C++项目开发中加载第三方动态库的方法

LoadLibrary

一、语法编辑Syntax（C++）
HMODULE WINAPI LoadLibrary( _In_ LPCTSTR lpFileName);
 
 
二、VB/VC声明
Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long

说明

载入指定的动态链接库，并将它映射到当前进程使用的地址空间。一旦载入，即可访问库内保存的资源

返回值

Long，成功则返回库模块的句柄，零表示失败。会设置GetLastError

参数 类型及说明

lpLibFileName String，指定要载入的动态链接库的名称。采用与CreateProcess函数的lpCommandLine参数指定的同样的搜索顺序

注解

一旦不需要，用FreeLibrary函数释放DLL
 

三、VB6实例
Create a new project and add this code to Form1

Private Declare Function FreeLibrary Lib "kernel32" (ByVal hLibModule As Long) As Long

Private Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long

Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, ByVal lpProcName As String) As Long

Private Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Any, ByVal wParam As Any, ByVal lParam As Any) As Long

Private Sub Form_Load()

On Error Resume Next

'KPD-Team 1999

'We're going to call an API-function, without declaring it!

Dim lb As Long, pa As Long

'map 'user32' into the address space of the calling process.

Lb = LoadLibrary("user32")

'retrieve the address of 'SetWindowTextA'

pa = GetProcAddress(lb, "SetWindowTextA")

'Call the SetWindowTextA-function

CallWindowProc pa, Me.hWnd, "Hello !", ByVal 0&, ByVal 0&

'unmap the library's address

FreeLibrary lb

End Sub
 
四、相应FreeLibrary用法：
FreeLibrary(LoadLibrary时所创建的句柄)

（改编自百度百科：http://baike.baidu.com/view/1286902.htm）