CWnd和HWND句柄的区别
CWnd只能对本控件的属性进行操作, HWND还可以对子控件进行操作
MFC内部函数一般用CWnd ,全局函数(win32api)一般用HWND
CWnd*转化为HWND
CWnd* pWnd = GetDlgItem(IDC_BUTTON2);
HWND hWnd = pWnd->GetSafeHwnd();//CWnd*转化为HWND
::SetWindowText(hWnd,_T("测试"));
HWND hWnd = GetSafeHwnd();//获取代码所在控件的句柄
::SetWindowText(hWnd, _T("测试"));