Data Channel

Back to INmChannelData Interface

INmChannelData::GetGuid

HRESULT GetGuid(
    [out] GUID *pguid);

Retrieves the globally unique identifier (GUID) used in the creation of the data channel (INmConference::CreateDataChannel).

Returns S_OK if successful, or E_POINTER if the pguid parameter contains an invalid value.

pguid: Pointer to the GUID that identifies a specific data channel.

Back to INmChannelData Interface

INmChannelData::SendData

HRESULT SendData(
    [in] INmMember *pMember,
    [in] ULONG uSize,
    [in] BYTE *pvBuffer,
    [in] ULONG uOptions);

Sends a block of data through the channel to a specified application on the designated member's computer.

Returns one of the following values:

S_OK	Success.
E_POINTER	The pvBuffer pointer is invalid, or uOptions contains an invalid option.
E_NOINTERFACE	The pMember object does not have the required interface.
E_FAIL	The specified data buffer was not sent, the specified member is no longer in the conference, or internal resources are not available.
E_OUTOFMEMORY	Memory could not be allocated to service the request.
S_FALSE	pvBuffer is NULL or uSize is zero.

pMember: Pointer to the INmMember Interface on the Member object to which data will be sent. If this parameter is NULL, the data is sent to all members in the channel.
uSize: Size, in bytes, of the data in the buffer.
pvBuffer: Pointer to a buffer that contains the data to be sent.
uOptions: Flags for data transfer. Reserved for future use. This flag should be set to 0.

DataReceived
DataSent
MemberChanged
NmUI

INmChannelDataNotify Interface

This is an event notification sink interface for the INmChannelData interface. The methods in this interface are called by the Data Channel object when specific events occur.

These event sink methods should be defined and implemented by the client application to respond to notifications from a Data Channel object. For example, the INmChannelDataNotify::DataReceived method is notified when data is received by the local computer. The client application implementation of this method could provide a display to the user informing him or her that the data has been received (including the size of the data, in bytes, which is provided by one of the method's parameters).

INmChannelDataNotify::DataReceived

HRESULT DataReceived(
    [in] INmMember *pMember,
    [in] ULONG uSize,
    [in] byte *pvBuffer,
    [in] ULONG dwFlags);

Receives a notification when data is received by the local computer.

This event sink should always return S_OK to the event source.

pMember

Pointer to the INmMember Interface on the Member object from which the data originated.

uSize

Size, in bytes, of the data in the buffer.

pvBuffer

Pointer to a buffer that contains the data received.

dwFlags

Flag that provides information on the transferred data. This can be one or more of the following:

NM_DF_BROADCAST	Data was broadcast to everyone.
NM_DF_PRIVATE	Data was private.
NM_DF_SEGMENT_BEGIN	Start of data block.
NM_DF_SEGMENT_END	End of data block.

The data buffer is valid only until the DataReceived method returns, at which point it is freed. To access information in the buffer after returning from the DataReceived method, copy the information to another buffer.

INmChannelDataNotify::DataSent

HRESULT DataSent(
    [in] INmMember *pMember,
    [in] ULONG uSize,
    [in] byte *pvBuffer);

Receives a notification after the data is queued up to be sent.

This event sink should always return S_OK to the event source.

pMember: Pointer to the INmMember Interface on the Member object to which the data was sent. If the parameter is NULL, the data was sent to all members in the channel.
uSize: Size, in bytes, of the data in the buffer.
pvBuffer: Pointer to a buffer that contains the data that was sent.

Receipt of this notification indicates that NetMeeting has processed the INmChannelData::SendData request and handed the data off to lower level protocols for transmission. It does not guarantee that the data was transmitted or accepted by any remote computer.

INmChannelDataNotify::MemberChanged

HRESULT MemberChanged(
    [in] NM_MEMBER_NOTIFY uNotify,
    [in] INmMember *pMember);

Receives notification that a member of the Data Channel was added, removed, or updated. This method is inherited from INmChannelNotify.

This event sink should always return S_OK to the event source.

uNotify

Identifier of an event constant during a conference. This can include the following values:

NM_MEMBER_ADDED	A member was added to the conference.
NM_MEMBER_REMOVED	A member was removed from the conference.
NM_MEMBER_UPDATED	Information for a conference member was updated.

pMember

Pointer to the INmMember Interface on the Member object that changed.

INmChannelDataNotify::NmUI

HRESULT NmUI(
    [in] CONFN uNotify);

Receives event notification when a channel change occurs. Only the application in charge (initialized with NM_INIT_CONTROL) of the NetMeeting user interface will receive these notifications. This method is inherited from INmChannelNotify.

This event sink should always return S_OK to the event source.

uNotify: Reserved for future use.