/** 
 * 检测是否使用手机访问 
 * @access public 
 * @return bool 
 */
function isMobile(){    
    if (isset($_SERVER['HTTP_VIA'])??'' && stristr($_SERVER['HTTP_VIA'], "wap")) {        
        return true;    
    } elseif ($_SERVER['HTTP_ACCEPT'] && strpos(strtoupper($_SERVER['HTTP_ACCEPT']), "VND.WAP.WML")) {
        return true;    
    } elseif (isset($_SERVER['HTTP_X_WAP_PROFILE'])??'' || isset($_SERVER['HTTP_PROFILE'])??'') {       
        return true;    
    } elseif ($_SERVER['HTTP_USER_AGENT'] && preg_match('/(blackberry|configuration\/cldc|hp |hp-|htc |htc_|htc-|iemobile|kindle|midp|mmp|motorola|mobile|nokia|opera mini|opera |Googlebot-Mobile|YahooSeeker\/M1A1-R2D2|android|iphone|ipod|mobi|palm|palmos|pocket|portalmmm|ppc;|smartphone|sonyericsson|sqh|spv|symbian|treo|up.browser|up.link|vodafone|windows ce|xda |xda_)/i', $_SERVER['HTTP_USER_AGENT'])) {        
        return true;   
    }    
    return false;
}