求问给位大大_子对话框的消息事件响应无效有关问题

求问给位大大__子对话框的消息事件响应无效问题？

BOOL CWinmain::InitInstance()

{

	m_pMainWnd = new CTestframe;

	m_pMainWnd->ShowWindow(m_nCmdShow);

	m_pMainWnd->UpdateWindow();           //这个是主要的绘图窗口


	pDlg = new CDialogEx;

	pDlg->Create(IDD_DIALOG1);

	pDlg->ShowWindow(m_nCmdShow);

	pDlg->UpdateWindow();                 //这个是子对话框了，要用这个对话框对主窗口发送信息


	return TRUE;

}

--------------以下是对话框的类

class CDialogtest : public CDialogEx

{

	DECLARE_DYNAMIC(CDialogtest)


public:

	CDialogtest(CWnd* pParent = NULL);   

	virtual ~CDialogtest();


	enum { IDD = IDD_DIALOG1 };


protected:

	virtual void DoDataExchange(CDataExchange* pDX);   


	DECLARE_MESSAGE_MAP()

public:

	afx_msg void OnEnChangeEdit1();

	afx_msg void OnBnClickedButton2();

	afx_msg void OnBnDoubleclickedButton2();


	virtual BOOL PreTranslateMessage(MSG *pMsg );

};

-------------------------------一下是对话框的.CPP

IMPLEMENT_DYNAMIC(CDialogtest, CDialogEx)


CDialogtest::CDialogtest(CWnd* pParent /*=NULL*/)

	: CDialogEx(CDialogtest::IDD, pParent)

	, m_csSubStr(_T(""))

{


}


CDialogtest::~CDialogtest()

{

}


void CDialogtest::DoDataExchange(CDataExchange* pDX)

{

	CDialogEx::DoDataExchange(pDX);

	DDX_Text(pDX, IDC_EDIT1, m_csSubStr);

}



BEGIN_MESSAGE_MAP(CDialogtest, CDialogEx)

	ON_EN_CHANGE(IDC_EDIT1, &CDialogtest::OnEnChangeEdit1)

	ON_BN_CLICKED(IDC_BUTTON2, &CDialogtest::OnBnClickedButton2)

	ON_BN_DOUBLECLICKED(IDC_BUTTON2, &CDialogtest::OnBnDoubleclickedButton2)

END_MESSAGE_MAP()





void CDialogtest::OnEnChangeEdit1()

{


}





void CDialogtest::OnBnClickedButton2()

{

	UpdateData(TRUE);

	UpdateData(FALSE);

}



void CDialogtest::OnBnDoubleclickedButton2()

{

}


BOOL CDialogtest::PreTranslateMessage(MSG *pMsg )

{

	return TRUE;

}

究竟哪里不对啊，PreTranslateMessage和OnBnClickedButton2()等，都点击无法响应啊，求大神帮助
------解决方案--------------------
pDlg = new CDialogEx;
--》
pDlg = new CDialogtest;