/**
* 获取当前页面完整URL地址
*/
private function _get_url()
{
$sys_protocal = isset($_SERVER['SERVER_PORT']) && $_SERVER['SERVER_PORT'] == '443' ? 'https://' : 'http://';
$php_self = $_SERVER['PHP_SELF'] ? Sms::_safe_replace($_SERVER['PHP_SELF']) : Sms::_safe_replace($_SERVER['SCRIPT_NAME']);
$path_info = isset($_SERVER['PATH_INFO']) ? Sms::_safe_replace($_SERVER['PATH_INFO']) : '';
$relate_url = isset($_SERVER['REQUEST_URI']) ? Sms::_safe_replace($_SERVER['REQUEST_URI']) : $php_self . (isset($_SERVER['QUERY_STRING']) ? '?' . Sms::_safe_replace($_SERVER['QUERY_STRING']) : $path_info);
return $sys_protocal . (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '') . $relate_url;
}