求大神看看帮忙改正错误，获取网页信息的问题

Question

using System.Text;
using System.IO;
using System.Net;
using System.Text.RegularExpressions;namespace TestQueryTrainTicketPrice
{
    public  class TrainTicketPriceQuery
    {
        private static string setCookie = string.Empty;        /// <summary>
        /// </summary>
        public static string DoGetTrainTicketLeft(string trainTeleCode,string fromtime,string rand_Code)
        {
            string result = string.Empty;
            try
            {
                //0-车次 1-时间 2-验证码 
                string trainTicketLeftUrl =@"https://kyfw.12306.cn/otn/queryTrainInfo/query?leftTicketDTO.train_no={0}&leftTicketDTO.train_date={1}&rand_code={2}";               trainTicketLeftUrl = string.Format(trainTicketLeftUrl,  trainTeleCode,fromtime ,rand_Code );
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(trainTicketLeftUrl);
                request.Accept = @"application/json, text/javascript, */*";
                request.UserAgent = @"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0))";
                request.Referer = @"https://kyfw.12306.cn/otn/queryTrainInfo/init";
                request.ContentType = @"application/json;charset=UTF-8";
                request.Method = "GET";
                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                {
                    using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
                    {
                        result = reader.ReadToEnd();
                    }
                }
            }
            catch { }
            return result;
        }
        /// <summary>
        /// 票价查询验证码
        /// </summary>
        /// <returns></returns>
        public static string DoGetTrainTicketPriceRandCodeImage()
        {
            string resultImage = string.Empty;            try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(@"https://kyfw.12306.cn/otn/passcodeNew/getPassCodeNew.do?module=login&rand=sjrand");                request.Accept = @"image/png, image/svg+xml, image/*;q=0.8, */*;q=0.5";                request.UserAgent = @"Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)";                request.Referer = @"https://kyfw.12306.cn/otn/queryTrainInfo/init";                request.Method = "GET";                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                {
                    setCookie = response.GetResponseHeader("Set-cookie");                    setCookie = Regex.Replace(setCookie, "path(?:[^,]+),?", "", RegexOptions.IgnoreCase);                    using (Stream reader = response.GetResponseStream())
                    {
                        string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, new Random().Next(10000, 99999) + @"queryTicketPrice.JPEG");
                        using (FileStream file = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
                        {
                            reader.CopyTo(file);
                        }                        resultImage = path;                    }
                }
            }
            catch { }            return resultImage;
        }
    }
}
这是函数

Answer 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;namespace TestQueryTrainTicketPrice
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();            this.Loaded += new RoutedEventHandler(MainWindow_Loaded);
        }        void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            string date = DateTime.Now.AddDays(0).ToString(@"yyyy-MM-dd");            this.txtDate.Text = date;            InitialRandCode();
        }        private void InitialRandCode()
        {
            //初始化验证码
            string randCodeImageUrl = TrainTicketPriceQuery.DoGetTrainTicketPriceRandCodeImage();            if (!string.IsNullOrEmpty(randCodeImageUrl))
            {
                ImageSource src = (ImageSource)(new ImageSourceConverter().ConvertFromString(randCodeImageUrl));                this.imageRandCode.Source = src;
            }
        }        /// <summary>
        /// 开始查询
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            string trainTeleCode = this.trainTeleCode.Text.ToString();            string randCode = this.txtRandCode.Text.ToString();            string fromtime = this.txtDate.Text;            if (string.IsNullOrEmpty(trainTeleCode) || string.IsNullOrEmpty(randCode) || string.IsNullOrEmpty(fromtime))
            {
                MessageBox.Show("参数不完整，请重新填写！");                return;
            }            DateTime fromDate = DateTime.Parse(fromtime);            string queryResult = TrainTicketPriceQuery.DoGetTrainTicketLeft(trainTeleCode,fromtime, randCode);            System.Windows.Documents.FlowDocument doc = rtxResultInfo.Document;            doc.Blocks.Clear();            rtxResultInfo.AppendText(queryResult);        }        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            InitialRandCode();
        }        private void rtxResultInfo_TextChanged(object sender, TextChangedEventArgs e)
        {        }        private void txtRandCode_TextChanged(object sender, TextChangedEventArgs e)
        {        }
    }
}
这是操作

Answer 2

获得验证码时没传cookie2个request 设置cookiecontainer为同一个