EmergenceDoc.obj:错误LNK2019:未解析的外部符号

为了学习C++，我正在VS2010中创建一个简单的MFC文本编辑器，但遇到了一些障碍。。。。

具体来说，我在构建日志中得到以下错误：

1>  Generating Code...
1>Link:
1>     Creating library C:UsersAlvinDocumentsVisual Studio 2010ProjectsEmergenceDebugEmergenceHandlers.lib and object C:UsersAlvinDocumentsVisual Studio 2010ProjectsEmergenceDebugEmergenceHandlers.exp
1>EmergenceDoc.obj : error LNK2019: unresolved external symbol "public: __thiscall CEmergenceCntrItem::CEmergenceCntrItem(struct _reobject *,class CEmergenceDoc *)" (??0CEmergenceCntrItem@@QAE@PAU_reobject@@PAVCEmergenceDoc@@@Z) referenced in function "public: virtual class CRichEditCntrItem * __thiscall CEmergenceDoc::CreateClientItem(struct _reobject *)const " (?CreateClientItem@CEmergenceDoc@@UBEPAVCRichEditCntrItem@@PAU_reobject@@@Z)
1>C:UsersAlvinDocumentsVisual Studio 2010ProjectsEmergenceDebugEmergenceHandlers.dll : fatal error LNK1120: 1 unresolved externals
1> 
1>Build FAILED.
1>
1>Time Elapsed 00:00:06.52
========== Rebuild All: 1 succeeded, 1 failed, 0 skipped ==========

以下是出现CEmergeCntrItem的所有文件。。。。

cntritem.h:

#include "afxrich.h"
#include "Resource.h"
class CEmergenceDoc;
class CEmergenceView;
class CEmergenceCntrItem : public CRichEditCntrItem
{
    DECLARE_SERIAL(CEmergenceCntrItem)
public:
    CEmergenceCntrItem(REOBJECT* preo = NULL, CEmergenceDoc* pContainer = NULL);
public:
    CEmergenceDoc* GetDocument()
        { return (CEmergenceDoc*)COleClientItem::GetDocument(); }
    CEmergenceView* GetActiveView()
        { return (CEmergenceView*)COleClientItem::GetActiveView(); }
    // ClassWizard generated virtual function overrides
    //{{AFX_VIRTUAL(CWordPadCntrItem)
    public:
    protected:
    //}}AFX_VIRTUAL
// Implementation
public:
#ifdef _DEBUG
        virtual void AssertValid() const;
    virtual void Dump(CDumpContext& dc) const;
#endif
};

EmergencyView.cpp:

#include "afxrich.h"
#pragma once
class CEmergenceCntrItem;
class CEmergenceView : public CRichEditView
{
protected: // create from serialization only
    CEmergenceView();
    DECLARE_DYNCREATE(CEmergenceView)
public:
    CEmergenceDoc* GetDocument() const;
public:
public:
    virtual void OnDraw(CDC* pDC);  // overridden to draw this view
    virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
protected:
    virtual BOOL OnPreparePrinting(CPrintInfo* pInfo);
    virtual void OnBeginPrinting(CDC* pDC, CPrintInfo* pInfo);
    virtual void OnEndPrinting(CDC* pDC, CPrintInfo* pInfo);
public:
    virtual ~CEmergenceView();
#ifdef _DEBUG
        virtual void AssertValid() const;
    virtual void Dump(CDumpContext& dc) const;
#endif
protected:
protected:
    afx_msg void OnFilePrintPreview();
    afx_msg void OnRButtonUp(UINT nFlags, CPoint point);
    afx_msg void OnContextMenu(CWnd* pWnd, CPoint point);
    DECLARE_MESSAGE_MAP()
public:
    afx_msg void OnMutateGroup();
};
#ifndef _DEBUG  // debug version in EmergenceView.cpp
inline CEmergenceDoc* CEmergenceView::GetDocument() const
   { return reinterpret_cast<CEmergenceDoc*>(m_pDocument); }
#endif

紧急Doc.cpp

#include "stdafx.h"
#include "Emergence.h"
#include "EmergenceDoc.h"
#include "CntrItem.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
IMPLEMENT_DYNCREATE(CEmergenceDoc, CRichEditDoc)
BEGIN_MESSAGE_MAP(CEmergenceDoc, CRichEditDoc)
    //{{AFX_MSG_MAP(CMyWordDoc)
        // NOTE - the ClassWizard will add and remove mapping macros here.
        //    DO NOT EDIT what you see in these blocks of generated code!
    //}}AFX_MSG_MAP
    // Enable default OLE container implementation
    ON_UPDATE_COMMAND_UI(ID_OLE_EDIT_LINKS, 
    CRichEditDoc::OnUpdateEditLinksMenu)
    ON_COMMAND(ID_OLE_EDIT_LINKS, CRichEditDoc::OnEditLinks)
    ON_UPDATE_COMMAND_UI_RANGE(ID_OLE_VERB_FIRST, 
    ID_OLE_VERB_LAST, CRichEditDoc::OnUpdateObjectVerbMenu)
END_MESSAGE_MAP()
CEmergenceDoc::CEmergenceDoc()
{
}
CEmergenceDoc::~CEmergenceDoc()
{
}
BOOL CEmergenceDoc::OnNewDocument()
{
    if (!CRichEditDoc::OnNewDocument())
        return FALSE;
    return TRUE;
}
CRichEditCntrItem* CEmergenceDoc::CreateClientItem(REOBJECT* preo) const
{
    return new CEmergenceCntrItem(preo, (CEmergenceDoc*) this);
}
void CEmergenceDoc::Serialize(CArchive& ar)
{
    CRichEditDoc::Serialize(ar);
}

CntrItem.cpp

#include "stdafx.h"
#include "Emergence.h"
#include "EmergenceDoc.h"
#include "EmergenceView.h"
#include "cntritem.h"
#ifdef _DEBUG
#undef THIS_FILE
static char BASED_CODE THIS_FILE[] = __FILE__;
#endif
IMPLEMENT_SERIAL(CEmergenceCntrItem, CRichEditCntrItem, 0)
CEmergenceCntrItem::CEmergenceCntrItem(REOBJECT *preo, CEmergenceDoc* pContainer)
    : CRichEditCntrItem(preo, pContainer)
{
}
#ifdef _DEBUG
void CEmergenceCntrItem::AssertValid() const
{
        CRichEditCntrItem::AssertValid();
}
void CEmergenceCntrItem::Dump(CDumpContext& dc) const
{
    CRichEditCntrItem::Dump(dc);
}
#endif

如有任何帮助，我们将不胜感激。