/**
* 合并默认参数和额外参数
* @param array $params 默认参数
* @param array/string $param 额外参数
* @return array:
*/
protected function param($params, $param)
{
$params = parent::param($params, $param);
/* 签名 */
ksort($params);
$param = array();
foreach ($params as $key => $value) {
$param[] = "{$key}={$value}";
}
$sign = implode('', $param) . $this->appSecret;
$params['sig'] = md5($sign);
return $params;
}