CString str;
    if(pMsg->message==WM_CHAR && pMsg->hwnd==this->mc_source.m_hWnd)
    {
        char num=(TCHAR)pMsg->wParam;
        if(!(CheckNummer(num) || num=='.' || num==VK_BACK))
            return true;
        if(num=='.')
        {
            mc_source.GetWindowText(str);            //得到当前文本
            if(str.Find(".",0)>=0)                    //测试串中是否已有"."字符
                return true;