ASP.NET 复杂JSON字符串反序列化操作

在MIS系统开发中，有时需要在主页顶部显示天气信息，本篇经验将和大家介绍一下实现过程。

1、一个可以获取各个城市天气预报情况的网站：

http://wthrcdn.etouch.cn/weather_mini?city=合肥

参数city的值根据你所在的城市相应修改，获取到的气象信息如下图所示：

JSON字符串如下：

{    "desc": "OK",    "status": 1000,    "data": {        "wendu": "25",        "ganmao": "各项气象条件适宜，无明显降温过程，发生感冒机率较低。",        "forecast": [            {                "fengxiang": "南风",                "fengli": "3-4级",                "high": "高温 27℃",                "type": "晴",                "low": "低温 15℃",                "date": "14日星期五"            },            {                "fengxiang": "东风",                "fengli": "微风级",                "high": "高温 28℃",                "type": "多云",                "low": "低温 18℃",                "date": "15日星期六"            },            {                "fengxiang": "东南风",                "fengli": "3-4级",                "high": "高温 25℃",                "type": "中雨",                "low": "低温 16℃",                "date": "16日星期天"            },            {                "fengxiang": "西风",                "fengli": "3-4级",                "high": "高温 25℃",                "type": "多云",                "low": "低温 20℃",                "date": "17日星期一"            },            {                "fengxiang": "西北风",                "fengli": "3-4级",                "high": "高温 27℃",                "type": "晴",                "low": "低温 15℃",                "date": "18日星期二"            }        ],        "yesterday": {            "fl": "3-4级",            "fx": "南风",            "high": "高温 24℃",            "type": "晴",            "low": "低温 13℃",            "date": "13日星期四"        },        "aqi": "73",        "city": "合肥"    }}

附一个可以用于验证JSON字符串正确性的网址：http://www.bejson.com/

2、打开json2csharp网站，网站网址为：http://json2csharp.com/，将以上JSON串复制到编辑框中，然后点击“Generate”按钮，生成实体类，如下图所示：

3、C#代码实现，核心代码如下：

using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace CommonClass{    public class Forecast    {        public string fengxiang { get; set; }        public string fengli { get; set; }        public string high { get; set; }        public string type { get; set; }        public string low { get; set; }        public string date { get; set; }    }    public class Yesterday    {        public string fl { get; set; }        public string fx { get; set; }        public string high { get; set; }        public string type { get; set; }        public string low { get; set; }        public string date { get; set; }    }    public class Data    {        public string wendu { get; set; }        public string ganmao { get; set; }        public List<Forecast> forecast { get; set; }        public Yesterday yesterday { get; set; }        public string aqi { get; set; }        public string city { get; set; }    }    public class RootObject    {        public string desc { get; set; }        public int status { get; set; }        public Data data { get; set; }    }}

Json2Entities.cs代码如下：

using System;using System.Collections.Generic;using System.IO;using System.Linq;using System.Runtime.Serialization.Json;using System.Text;using System.Web;namespace CommonClass{    public class Json2Entities    {        /// <summary>          /// 将json字符串转化为方法实体类          /// </summary>          /// <typeparam name="T"></typeparam>          /// <param name="jsonString"></param>          /// <returns></returns>          public static T JsonToObject<T>(string jsonString)        {            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));            T jsonObject = (T)ser.ReadObject(ms);            ms.Close();            return jsonObject;        }    }}

        //用UTF-8转码有汉字参数的url        protected string UrlUtf_8(string url)        {            byte[] bs = Encoding.GetEncoding("UTF-8").GetBytes(url);            StringBuilder sb = new StringBuilder();            for (int i = 0; i < bs.Length; i++)            {                if (bs[i] < 128)                    sb.Append((char)bs[i]);                else                {                    sb.Append("%" + bs[i++].ToString("x").PadLeft(2, '0'));                    sb.Append("%" + bs[i].ToString("x").PadLeft(2, '0'));                }            }            return sb.ToString();        }        //用UrlGB2312转码有汉字参数的url        protected string UrlGB2312(string url)        {            byte[] bs = Encoding.GetEncoding("GB2312").GetBytes(url);            StringBuilder sb = new StringBuilder();            for (int i = 0; i < bs.Length; i++)            {                if (bs[i] < 128)                    sb.Append((char)bs[i]);                else                {                    sb.Append("%" + bs[i++].ToString("x").PadLeft(2, '0'));                    sb.Append("%" + bs[i].ToString("x").PadLeft(2, '0'));                }            }            return sb.ToString();        }        /// <summary>        ///         /// </summary>        /// <param name="url"></param>        /// <returns></returns>        public string GetFunction(string url)        {            string serviceAddress = url;            //HttpWebRequest类继承于WebRequest，并没有自己的构造函数，需通过WebRequest的Creat方法 建立，并进行强制的类型转换             HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);            request.ContentType = "text/html;charset=UTF-8";            request.Method = "GET";            //通过HttpWebRequest的GetResponse()方法建立HttpWebResponse,强制类型转换             HttpWebResponse response = (HttpWebResponse)request.GetResponse();            //GetResponseStream()方法获取HTTP响应的数据流,并尝试取得URL中所指定的网页内容             Stream myResponseStream = response.GetResponseStream();            //站点在响应的时候用gzip压缩过了,用using (var gStream = new GZipStream(myResponseStream, CompressionMode.Decompress)){}解压             using (var gStream = new GZipStream(myResponseStream, CompressionMode.Decompress))            {                //Encoding.GetEncoding("UTF-8")转码                StreamReader myStreamReader = new StreamReader(gStream, Encoding.GetEncoding("UTF-8"));                string retString = myStreamReader.ReadToEnd();                myStreamReader.Close();                response.Close();                myResponseStream.Close();                return retString;            }        }

string url = "http://wthrcdn.etouch.cn/weather_mini?city=合肥";string info = GetFunction(url);RootObject rootObj = new RootObject();rootObj = Json2Entities.JsonToObject<RootObject>(info);string weather = rootObj.data.city + " " + rootObj.data.forecast[0].type + " " + rootObj.data.forecast[0].low.Replace("低温", "") + " ~ " + rootObj.data.forecast[0].high.Replace("高温", "");

4、实现效果如下图所示：