Use Visual Studio 2015 to create.dll and use.dll
In this paper, the implementation of an addition and meet function is taken as an example:
Create a DLL project:
1, File — New — Project — Win32 console application. Give it a name, like myadd. Click OK. Next, select DLL(D) for the application type and click Finish.
>
>
>
>
>
>
>
>
> You can delete it. Create a new one. CPP, name “mydll. CPP”, create a new “mydll.h”
3, write an addition and subtraction function for example; In mydll. CPP, write the following:

#include"stdafx.h"
#include"mydll.h"
int add(int a,int b)
{
    return a+b;
}

int sub(int c,int d)
{
    return c-d;
}

4. Write the following in mydll.h:

#pragma once
_declspec(dllexport)int add(int a, int b);
_declspec(dllexport)int sub(int a, int b);

5. Build — Build the solution. (select Debug X86 mode) and it will be in the project root directory (with.sln directory), under the Debug folder. Generate.dll and.lib files.

> File — New — Project — Win32 Console Application Give it a name like MyDllTest, click OK, Next, Console Application (W), Empty Project (E), Finish;
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Right click, add an existing item, and add mydll.h to the header file.

#include<iostream>
#include "mydll.h"
using namespace std;

int main()
{

    int ad, su;
    ad = add(100, 200);
    su = sub(10, 20);
    cout << "ad: " << ad << endl;
    cout << "su: " << su << endl;
    getchar();
    return 0;
}

5, in the project “resource file” right click, add – existing item; Select the.lib file and click OK.
6, Build, Solution, Run That’s it.

After verification, one of the reasons caused the factors is:
that you declare a function name, and in. H file defines some methods, but not in. CPP implementation inside, this will appear such mistakes.
and the solution can refer to the following:

the above for the nsight eclipse compiler error, as is shown in the display under the compilation instructions. O file is false, do not implement the method can search and in the documents. H file compared to completion.