请教关于DLL问题

请教关于DLL问题
我建立了一个DLL内容如下

<<<<<<<<<CmView.H>>>>>>>>>
#pragma once
class AFX_EXT_CLASS CmView : public CView
{
public:
DECLARE_DYNAMIC(CmView)
CmView();
~CmView();
};

<<<<<<<<<<CmView.Cpp>>>>>>>>>
#include "stdafx.h"
#include "CmView.h"
IMPLEMENT_DYNAMIC(CmView,CView)
CmView::CmView()
{}

CmView::~CmView()
{}

调用
#include "CmView.h"
#pragma comment(lib,"Dll.lib")
class InfoView : public CmView
{
...................
}

报错如下:
InfoView.obj : error LNK2001: unresolved external symbol "public: static struct CRuntimeClass const CmView::classCmView" (?classCmView@CmView@@2UCRuntimeClass@@B)

如何解决这个问题.谢谢:)