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Other programming languages, Other programming languages -4 – National Instruments NI-DNET User Manual

Page 23

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Chapter 3

Developing Your Application

NI-DNET User Manual

3-4

ni.com

For C applications (files with

.c

extension), include the header file by

adding a

#include

to the beginning of your code, like this:

#include "nidnet.h"

For C++ applications (files with

.cpp

extension), define

_cplusplus

before including the header, such as:

#define _cplusplus

#include "nidnet.h"

The

_cplusplus

define enables the transition from C++ to the C language

NI-DNET functions.

The reference for each NI-DNET function is provided in the NI-DNET
Programmer Reference Manual
, which you can open from Start»All
Programs»National Instruments»NI-DNET
.

You can find examples for Visual C++ in the

examples

subfolder of the

Borland C

folder. Each example is in a separate folder. A

.c

file with the

same name as the example contains a description the example in comments
at the top of the code.

Other Programming Languages

You can directly access NI-DNET from any programming environment
that allows you to request addresses of functions that a dynamic link library
(DLL) exports. The functions used to access a DLL in this manner are
provided by the Microsoft Win32 functions of Windows. Using these
Microsoft Win32 functions to access a DLL is often referred to as direct
entry. To use direct entry with NI-DNET, complete the following steps:

1.

Load the NI-DNET DLL,

nican.dll

.

The following C language code fragment illustrates how to call the
Win32

LoadLibrary

function and check for an error.

#include

#include "nidnet.h"

HINSTANCE NidnetLib = NULL;

NidnetLib=LoadLibrary("nican.dll");

if (NidnetLib == NULL) {

return FALSE; /*Error*/

}