对“_imp__InitBizLib”的未定义引用

Question

当尝试在 XP 上使用 eclipse 编写的 C++ 程序使用第 3 方 SDK 时，出现上述错误。根据搜索，我了解到此错误是由链接器未正确指向 .dll 或 .lib 引起的。我已将这些项目的路径包含在环境变量 - PATH 中，也在 Eclipse 中的 Properties\C/C++ Build\Settings\MinGW C++ Linker\Libraries 下。这两项使用的路径是 C:\Program Files\Card Scanning Solutions\SDK

这是控制台输出：

**** Build of configuration Debug for project HelloWorld ****

**** Internal Builder is used for build               ****
g++ -IC:\Program Files\Card Scanning Solutions\SDK -O0 -g3 -Wall -c -fmessage-length=0 -lm -v -o src\BizScan.o ..\src\BizScan.cpp
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=c:/mingw/bin/../libexec/gcc/mingw32/4.6.1/lto-wrapper.exe
Target: mingw32
Configured with: ../gcc-4.6.1/configure --enable-languages=c,c++,fortran,objc,obj-c++ --disable-sjlj-exceptions --with-dwarf2 --enable-shared --enable-libgomp --disable-win32-registry --enable-libstdcxx-debug --enable-version-specific-runtime-libs --build=mingw32 --prefix=/mingw
Thread model: win32
gcc version 4.6.1 (GCC) 
COLLECT_GCC_OPTIONS='-I' 'C:\Program Files\Card Scanning Solutions\SDK' '-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-v' '-o' 'src\BizScan.o' '-shared-libgcc' '-mtune=i386' '-march=i386'
 c:/mingw/bin/../libexec/gcc/mingw32/4.6.1/cc1plus.exe -quiet -v -I C:\Program Files\Card Scanning Solutions\SDK -iprefix c:\mingw\bin\../lib/gcc/mingw32/4.6.1/ -dD ..\src\BizScan.cpp -quiet -dumpbase BizScan.cpp -mtune=i386 -march=i386 -auxbase-strip src\BizScan.o -g3 -O0 -Wall -version -fmessage-length=0 -o C:\DOCUME~1\Game\LOCALS~1\Temp\ccwufpbm.s
GNU C++ (GCC) version 4.6.1 (mingw32)
    compiled by GNU C version 4.6.1, GMP version 5.0.1, MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=64 --param ggc-min-heapsize=65307
ignoring nonexistent directory "c:\mingw\bin\../lib/gcc/mingw32/4.6.1/../../../../mingw32/include"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.6.1/include/c++"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.6.1/include/c++/mingw32"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.6.1/include/c++/backward"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.6.1/include"
ignoring duplicate directory "/mingw/lib/gcc/mingw32/4.6.1/../../../../include"
ignoring duplicate directory "c:/mingw/lib/gcc/../../include"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.6.1/include-fixed"
ignoring nonexistent directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/4.6.1/../../../../mingw32/include"
ignoring duplicate directory "/mingw/include"
#include "..." search starts here:
#include <...> search starts here:
 C:\Program Files\Card Scanning Solutions\SDK
 c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++
 c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/mingw32
 c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include/c++/backward
 c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include
 c:\mingw\bin\../lib/gcc/mingw32/4.6.1/../../../../include
 c:\mingw\bin\../lib/gcc/mingw32/4.6.1/include-fixed
End of search list.
GNU C++ (GCC) version 4.6.1 (mingw32)
    compiled by GNU C version 4.6.1, GMP version 5.0.1, MPFR version 2.4.1, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=64 --param ggc-min-heapsize=65307
Compiler executable checksum: 8e56a7b4b7f3db333ff95dd4b2d788a4
COLLECT_GCC_OPTIONS='-I' 'C:\Program Files\Card Scanning Solutions\SDK' '-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-v' '-o' 'src\BizScan.o' '-shared-libgcc' '-mtune=i386' '-march=i386'
 c:/mingw/bin/../lib/gcc/mingw32/4.6.1/../../../../mingw32/bin/as.exe -o src\BizScan.o C:\DOCUME~1\Game\LOCALS~1\Temp\ccwufpbm.s
COMPILER_PATH=c:/mingw/bin/../libexec/gcc/mingw32/4.6.1/;c:/mingw/bin/../libexec/gcc/;c:/mingw/bin/../lib/gcc/mingw32/4.6.1/../../../../mingw32/bin/
LIBRARY_PATH=c:/mingw/bin/../lib/gcc/mingw32/4.6.1/;c:/mingw/bin/../lib/gcc/;c:/mingw/bin/../lib/gcc/mingw32/4.6.1/../../../../mingw32/lib/;c:/mingw/bin/../lib/gcc/mingw32/4.6.1/../../../;/mingw/lib/
COLLECT_GCC_OPTIONS='-I' 'C:\Program Files\Card Scanning Solutions\SDK' '-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-v' '-o' 'src\BizScan.o' '-shared-libgcc' '-mtune=i386' '-march=i386'
g++ -LC:\Program Files\Card Scanning Solutions\SDK -lm -o HelloWorld.exe src\HelloWorld.o src\BizScan.o
src\BizScan.o: In function `ZN7BizScan4InitEv':
C:\Documents and Settings\Game\workspace\HelloWorld\Debug/../src/BizScan.cpp:20: undefined reference to `_imp__UseFixedModel'
C:\Documents and Settings\Game\workspace\HelloWorld\Debug/../src/BizScan.cpp:22: undefined reference to `_imp__SetTwainScanner'
C:\Documents and Settings\Game\workspace\HelloWorld\Debug/../src/BizScan.cpp:23: undefined reference to `_imp__InitScanLib'
C:\Documents and Settings\Game\workspace\HelloWorld\Debug/../src/BizScan.cpp:27: undefined reference to `_imp__InitImageLib'
C:\Documents and Settings\Game\workspace\HelloWorld\Debug/../src/BizScan.cpp:31: undefined reference to `_imp__InitBizLib'
src\BizScan.o: In function `~BizScan':
C:\Documents and Settings\Game\workspace\HelloWorld\Debug/../src/BizScan.cpp:39: undefined reference to `_imp__UnInitScanLib'
collect2: ld returned 1 exit status
Build error occurred, build is stopped
Time consumed: 5648  ms.  

这是 BizScan.cpp：

/*
 * BizScan.cpp
 *
 *  Created on: Feb 13, 2012
 *      Author: TFB
 */

#include "BizScan.h"
#include "slibexp.h" // ScanLib SDK header file
#include "..\header_lib\BizExp.h" // ScanLib SDK header file
#include "..\header_lib\ImageExp.h" // ScanLib SDK header file
#include "CSSN.h"
#include "windef.h"

BizScan::BizScan() {
    BizScan::Init();
}

const char* BizScan::Init() {
    UseFixedModel(11);
    const char *scannerSelected = "WIA-A6 Scanner 735";
    int result = SetTwainScanner(scannerSelected);
    result = InitScanLib(CSSN::GetSDKLicense().c_str());
    if(result < 0 && result != -13){
        return ScannerErrors(result);
    } else {
        result = InitImageLib(CSSN::GetSDKLicense().c_str());//initialize Image Lib SDK
        if(result < 0 && result != -13)//if error
            return ImageErrors(result);//call image lib sdk

        result = InitBizLib(CSSN::GetSDKLicense().c_str());//initialize Biz Card Lib Scanner SDK
        if(result < 0 && result != -13)//if error
            return BizErrors(result);//call biz card scanner Lib SDK error handler
    }
    return "Successful Initialization !!";
}

BizScan::~BizScan() {
    UnInitScanLib();
}

这是 BizScan.h：

/*
 * BizScan.h
 *
 *  Created on: Feb 13, 2012
 *      Author: TFB
 */

#ifndef BIZSCAN_H_
#define BIZSCAN_H_

#include "windef.h"

typedef HINSTANCE hDLL;

class BizScan {
private:

public:
    BizScan();
    virtual ~BizScan();
    const char* Init() ;
};

#endif /* BIZSCAN_H_ */

的相关部分：

/*/////////////////////////////////////////////////////////////////////
//
// SLibExp.h
//
// Card Scanning Solutions (LLC)
// All Rights Reserved
//
/////////////////////////////////////////////////////////////////////*/
#ifndef SLIBEXP_H
#define SLIBEXP_H


#ifdef SDLL
#define SDLL_EXP __declspec( dllexport )
#else
#define SDLL_EXP __declspec( dllimport )
#endif

// Functions Prototypes
#if defined __cplusplus || defined c_plusplus
extern "C" 
{
#endif

SDLL_EXP void UseFixedModel(int val);
SDLL_EXP short SetTwainScanner(const char *szStr);
SDLL_EXP short InitScanLib(const char * license);
IMAGE_EXPORT short InitImageLib(const char *licanse);
SDLL_EXP short UnInitScanLib();

#if defined __cplusplus || defined c_plusplus
}; 
#endif

#endif  /* SLIBEXP_H */

这里是slibexp.h 控制台输出中引用的其他两种方法都是在同一文件夹（项目根目录）中的其他头文件中定义的。它们的定义如下：

IMAGE_EXPORT short InitImageLib(const char *licanse);
extern "C" BIZ_EXPORT short InitBizLib(const char *license);

是否有其他地方需要链接这些 .dll。我尝试过使用 LoadLibrary() 方法，但该方法因不属于范围而被拒绝。我应该如何链接到这些 dll？感谢您提供的任何指导。

Answer 1

查看您显示的输出，这是相关的命令：

g++ -LC:\Program Files\Card Scanning Solutions\SDK -lm -o HelloWorld.exe src\HelloWorld.o src\BizScan.o

它包括库的路径，但没有实际库本身的引用。我不知道该库的名称是什么，但假设它是 libBizLib.a，该命令末尾应该有 -lBizLib ；或者，如果您想链接 dll，则可以使用其全名（不带 -l）。

（顺便说一下，您提到了该库的 .lib 扩展名。这通常表示 Visual Studio 库。您确定您拥有的版本与 MinGW 兼容吗？）

Answer 2

我最近也发生了类似的问题。这似乎是因为编译器的差异。该库是使用 MinGW w64 的一个版本构建的，而我的版本足够不同，以至于我无法在该库附带的 .a 文件中进行编译。

但是您可以使用 LoadLibrary 在运行时使用 dll，但是在调用它时必须更加明确。那么 dll 无法加载的主要方式是文件不在 dll 加载路径中或者 dll 的位类型错误（32 位 v 64 位）。

希望有帮助。