<form name="citydayform"
                                    action="http://datacenter.mep.gov.cn:80/report/air_daily/airDairyCityHour.jsp"
                                    method="post" style="margin: 0px auto 0px auto;"
                                    onsubmit="return checkForm1();">
                                    <table width="95%" border="1" align="center" cellpadding="0"
                                        cellspacing="0" bordercolorlight="#d9d7b2"
                                        bordercolordark="#ffffff" class="font">
                                        <tr>
                                            <td width="5%" height="30" bgcolor="#FFFFEF" align="right"
                                                class="STYLE1">
                                                城市:
                                            </td>
                                            <td width="8%" bgcolor="#FFFFFF">
                                                &nbsp;
                                                <input type="text" name=‘city‘ value="" />
                                            </td>
                                            <td width="5%" height="30" bgcolor="#FFFFEF" align="right"
                                                class="STYLE1 STYLE1">
                                                时间:
                                            </td>
                                            <td width="30%" bgcolor="#FFFFFF">
                                                &nbsp; 从:
                                                <input type="text" id="startdate" name="startdate"
                                                    readonly="true"
                                                    onfocus="WdatePicker({ el: this.id, dateFmt: ‘yyyy-MM-dd HH:mm‘, skin: ‘whyGreen‘,maxDate:‘#F{$dp.$D(\‘enddate\‘)}‘ })"
                                                    style="text-align: center;cursor: pointer;width: 160px;height: 21px;margin-top:0px;" class="Wdate"  value="2015-04-16 22:00" />
                                                到:
                                                <input type="text" id="enddate" name="enddate"
                                                    readonly="true"
                                                    onfocus="WdatePicker({ el: this.id, dateFmt: ‘yyyy-MM-dd HH:mm‘, skin: ‘whyGreen‘,minDate:‘#F{$dp.$D(\‘startdate\‘)}‘ })"
                                                    style="text-align: center;cursor: pointer;width: 160px;height: 21px;margin-top:0px;"  class="Wdate" value="2015-04-16 22:00" />
                                            </td>
                                            <td width="8%" bgcolor="#FFFFFF">
                                                <div align="center">
                                                    <input type="image" src="/report/main/images/search.gif"
                                                        width="83" height="19" />
                                                </div>
                                            </td>
                                        </tr>
                                    </table>
                                </form>

public partial class AirQuality
    {
        public int Id { get; set; }
        public System.DateTime Time { get; set; }
        public int AQI { get; set; }
        public int CityCode { get; set; }
        public string Level { get; set; }
        public string PrimaryPollutant { get; set; }
    }

while (true)
                {
                    string param = string.Format("city=&startdate={0}&enddate={1}&page={2}", lastGrabHBTime.AddHours(1).ToString("yyyy-MM-dd HH:mm"), currentTime.ToString("yyyy-MM-dd HH:mm"), pageIndex);
                    #region 数据抓取
                    while (true)
                    {
                        try
                        {
                            res = HttpHelper.PostRequest(Constant.HBUrl, param, Encoding.GetEncoding("GB2312"));
                            break;
                        }
                        catch (Exception)
                        {
                            Thread.Sleep(1000);
                        }
                    }
                    #endregion
                    res = Regex.Replace(res, "[\r\n|\t]", "").Replace(" ", " ");
                    var matches = regex.Matches(res);
                    if (matches.Count == 0)
                        break;
                    foreach (Match match in matches)
                    {
                        var group = match.Groups;
                        if (group.Count == 10)
                        {
                            var air = new AirQuality()
                            {
                                Time = DateTime.Parse(group[3].Value),
                                AQI = int.Parse(group[5].Value),
                                Level = group[7].Value,
                                PrimaryPollutant = group[9].Value,
                                CityCode = cityConfigs.FirstOrDefault(p => p.City == group[1].Value).Code
                            };
                            airQualities.Add(air);
                        }
                    }
                    pageIndex++;
                    Thread.Sleep(100);
                }

public static string PostRequest(string url, string param, string cookie = "")
        {
            return PostRequest(url, param, Encoding.UTF8, cookie);
        }
        public static string PostRequest(string url, string param, Encoding encoding, string cookie = "")
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(new Uri(url));
            request.ContentType = "application/x-www-form-urlencoded";
            request.UserAgent = "Mozilla/5.0 (MSIE 9.0; Windows NT 6.3; WOW64; Trident/7.0; rv:11.0) like Gecko";
            request.Method = "post";
            request.Timeout = 30000;
            request.KeepAlive = false;
            if (!string.IsNullOrEmpty(cookie))
            {
                request.Headers[HttpRequestHeader.Cookie] = cookie;
            }
            byte[] bytes = encoding.GetBytes(param);
            request.ContentLength = bytes.Length;
            using (Stream stream = request.GetRequestStream())
            {
                stream.Write(bytes, 0, bytes.Length);
            }
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            using (Stream stream = response.GetResponseStream())
            {
                StreamReader reader = new StreamReader(stream, encoding);
                return reader.ReadToEnd();
            }
        }