVICEARRIVAL.

lParam

A pointer to a structure identifying the device inserted. The structure consists of an event-independent header, followed by event-dependent members that describe the device. To use this structure, treat the structure as a DEV_BROADCAST_HDR structure, then check its dbch_devicetype member to determine the device type.

Return TRUE.

If media is being inserted, the type of device arriving is a volume (the dbch_devicetype member is DBT_DEVTYP_VOLUME) and the change effects the media (the dbcv_flags member is DBTF_MEDIA).

For an example, see Detecting Media Insertion or Removal.

Device Events

Device Management Events

DEV_BROADCAST_HDR

WM_DEVICECHANGE