C# 爬虫----Cookies处理(Set-Cookie)

    /// <summary>
    /// cookie 助手
    /// </summary>
    public class cookiehelper
    {
        /// <summary>
        /// 解析cookie
        /// </summary>
        private static readonly regex regexsplitcookie2 = new regex(@"[^,][\s\s]+?;+[\s\s]+?(?=,\s)");

        /// <summary>
        /// 获取所有cookie 通过set-cookie
        /// </summary>
        /// <param name="setcookie"></param>
        /// <returns></returns>
        public static cookiecollection getcookiesfromheader(string setcookie)
        {
            var cookiecollection = new cookiecollection();
            //拆分cookie
            setcookie += ",t";//配合regexsplitcookie2 加入后缀
            var liststr = regexsplitcookie2.matches(setcookie);
            //循环遍历
            foreach (match item in liststr)
            {
                //根据; 拆分cookie 内容
                var cookieitem = item.value.split(';');
                var cookie = new cookie();
                for (var index = 0; index < cookieitem.length; index++)
                {
                    var info = cookieitem[index];
                    //第一个 默认 cookie name
                    //判断键值对
                    if (info.contains("="))
                    {
                        var indexk = info.indexof('=');
                        var name = info.substring(0, indexk).trim();
                        var val = info.substring(indexk + 1);
                        if (index == 0)
                        {
                            cookie.name = name;
                            cookie.value = val;
                            continue;
                        }
                        if (name.equals("domain", stringcomparison.ordinalignorecase))
                        {
                            cookie.domain = val;
                        }
                        else if (name.equals("expires", stringcomparison.ordinalignorecase))
                        {
                            datetime.tryparse(val, out var expires);
                            cookie.expires = expires;
                        }
                        else if (name.equals("path", stringcomparison.ordinalignorecase))
                        {
                            cookie.path = val;
                        }
                        else if (name.equals("version", stringcomparison.ordinalignorecase))
                        {
                            cookie.version = convert.toint32(val);
                        }
                    }
                    else
                    {
                        if (info.trim().equals("httponly", stringcomparison.ordinalignorecase))
                        {
                            cookie.httponly = true;
                        }
                    }
                }
                cookiecollection.add(cookie);
            }
            return cookiecollection;
        }

        /// <summary>
        /// 获取 cookies
        /// </summary>
        /// <param name="setcookie"></param>
        /// <param name="uri"></param>
        /// <returns></returns>
        public static string getcookies(string setcookie, uri uri)
        {
            //获取所有cookie
            var strcookies = string.empty;
            var cookies = getcookiesfromheader(setcookie);
            foreach (cookie cookie in cookies)
            {
                //忽略过期cookie
                if (cookie.expires < datetime.now && cookie.expires != datetime.minvalue)
                {
                    continue;
                }
                if (uri.host.contains(cookie.domain))
                {
                    strcookies += $"{cookie.name}={cookie.value}; ";
                }
            }
            return strcookies;
        }
    }