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[ASP.net教程].net 实体类与json转换(.net自带类库实现)更新


上一篇文章中写到在.net中实体类跟json格式的相互转换,今天在做具体转换时候,发现之前版本的jsonhelp对于日期类型的转换不全面。之前版本的jsonhelp中从实体类转换成json格式时候,将日期格式转成了时间戳的形式。在这里对这个jsonhelp做出了更新。以解决转换日期类型字段的问题。代码如下:

JsonHelp.cs

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Runtime.Serialization.Json;using System.IO;using System.Text.RegularExpressions;namespace JsonTest{  class JsonHelp  {    public JsonHelp()    {      //      // TODO: Add constructor logic here      //    }    /// <summary>    /// 把对象序列化 JSON 字符串     /// </summary>    /// <typeparam name="T">对象类型</typeparam>    /// <param name="obj">对象实体</param>    /// <returns>JSON字符串</returns>    public static string GetJson<T>(T obj)    {      //记住 添加引用 System.ServiceModel.Web       /**       * 如果不添加上面的引用,System.Runtime.Serialization.Json; Json是出不来的哦       * */      DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(T));      using (MemoryStream ms = new MemoryStream())      {        json.WriteObject(ms, obj);        string jsonString = Encoding.UTF8.GetString(ms.ToArray());        string pattern = @"\\/Date\((\d+)\+\d+\)\\/";        MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);        Regex reg = new Regex(pattern);        jsonString = reg.Replace(jsonString, matchEvaluator);        return jsonString;      }    }    /// <summary>    /// 把JSON字符串还原为对象    /// </summary>    /// <typeparam name="T">对象类型</typeparam>    /// <param name="jsonString">JSON字符串</param>    /// <returns>对象实体</returns>    public static T ParseFormJson<T>(string jsonString)    {      T obj = Activator.CreateInstance<T>();      string pattern = @"\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}";      MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertDateStringToJsonDate);      Regex reg = new Regex(pattern);      jsonString = reg.Replace(jsonString, matchEvaluator);      using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))      {        DataContractJsonSerializer dcj = new DataContractJsonSerializer(typeof(T));        return (T)dcj.ReadObject(ms);      }    }    /// <summary>    /// 将Json序列化的时间由/Date(1304931520336+0800)/转为字符串    /// </summary>    private static string ConvertJsonDateToDateString(Match m)    {      string result = string.Empty;      DateTime dt = new DateTime(1970, 1, 1);      dt = dt.AddMilliseconds(long.Parse(m.Groups[1].Value));      dt = dt.ToLocalTime();      result = dt.ToString("yyyy-MM-dd HH:mm:ss");      return result;    }    /// <summary>    /// 将时间字符串转为Json时间    /// </summary>    private static string ConvertDateStringToJsonDate(Match m)    {      string result = string.Empty;      DateTime dt = DateTime.Parse(m.Groups[0].Value);      dt = dt.ToUniversalTime();      TimeSpan ts = dt - DateTime.Parse("1970-01-01");      result = string.Format("\\/Date({0}+0800)\\/", ts.TotalMilliseconds);      return result;    }  }}

测试代码:

using ConsoleApplication1.Models;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApplication1{  class Program  {    static void Main(string[] args)    {      using (var db = new JooWMSContext())       {        var admin = db.Admins.Where(p => p.ID > 0).OrderBy(p => p.ID);        foreach (var ad in admin)         {          Console.WriteLine(JsonTest.JsonHelp.GetJson<ConsoleApplication1.Models.Admin>(ad));        }        Console.ReadKey();      }    }  }}

写测试代码时候 用到了EF ,这里推荐一个不错的工具。EF Power Tools 目前是beta4 版本。