WINAPI - 编译时出错LNK2019，LNK2001，LNK1120。

WINAPI非常新，所以要温柔。WINAPI - 编译时出错LNK2019，LNK2001，LNK1120。

我已经阅读了Jeffrey Richter的“通过C/C++编写的Windows”一书，现在我正在尝试做一些他在书中描述的基本DLL内容。

在第19章中，他举了一个简单的例子。我试图让这个例子，但建设项目时，我不断收到这三个错误：

Error 1 error LNK2019: unresolved external symbol __imp__Add referenced in function [email protected]  
Error 2 error LNK2001: unresolved external symbol __imp__g_nResult 
Error 3 error LNK1120: 2 unresolved externals

我有三个文件：

DLLChapter19.h：

#ifdef MYLIBAPI 
#else 
#define MYLIBAPI extern "C" __declspec(dllimport) 
#endif 
MYLIBAPI int g_nResult; 
MYLIBAPI int Add(int nLeft, int nRight);

DLLChapter19.cpp：

//#include <Windows.h> //apparently the complier says that I should use stdafx.h instead(?) 
#include "stdafx.h" 
#define MYLIBAPI extern "C" __declspec(dllexport) 
#include "DLLChapter19.h" 

int g_nResult; 

int Add(int nLeft, int nRight) { 
    g_nResult = nLeft + nRight; 
    return(g_nResult); 
}

然后（在另一个项目中，但在相同的解决方案中）。

DLLChapter19EXE.cpp：

//#include <Windows.h> //apparently the complier says that I should use stdafx.h instead? 
#include "stdafx.h" 
#include <strsafe.h> 
#include <stdlib.h> 

#include "C:\Users\Kristensen\Documents\Visual Studio 2012\Projects\DLLChapter19\DLLChapter19\DLLChapter19.h" 

int WINAPI _tWinMain(HINSTANCE , HINSTANCE , LPTSTR, int) { 

    int nLeft = 10, nRight = 25; 

    TCHAR sz[100]; 
    StringCchPrintf(sz, _countof(sz), TEXT("%d +%d =%d"), 
     nLeft, nRight, Add(nLeft, nRight)); 
    MessageBox(NULL, sz, TEXT("Calculation"), MB_OK); 

    StringCchPrintf(sz, _countof(sz), 
     TEXT("The result from the last Add is: %d"), g_nResult); 
    MessageBox(NULL, sz, TEXT("Last Result"), MB_OK); 
    return(0); 
}

为什么会出现这三个错误？我看通过“DUMPBIN -exports”的DLLChapter19.dll，它看起来不错，与2倍输出的符号：

C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\amd64>dumpbin -export 
s DLLChapter19.dll 
Microsoft (R) COFF/PE Dumper Version 11.00.60315.1 
Copyright (C) Microsoft Corporation. All rights reserved. 


Dump of file DLLChapter19.dll 

File Type: DLL 

    Section contains the following exports for DLLChapter19.dll 

    00000000 characteristics 
    5184F8EE time date stamp Sat May 04 14:02:54 2013 
     0.00 version 
      1 ordinal base 
      2 number of functions 
      2 number of names 

    ordinal hint RVA  name 

      1 0 000110C3 Add 
      2 1 00017128 g_nResult 

    Summary 

     1000 .data 
     1000 .idata 
     2000 .rdata 
     1000 .reloc 
     1000 .rsrc 
     4000 .text 
     10000 .textbss

我已经搜查，搜查，但找不到我的问题的解决方案。

来源

2013-05-04 Theis Kristensen