_DEV_BROADCAST_USERDEFINED

The _DEV_BROADCAST_USERDEFINED structure contains the user-defined message and optional data associated with the DBT_USERDEFINED device message.

struct _DEV_BROADCAST_USERDEFINED { 
    struct _DEV_BROADCAST_HDR dbud_dbh; 
    char  dbud_szName[1];           // ASCIIZ name  
//    BYTE  dbud_rgbUserDefined[];  // Optional user-defined contents  
}; 
 

Members

dbud_dbh

Information about the device affected by a WM_DEVICECHANGE message as specified by the DEV_BROADCAST_HDR structure. Because the _DEV_BROADCAST_USERDEFINED structure is variable length, dbud_dbh.dbch_size must be the size in bytes of the entire structure, including the variable length part.

dbud_szName

A case-sensitive, null-terminated string that names the message. The name must consist of the vendor name, a backslash, followed by arbitrary user-defined null-terminated text. For example:

"WidgetWare\QueryScannerShutdown" 

or

"WidgetWare\Video Q39S\AdapterReady"
 

dbud_rgbUserDefined

Optional user-defined information.

Because this structure contains variable length fields, use this structure tag as a template for creating a pointer to a user-defined structure. Note that the structure must not contain pointers. For example:

#define NAME_LENGTH 32 
#define USER_LENGTH 50 
 
typedef struct tagWIDGET_WARE_DEV_BROADCAST_USERDEFINED
{
    struct _DEV_BROADCAST_HDR DBHeader; 
    char  szName[NAME_LENGTH]
    BYTE  UserDefined[USER_LENGTH]; 
} WIDGET_WARE_DEV_BROADCAST_USERDEFINED;
 

QuickInfo

  Windows NT: Requires version 5.0 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in dbt.h.

See Also

System Messages Overview, System Message Structures, DBT_USERDEFINED, DEV_BROADCAST_HDR, WM_DEVICECHANGE