[C#]Datatable和json互相转换操作

 #region  DataTable 转换为Json字符串实例方法
 /// <summary>
 /// GetClassTypeJosn 的摘要说明
 /// </summary>
 public class GetClassTypeJosn : IHttpHandler
 {
     /// <summary>
     /// 文件名:DataTable 和Json 字符串互转
     /// 版权所有:Copyright (C) Create Family Wealth liangjw
     /// 创建标示：2013-08-03
     /// </summary>
     //用法说明实例
      public void ProcessRequest(HttpContext context)
     {
         context.Response.ContentType = "application/json";
         context.Response.Charset = "utf-8";
         HttpRequest req = context.Request;
         string method = req["method"].ToStr().ToLower();

        //获取合同明细列表  DataTable 转换为Json字符串
         if (method == "txtdate")
         {
             string json = "";
             BO.MakeContractMx bll = new MakeContractMx();
             DataSet ds = bll.GetDataTable();
             if (ds.Tables.Count > )
             {
                 json =ToJson(ds.Tables[]);
             }
             context.Response.Write(json);
             return;
         }

     }

    public bool IsReusable
     {
         get
         {
             return false;
         }
     }
 }

    #endregion

     #region Json字符串转换为DataTable 实例方法

     public DataTable JsonToDataTable(json)
     {
        DataTable  dt= ToDataTable(json);
          return dt;
     }

    #endregion

     #region DataTable 转换为Json 字符串
     /// <summary>
     /// DataTable 对象 转换为Json 字符串
     /// </summary>
     /// <param name="dt"></param>
     /// <returns></returns>
     public static string ToJson(this DataTable dt)
     {
         JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();
         javaScriptSerializer.MaxJsonLength = Int32.MaxValue; //取得最大数值
         ArrayList arrayList = new ArrayList();
         foreach (DataRow dataRow in dt.Rows)
         {
             Dictionary<string, object> dictionary = new Dictionary<string, object>();  //实例化一个参数集合
             foreach (DataColumn dataColumn in dt.Columns)
             {
                 dictionary.Add(dataColumn.ColumnName, dataRow[dataColumn.ColumnName].ToStr());
             }
             arrayList.Add(dictionary); //ArrayList集合中添加键值
         }

         return javaScriptSerializer.Serialize(arrayList);  //返回一个json字符串
     }
     #endregion

     #region Json 字符串 转换为 DataTable数据集合
     /// <summary>
     /// Json 字符串 转换为 DataTable数据集合
     /// </summary>
     /// <param name="json"></param>
     /// <returns></returns>
     public static DataTable ToDataTable(this string json)
     {
         DataTable dataTable = new DataTable();  //实例化
         DataTable result;
         try
         {
             JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();
             javaScriptSerializer.MaxJsonLength = Int32.MaxValue; //取得最大数值
             ArrayList arrayList = javaScriptSerializer.Deserialize<ArrayList>(json);
             if (arrayList.Count > )
             {
                 foreach (Dictionary<string, object> dictionary in arrayList)
                 {
                     if (dictionary.Keys.Count<string>() == )
                     {
                         result = dataTable;
                         return result;
                     }
                     if (dataTable.Columns.Count == )
                     {
                         foreach (string current in dictionary.Keys)
                         {
                             dataTable.Columns.Add(current, dictionary[current].GetType());
                         }
                     }
                     DataRow dataRow = dataTable.NewRow();
                     foreach (string current in dictionary.Keys)
                     {
                         dataRow[current] = dictionary[current];
                     }

                     dataTable.Rows.Add(dataRow); //循环添加行到DataTable中
                 }
             }
         }
         catch
         {
         }
         result = dataTable;
         return result;
     }
     #endregion

     #region 转换为string字符串类型
     /// <summary>
     ///  转换为string字符串类型
     /// </summary>
     /// <param name="s">获取需要转换的值</param>
     /// <param name="format">需要格式化的位数</param>
     /// <returns>返回一个新的字符串</returns>
     public static string ToStr(this object s, string format = "")
     {
         string result = "";
         try
         {
             if (format == "")
             {
                 result = s.ToString();
             }
             else
             {
                 result = string.Format("{0:" + format + "}", s);
             }
         }
         catch
         {
         }
         return result;
     }
    #endregion