获取最新汇率

class Program
  {
      public class ExRate
      {
          public string bank { get; set; }
          public string currency { get; set; }
          public string code { get; set; }
          public decimal? currencyUnit { get; set; }
          public decimal? cenPrice { get; set; }
          public decimal? buyPrice1 { get; set; }
          public decimal? sellPrice1 { get; set; }
          public decimal? buyPrice2 { get; set; }
          public decimal? sellPrice2 { get; set; }
          public DateTime releasedate { get; set; }
          public decimal? Rate { get { return buyPrice1 / (currencyUnit ?? 100); } }
      }

     static void Main(string[] args)
      {
          string url = "http://data.bank.hexun.com/other/cms/foreignexchangejson.ashx";
          WebClient webClient = new WebClient();
          webClient.Credentials = CredentialCache.DefaultCredentials;//获取或设置用于向Internet资源的请求进行身份验证的网络凭据
          Byte[] pageData = webClient.DownloadData(url); //从指定网站下载数据
          string pageHtml = Encoding.Default.GetString(pageData);  //如果获取网站页面采用的是GB2312，则使用这句
          pageHtml = pageHtml.Replace("ForeignexchangeData(", "").Replace("])", "]");
          List<ExRate> dycs = JsonConvert.DeserializeObject<List<ExRate>>(pageHtml);
          var q =
          from p in dycs
          group p by new { p.code, p.currency } into g
          select new
          {
              g.Key,
              //这里是取几家银行的平均值 我不了解标准的算法是什么 了解的可以自行修改
              AveragePrice = g.Average(p => p.buyPrice1 / (p.currencyUnit ?? 100))
          };

         foreach (var item in q)
          {
              if (!string.IsNullOrEmpty(item.Key.code))
                  Console.WriteLine(item.Key.code + "\t" + item.Key.currency + "\t\t" + item.AveragePrice + "\r\n");
          }
          Console.Read();
      }
  }