Windows Mobile和Wince(Windows Embedded CE)下封装Native DLL进一步探讨

电玩女神 2022-02-02 07:01 210阅读 0赞

之前写过一篇关于Windows Mobile和Wince(Windows Embedded CE)下封装Native DLL的文章，原文如下：

[Windows Mobile和Wince(Windows Embedded CE)下如何封装Native DLL提供给.NET Compact Framework进行调用][Windows Mobile_Wince_Windows Embedded CE_Native DLL_.NET Compact Framework]

原文主要针对如何封装的Native DLL提供给.NET Compact Framework的程序来调用。但是如果按照原文的方法进行封装，使用Native C++调用该封装DLL会有一些麻烦，需要动态加载该DLL，关于动态加载，我之前也写过一篇文章，原文如下：

[如何在Windows Mobile下使用Native C++动态加载DLL][Windows Mobile_Native C_DLL]

动态加载有其好处，但是如果封装的DLL和调用方都是内部的程序，使用初始化时候加载（也叫做静态加载），在开发时会更加方便和简单。下面讲述如何封装DLL为调用方提供静态加载服务。

### 1.建立输出定义头文件 ###

// The following ifdef block is the standard way of creating macros which make exporting 
    
    // from a DLL simpler. All files within this DLL are compiled with the MY32FEETWIDCOMM_EXPORTS
    
    // symbol defined on the command line. this symbol should not be defined on any project
    
    // that uses this DLL. This way any other project whose source files include this file see 
    
    // MY32FEETWIDCOMM_API functions as being imported from a DLL, whereas this DLL sees symbols
    
    // defined with this macro as being exported.
    #ifdef MY32FEETWIDCOMM_EXPORTS
    #define MY32FEETWIDCOMM_API __declspec(dllexport)
    #else
    #define MY32FEETWIDCOMM_API __declspec(dllimport)
    #endif
    
    // This class is exported from the 32feetWidcommWM.dll
    class MY32FEETWIDCOMMWM_API CMy32feetWidcommWM {
       
    public:
    
    CMy32feetWidcommWM(void);
    // TODO: add your methods here.
    };
    
    extern MY32FEETWIDCOMMWM_API int nMy32feetWidcommWM;
    
    
    MY32FEETWIDCOMMWM_API int fnMy32feetWidcommWM(void);

调用方需要\#include该头文件。

### 2.实现头文件提供的接口 ###

// 32feetWidcommWM.cpp : Defines the entry point for the DLL application.
    
    //
    
    #include "stdafx.h"
    #include "32feetWidcommWM.h"
    #include <windows.h>
    #include <commctrl.h>
    
    BOOL APIENTRY DllMain( HANDLE hModule, 
    
    DWORD  ul_reason_for_call, 
    
    LPVOID lpReserved
    
    )
    
    {
       
    switch (ul_reason_for_call)
    
    {
       
    case DLL_PROCESS_ATTACH:
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
    break;
    
    }
    return TRUE;
    
    }
    
    // This is an example of an exported variable
    MY32FEETWIDCOMMWM_API int nMy32feetWidcommWM=0;
    
    // This is an example of an exported function.
    MY32FEETWIDCOMMWM_API int fnMy32feetWidcommWM(void)
    
    {
       
    return 42;
    
    }
    
    // This is the constructor of a class that has been exported.
    
    // see 32feetWidcommWM.h for the class definition
    CMy32feetWidcommWM::CMy32feetWidcommWM()
    
    { 
    return; 
    
    }

### 3.配置预编译宏(Preprocessor Definitions) ###

[![export-dll-2][]][export-dll-2 1]

封装DLL的项目会输出接口 \_\_declspec(dllexport) ，而调用方会输入接口 \_\_declspec(dllimport) ，见头文件定义。

### 4.配置输出lib文件 ###

[![export-dll-1][]][export-dll-1 1]

调用方需要链接该lib文件。

完成了。

本文转自Jake Lin博客园博客，原文链接：http://www.cnblogs.com/procoder/archive/2009/11/18/Windows-Mobile-Native-DLL.html，如需转载请自行联系原作者

[Windows Mobile_Wince_Windows Embedded CE_Native DLL_.NET Compact Framework]: http://www.cnblogs.com/procoder/archive/2009/11/09/Windows_Mobile_Native_DLL.html
[Windows Mobile_Native C_DLL]: http://www.cnblogs.com/procoder/archive/2009/09/25/Windows_Mobile_CPP_DLL.html
[export-dll-2]: /images/20220202/a4866ee19b2246faad218a511e01b7e1.png
[export-dll-2 1]: http://images.cnblogs.com/cnblogs_com/procoder/WindowsLiveWriter/WindowsMobileWinceWindowsEmbeddedCENativ_9E5D/export-dll-2_2.png
[export-dll-1]: /images/20220202/b532d4cfe97d4a2fb108531f37e975d9.png
[export-dll-1 1]: http://images.cnblogs.com/cnblogs_com/procoder/WindowsLiveWriter/WindowsMobileWinceWindowsEmbeddedCENativ_9E5D/export-dll-1_2.png