格式化参数格式化成url参数

/**
     * 格式化参数格式化成url参数
     */
    public static function ToUrlParams($data)
    {
        $buff = "";
        foreach ($data as $k => $v)
        {
            if($k != "sign" && $v != "" && !is_array($v)){
                $buff .= $k . "=" . $v . "&";
            }
        }

        $buff = trim($buff, "&");
        return $buff;
    }