Use the lineGetUSSD function to read an Unstructured Supplementary Service Data (USSD) message.

LONG WINAPI lineGetUSSD(
  HLINE hLine,
  DWORD dwID,
  LPBYTE lpbUSSD,
  DWORD dwUSSDSize,
  LPDWORD lpdwFlags
);

Parameters

hLine

The line device handle. The line device handle must have been previously obtained by a call to lineOpen with the proper TAPI device ID specified and a device-specific extension version successfully negotiated with lineNegotiateExtVersion. For more information about lineNegotiateExtVersion and lineOpen, see the TAPI Functions API Reference topics on MSDN.

dwID

Indicates which USSD message to retrieve. The identifier is specified in the LINE_DEVSPECIFIC or LINE_USSD message that the application received.

lpbUSSD

Points to a buffer to which the USSD message will be copied.

dwUSSDSize

Indicates the size in bytes of the lpszUSSD buffer.

lpdwFlags

Points to a DWORD indicating special flags pertaining to this network-originated USSD message. Possible values are listed in the following table.

Value	Description
LINEUSSDFLAG_ACTIONREQUIRED	Network needs more USSD information sent back.
LINEUSSDFLAG_ACTIONNOTNEEDED	Network does not need more USSD info.
LINEUSSDFLAG_TERMINATED	Network has terminated USSD session.
LINEUSSDFLAG_OTHERCLIENTRESPONDED	Network has terminated the USSD session because another client responded.
LINEUSSDFLAG_UNSUPPORTED	Network does not support USSD.
LINEUSSDFLAG_TIMEOUT	USSD session timed out.
LINEUSSDFLAG_ENDSESSION	Network is terminating USSD session.

Return Values

Returns zero if the function completes successfully, or a negative error number if an error occurs. The following are possible return values:

LINEERR_RESOURCEUNAVAIL
LINEERR_INVALLINEHANDLE
LINEERR_STRUCTURETOOSMALL
LINEERR_INVALPOINTER
LINEERR_UNINITIALIZED
LINEERR_NOMEM
LINEERR_OPERATIONUNAVAIL
LINEERR_OPERATIONFAILED

Remarks

This is a privileged function.

This function is synchronous. No LINE_REPLY message is sent. Not implemented for CDMA.

Requirements

Pocket PC: Pocket PC 2002 and later.
Smartphone: Smartphone 2002 and later.
OS Versions: Windows CE 3.0 and later.
Header: Extapi.h.
Library: Cellcore.lib.

See Also

Extended TAPI Functions

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