_DEV_BROADCAST_USERDEFINED

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

typedef struct _DEV_BROADCAST_USERDEFINED { 
  struct _DEV_BROADCAST_HDR dbud_dbh; 
  char  dbud_szName[1];           // name string 
//  BYTE  dbud_rgbUserDefined[];    // optional user-defined data  
}; 

Members

dbud_dbh

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

dbud_szName

A case-sensitive, null-terminated string that names the message. The string 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.

Remarks

Because this structure contains variable length fields, use it as a template for creating a pointer to a user-defined structure. Note that the structure must not contain pointers. The following example shows such a user-defined structure.

#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;

Requirements

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Dbt.h.

See Also

Device Management Overview, Device Management Structures, DBT_USERDEFINED, DEV_BROADCAST_HDR, WM_DEVICECHANGE