怎样在Dialog里面，动态添加和删除按钮

参考：

工作中遇到对话框中动态添加和删除（隐藏、显示）按钮问题

#define IDC_GROUPBOX1 1001

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
 CAboutDlg();

// Dialog Data
 //{{AFX_DATA(CAboutDlg)
 enum { IDD = IDD_ABOUTBOX };
 //}}AFX_DATA

 // ClassWizard generated virtual function overrides
 //{{AFX_VIRTUAL(CAboutDlg)
 protected:
 virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
 //}}AFX_VIRTUAL

// Implementation
protected:
 //{{AFX_MSG(CAboutDlg)
  // No message handlers
 //}}AFX_MSG
 
 DECLARE_MESSAGE_MAP()
 afx_msg BOOL OnInitDialog();
 afx_msg void DelButton();
 
 CButton *m_pGroupBox1;
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
 //{{AFX_DATA_INIT(CAboutDlg)
 //}}AFX_DATA_INIT
}

BOOL CAboutDlg::OnInitDialog()
{ 
/* if( m_pGroupBox1 != NULL )
 {
  delete m_pGroupBox1;
  m_pGroupBox1 = NULL;
 }
*/ m_pGroupBox1 = new CButton;
 m_pGroupBox1->Create( _T( "Test" ), BS_PUSHBUTTON | BS_CENTER | WS_VISIBLE, CRect( CPoint( 50, 50 ), CSize( 100, 30 ) ), this, IDC_GROUPBOX1 );
 m_pGroupBox1->ShowWindow(SW_SHOW);

/*  m_pGroupBox1->DestroyWindow();
 delete m_pGroupBox1;
 m_pGroupBox1 = NULL;
*/

 return TRUE;
}

void CAboutDlg::DelButton()
{
 HWND hWnd = GetSafeHwnd();
 if( m_pGroupBox1 != NULL )
 {
  m_pGroupBox1->DestroyWindow();
  delete m_pGroupBox1;
  m_pGroupBox1 = NULL;
 }
 //CButton *pBtn = GetDlgItem(IDOK, &hWnd);
 GetDlgItem(IDOK)->ShowWindow(HIDE_WINDOW); //Hide "OK" Button
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
 CDialog::DoDataExchange(pDX);
 //{{AFX_DATA_MAP(CAboutDlg)
 //}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
 //{{AFX_MSG_MAP(CAboutDlg)
  // No message handlers
  ON_WM_SYSCOMMAND()
 //}}AFX_MSG_MAP
 ON_COMMAND(IDC_GROUPBOX1, DelButton)
END_MESSAGE_MAP()

*****更改默认菜单名称
CMenu* pSysMenu = GetSystemMenu(FALSE);
 if (pSysMenu != NULL)
 {
  //pSysMenu->DeleteMenu(SC_MAXIMIZE,MF_BYCOMMAND);
  //pSysMenu->DeleteMenu(SC_SIZE,MF_BYCOMMAND);
  // end added

  CString strAboutMenu("Hello World");
  
  if (!strAboutMenu.IsEmpty())
  {
   pSysMenu->InsertMenu(SC_CLOSE, MF_BYCOMMAND, IDM_ABOUTBOX, strAboutMenu);
   pSysMenu->InsertMenu(SC_CLOSE, MF_BYCOMMAND | MF_SEPARATOR);
  }

  ******新增菜单
 　CMenu menu;  
  if (menu.LoadMenu(uMainMenuID))
  {
   CMenu* p_menu = menu.GetSubMenu(1);
   if (p_menu)
   {
    CString str = _T("Change Skin...");
    //p_menu->GetMenuString(ID_CHANGE_SKIN, str, MF_BYCOMMAND);
    pSysMenu->AppendMenu(MF_STRING, ID_CHANGE_SKIN, str);
   }
  }
 }

*****删除菜单
CMenu* pMainMenu= GetMenuBar()->GetMenu();
 if(pMainMenu)
 {
  CMenu* pChildMenu = pMainMenu->GetSubMenu(3);
  if(pChildMenu)
   pChildMenu->DeleteMenu(ID_HELP＿ABOUT,MF_BYCOMMAND);
 }