C++ dll实例
动态链接库的制作:
Windows桌面向导-应用程序类型:动态链接库(.dll) 空项目 MyDynamicLib
头文件声明函数时,在前面加上 extern "C" __declspec(dllexport)
1 //MyDynamicLib.h
2 #pragma once
3 extern "C" __declspec(dllexport) int GetMaxCommDiv(int a, int b);
4 extern "C" __declspec(dllexport) int GetMinCommMul(int a, int b);
1 //MyDynamicLib.cpp
2 #include "MyDynamicLib.h"
3
4 int GetMaxCommDiv(int a, int b)
5 {
6 int x = 1;
7 int ires;
8 if (a < b)
9 return 0;
10 if (b == 0)
11 return 0;
12 while (x != 0)
13 {
14 x = a % b;
15 a = b;
16 ires = b;
17 b = x;
18 }
19 return ires;
20 }
21
22 int GetMinCommMul(int a, int b)
23 {
24 int x = 1;
25 int ires;
26 int m, n;
27 m = a; n = b;
28 if (a < b)
29 return 0;
30 if (a == 0)
31 return 0;
32 if (b == 0)
33 return 0;
34 while (x != 0)
35 {
36 x = a % b;
37 a = b;
38 ires = b;
39 b = x;
40 }
41 ires = (m * n) / ires;
42 return ires;
43 }
DLL文件的使用:
将.h .dll .lib三个文件都复制到工程目录,不需要添加到工程里,就可以直接使用.
1 #include <iostream> 2 #include "MyDynamicLib.h" 3 #pragma comment(lib, "MyDynamicLib") 4 5 int main() 6 { 7 int m = 360, n = 100; 8 std::cout << "MaxCommDiv: " << GetMaxCommDiv(m, n) << std::endl; 9 std::cout << "MinCommMul: " << GetMinCommMul(m, n) << std::endl; 10 return 0; 11 }
动态加载动态链接库:
将.h .dll .lib三个文件都复制到工程目录,不需要添加到工程里,就可以直接使用.
1 #include <iostream>
2 #include <windows.h>
3 #include "MyDynamicLib.h"
4
5
6 int main()
7 {
8 int m = 360, n = 100;
9 typedef int(__cdecl* MyFunc)(int, int);
10 HMODULE hModule = ::LoadLibrary("MyDynamicLib.dll");
11 if (hModule == NULL)
12 return 0;
13 MyFunc GetValue = (MyFunc)GetProcAddress(hModule, "GetMaxCommDiv");
14
15 std::cout << "MaxCommDiv: " << GetValue(m, n) << std::endl;
16
17 GetValue = (MyFunc)GetProcAddress(hModule, "GetMinCommMul");
18 std::cout << "MinCommMul: " << GetValue(m, n) << std::endl;
19
20 FreeLibrary(hModule);
21 return 0;
22 }
