Prototype and description of the function closentvbinaryfile()

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

closentvbinaryfile()
Closes the NTv2 grid data binary file and frees the NTv2 instance.

Prototype of the DLL function in C++ syntax (attend lower case!):
extern "C" __declspec(dllimport) unsigned long __stdcall closentvbinaryfile(
     void);

Prototype of the DLL function in Visual Objects syntax:
_DLL function closentvbinaryfile();
as logic pascal:geodll32.closentvbinaryfile  // 4 Byte


The function closes an NTv2 grid data binary file and releases the
corresponding NTv2 instance.

With the call of the functions setntvbinaryfile(), setntvbinautofile()
and setntvbinautodir() an NTv2 instance is created in GeoDLL, in which with
the first NTv2-based coordinate transformation an NTv2 grid data binary file
will be opened. The NTv2 instance remains active and the associated NTv2
file remains open until one of the following events occurs:
1. The program using the GeoDLL is closed.
2. The program using the GeoDLL releases the GeoDLL.
3. A new NTv2-instance is created with the above mentioned functions.
4. The function closentvbinaryfile() is called.

This means that the closentvbinaryfile() function must only be called if all
NTv2-based coordinate transformations are finished and external access to the
NTv2 binary file should be possible during further program execution.


The parameters are passed and/or returned as follows:
returnVal     In case of an error the function returns FALSE, otherwise TRUE.


Unlocking:
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.