IDirectPlay4::SetGroupData
IDirectPlay4 Interface
Associates an application-specific data block with a group ID. Only the computer that created the group can change the remote data associated with it.
Syntax
HRESULT SetGroupData(
DPID idGroup,
LPVOID lpData,
DWORD dwDataSize,
DWORD dwFlags
);
Parameters
- idGroup
- Group ID for which data is being set.
- lpData
- Pointer to the data to be set. Set to NULL to clear any existing group data.
- dwDataSize
- Size of the data buffer. If lpData is NULL and this parameter does not equal zero, the method returns DPERR_INVALIDPARAMS.
- dwFlags
- Flag indicating how the group data is propagated. If this parameter is set to zero, the remote group data will be set and propagated using nonguaranteed messaging.
- DPSET_GUARANTEED
- Propagates the data by using guaranteed messaging (if available). This flag can only be used with DPSET_REMOTE.
- DPSET_LOCAL
- This data is for local use only and will not be propagated.
- DPSET_REMOTE
- This data is for use by all the applications and will be propagated to all the other applications in the session. This flag can only be used on groups owned by the local session.
Return Value
Returns DP_OK if successful, or one of the following error values otherwise:
DPERR_ACCESSDENIED DPERR_CONNECTIONLOST DPERR_INVALIDGROUP DPERR_INVALIDOBJECT DPERR_INVALIDPARAMS
Remarks
DirectPlay can maintain two types of group data: local and remote. Local data is available only to the application on the local computer. Remote data is propagated to all the other applications in the session. A DPSYS_SETPLAYERORGROUPDATA system message will be sent to all players (including the sender) notifying them of the change unless DPSESSION_NODATAMESSAGES is set in the session description. You can safely store pointers to resources in the local data; the local data block is available (in the DPMSG_DESTROYPLAYERORGROUP system message) when the group is being destroyed, so that the application can free those resources. For a list of system messages, see Using System Messages.
This method should not be used for updating real-time information (such as position updates) because of the overhead introduced. IDirectPlay4::Send is much more efficient for updating real-time information. IDirectPlay4::SetGroupData is more appropriate for shared-state information that does not change often and is not time-critical (such as a team color).
See Also
DPMSG_SETPLAYERORGROUPDATA, IDirectPlay4::GetGroupData, IDirectPlay4::Send
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