The system sends the DBT_QUERYCHANGECONFIG device message to request permission to change the current configuration (dock or undock). Any application can deny this request and cancel the change.
To send the DBT_QUERYCHANGECONFIG device message, the system sends the WM_DEVICECHANGE message with wParam set to DBT_QUERYCHANGECONFIG and lParam set to zero.
Return TRUE to grant permission to change the configuration.
Return BROADCAST_QUERY_DENY to deny permission to change the configuration.
Windows NT: Requires version 5.0 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in dbt.h.
System Messages Overview, System Message Messages, DBT_CONFIGCHANGECANCELED, DBT_CONFIGCHANGED, WM_DEVICECHANGE