phoneNegotiateExtVersion  129YGLD 

The phoneNegotiateExtVersion function allows an application to negotiate an extension version to use with the specified phone device. This operation need not be called if the application does not support extensions.

LONG phoneNegotiateExtVersion(

    HPHONEAPP hPhoneApp,

 

    DWORD dwDeviceID,

 

    DWORD dwAPIVersion,

 

    DWORD dwExtLowVersion,

 

    DWORD dwExtHighVersion,

 

    LPDWORD lpdwExtVersion

 

   );

 

 

Parameters

hPhoneApp

The handle to the application's registration with TAPI.

dwDeviceID

The phone device to be queried.

dwAPIVersion

The API version number that was negotiated for the specified phone device using phoneNegotiateAPIVersionEEC_HG.

dwExtLowVersion

The least recent extension version of the Extension ID returned by phoneNegotiateAPIVersion that the application is compliant with. The high-order word is the major version number; the low-order word is the minor version number.

dwExtHighVersion

The most recent extension version of the Extension ID returned by phoneNegotiateAPIVersion that the application is compliant with. The high-order word is the major version number; the low-order word is the minor version number.

lpdwExtVersion

A pointer to a DWORD-sized location that contains the extension version number that was negotiated. If negotiation is successful, this number will be in the range dwExtLowVersion and dwExtHighVersion.

 

Return Values

Returns zero if the request is successful or a negative error number if an error has occurred. Possible return values are:

PHONEERR_INVALAPPHANDLE, PHONEERR_OPERATIONFAILED, PHONEERR_BADDEVICEID, PHONEERR_OPERATIONUNAVAIL, PHONEERR_NODRIVER, PHONEERR_NOMEM, PHONEERR_INCOMPATIBLEAPIVERSION, PHONEERR_RESOURCEUNAVAIL, PHONEERR_INCOMPATIBLEEXTVERSION, PHONEERR_UNINITIALIZED, PHONEERR_INVALPOINTER, PHONEERR_NODEVICE.

Remarks

The function phoneNegotiateAPIVersion is used to negotiate the API version number to use. It returns the extension ID supported by the phone device, or zeros if no extensions are provided.

If the application wants to use the extensions defined by the returned Extension ID, it must call phoneNegotiateExtVersion to negotiate the extension version to use.

Use phoneInitializeEx to determine the number of phone devices present in the system. The device ID specified by dwDeviceID varies from zero to one less than the number of phone devices present.

The extension version number negotiated is that under which the application and service provider must both operate. If version ranges do not overlap, the application and service-provider versions are incompatible and an error is returned.

See Also

phoneInitializeEx, phoneNegotiateAPIVersion