Prototype and description of the function getntvrefstatus()

(Function of the unlock requiring group "NTv2 Transformations")


Determining whether a Reference System belongs to a NTv2 grid file.

Prototype of the DLL function in C++ syntax (attend lower case!):
extern "C" __declspec(dllimport) unsigned long __stdcall getntvrefstatus(
     unsigned short wRefSys,
     unsigned long *wRefNtvB);

Prototype of the DLL function in Visual Objects syntax:
_DLL function getntvrefstatus(;
     wRefSys as word,;                     // 2 Byte
     lStatus ref logic);                   // 4 Byte
as logic pascal:geodll32.getntvrefstatus   // 4 Byte

The function tests whether the Reference System in wRefSys belongs to a
NTv2 grid file and returns the result in the logical variable lStatus.

The parameters are passed and/or returned as follows:
wRefSys     Geodetic Reference System, which is to be testet on the
            membership of a NTv2 grid file. The available reference
            systems are specified in the list "Coordinate and reference

lStatus     Status "NTv2 Reference System". The status is returned by
(ref)       reference.
TRUE        The Reference System belongs to a NTv2 grid file.
FALSE       The Reference System belongs not to a NTv2 grid file.

returnVal   In case of an error the function returns FALSE, otherwise TRUE.

This function is a component of the unlock requiring function group
"NTv2 Transformations". It is unlocked for unrestricted use together with the
other functions of the group by passing the unlock parameters, acquired
from the software distribution company, trough the function setunlockcode().
Without unlocking only a few function calls for test purposes (shareware
principle) are possible. It should be noted that in addition the function
group "Coordinate Transformations" must be unlocked.