DEV_BROADCAST_HDR structure (dbt.h)
Serves as a standard header for information related to a device event reported through the WM_DEVICECHANGE message.
The members of the DEV_BROADCAST_HDR structure are contained in each device management structure. To determine which structure you have received through WM_DEVICECHANGE, treat the structure as a DEV_BROADCAST_HDR structure and check its dbch_devicetype member.
Syntax
typedef struct _DEV_BROADCAST_HDR {
DWORD dbch_size;
DWORD dbch_devicetype;
DWORD dbch_reserved;
} DEV_BROADCAST_HDR;
Members
dbch_size
The size of this structure, in bytes.
If this is a user-defined event, this member must be the size of this header, plus the size of the variable-length data in the _DEV_BROADCAST_USERDEFINED structure.
dbch_devicetype
The device type, which determines the event-specific information that follows the first three members. This member can be one of the following values.
| Value | Meaning |
|---|---|
|
Class of devices. This structure is a DEV_BROADCAST_DEVICEINTERFACE structure. |
|
File system handle. This structure is a DEV_BROADCAST_HANDLE structure. |
|
OEM- or IHV-defined device type. This structure is a DEV_BROADCAST_OEM structure. |
|
Port device (serial or parallel). This structure is a DEV_BROADCAST_PORT structure. |
|
Logical volume. This structure is a DEV_BROADCAST_VOLUME structure. |
dbch_reserved
Reserved; do not use.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows XP |
| Minimum supported server | Windows Server 2003 |
| Header | dbt.h |