c++ - Accessing a vector from a DLL -

am working in project have build library , use library in main function.the library .dll , has 7 headers , 5 source files.in header declared vector , implemented in 1 of source files.since have access vector in main program declared global in source file , extern in header file.now after build dll , linked main program cannot able access vector showing "unresolved external".i don't know mistake working load time linking getting error during run time linking.please welcomed.my code this

ntfs-struct.h            ---- > library header  _cdecl(dllexports) extern std::vector<std::string>files;    ntfs-search.cpp             ------ > library source file  #include "ntfs-struct.h"  vector<string>files;         ---> global vector accessing in main program   mft-list   --- > main program  #include "ntfs-struct.h"   cout << "vector size" << files.size(); 

p.s since used dll link main program has run time linking set configuration in vs2010(platform working) delay dll.

use macro distinguish "build dll" case "build exe" one.

dll header:

// ntfs-struct.h #ifdef build_dll #define declspec_dll __declspec( dllexport ) #else #define declspec_dll __declspec( dllimport ) #endif  declspec_dll extern std::vector<std::string> files; 

dll implementation:

// ntfs-search.cpp #define build_dll #include "ntfs-struct.h" std::vector<std::string> files; 

exe:

// mft-list.cpp #include "ntfs-struct.h"  cout << "vector size" << files.size(); 

edit: how use exported function taking vector reference:

declspec_dll void updatevector( std::vector<std::string> & files ); 

if experience heap corruption, may because don't build exe , dll same , good options c runtime library. options must be : multi-threaded dll (/md) or multi-threaded debug dll (/mdd) set theses options in property->c++->code generation

edit2: how link

method one: use #pragma directive in dll header.

#pragma lib( comment, "mylib.lib" ) 

method two: use dependencies settings.

1. make dll project dependency of exe in "project dependencies" solution
2. set yes link library dependencies in linker->general properties exe

method three: explicitly add library file (lib)

go linker->input properties , add lib file additional dependencies list, exe