vector.push_back类对象 - 错误LNK2019

Question

Visual Studio 2010 MFC - Unicode - 共享DLL中的MFC - / SUBSYSTEM：WINDOWS

//cword.hpp
//---------
#pragma once
#include <atlstr.h>

class CWord
{
public:
  CWord();
  CWord(const CString word);
  ~CWord();
};

//cword.cpp
//---------
#include "CWord.h"

CWord::CWord() { }

CWord::CWord(const CString word)
{
  m_word = word;
}

//"CWordSearchDoc.h
-------------------
#include <vector>
#include "CWord.h"

class CWordSearchDoc : public CDocument
{
private:
  std::vector< CWord > m_word_list;
public:
  void add_word(CString word);
};

//"CWordSearchDoc.cpp
//-------------------
#include "CWordSearchDoc.h"

void CWordSearchDoc::add_word(CString word)
{
  CWord new_word( word ); 

  m_word_list.push_back( new_word ); // -- link error LNK2019

  // ......
  m_word_list.push_back( CWord() ); // -- no error
}

1＆gt; CWordsearchDoc.obj：错误LNK2019：未解析的外部符号＆＃34; public：__ thiscall CWord :: CWord（类ATL :: CStringT＆gt;＆gt;）＆＃34; （?? 0CWord @@ QAE @ V'$ @ CStringT _WV？$ @ StrTraitMFC_DLL _WV？$ @ ChTraitsCRT @ _W ATL @@@@@ ATL @@@ Z） 在函数＆＃34; public中引用：void __thiscall CWordSearchDoc :: add_word（类ATL :: CStringT＆gt;＆gt;）＆＃34; （？add_word @ @@ CWordSearchDoc QAEXV？$ CStringT @ _WV？$ StrTraitMFC_DLL @ _WV？$ ChTraitsCRT @ _W @ ATL @@@@@ ATL @@@ Z）

在dos应用程序中复制了相同的代码并且发生了同样的错误。任何帮助表示感谢。 ：）