json，DataTable，model

1、DataTable转json

public class DataTableConvertJson
    {

        #region dataTable转换成Json格式
        /// <summary>  
        /// dataTable转换成Json格式  
        /// </summary>  
        /// <param name="dt"></param>  
        /// <returns></returns>  
        public static string DataTable2Json(DataTable dt)
        {
            StringBuilder jsonBuilder = new StringBuilder();
            jsonBuilder.Append("{"");
            jsonBuilder.Append(dt.TableName);
            jsonBuilder.Append("":[");
            jsonBuilder.Append("[");
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                jsonBuilder.Append("{");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    jsonBuilder.Append(""");
                    jsonBuilder.Append(dt.Columns[j].ColumnName);
                    jsonBuilder.Append("":"");
                    jsonBuilder.Append(dt.Rows[i][j].ToString());
                    jsonBuilder.Append("",");
                }
                jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
                jsonBuilder.Append("},");
            }
            jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
            jsonBuilder.Append("]");
            jsonBuilder.Append("}");
            return jsonBuilder.ToString();
        }

        #endregion dataTable转换成Json格式
        #region DataSet转换成Json格式
        /// <summary>  
        /// DataSet转换成Json格式  
        /// </summary>  
        /// <param name="ds">DataSet</param> 
        /// <returns></returns>  
        public static string Dataset2Json(DataSet ds)
        {
            StringBuilder json = new StringBuilder();

            foreach (DataTable dt in ds.Tables)
            {
                json.Append("{"");
                json.Append(dt.TableName);
                json.Append("":");
                json.Append(DataTable2Json(dt));
                json.Append("}");
            } return json.ToString();
        }
        #endregion

        /// <summary>
        /// Msdn
        /// </summary>
        /// <param name="jsonName"></param>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string DataTableToJson(string jsonName, DataTable dt)
        {
            StringBuilder Json = new StringBuilder();
            Json.Append("{"" + jsonName + "":[");
            if (dt.Rows.Count > 0)
            {
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    Json.Append("{");
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        Json.Append(""" + dt.Columns[j].ColumnName.ToString() + "":"" + dt.Rows[i][j].ToString() + """);
                        if (j < dt.Columns.Count - 1)
                        {
                            Json.Append(",");
                        }
                    }
                    Json.Append("}");
                    if (i < dt.Rows.Count - 1)
                    {
                        Json.Append(",");
                    }
                }
            }
            Json.Append("]}");
            return Json.ToString();
        }
    }

调用  json=  DataTableConvertJson.DataTableToJson("tble", tblDatas);

//Quotation_No 为tblDatas的一列
 alert(msg.tble[i].Quotation_No)

2、对象转json

System.Runtime.Serialization.Json，杯具的孩子会发现，在添加引用里根本找不到此命名空间，找到的是System.Runtime.Serialization，添加引用后，根本不管用，此命名空间里根本不包括序列化要用到的对象DataContractJsonSerializer，那，这个对象到底在哪里呢。。。。经过不断的查终于找到了，这个坑爹的货藏的很深呀。正确的是直接添加这个引用 System.Servicemodel.Web就把问题解决了。

// using System.Runtime.Serialization.Json;

     <summary>
     解析JSON，仿Javascript风格
     </summary>
    public static class JSON
    {

        public static T parse<T>(string jsonString)
        {
            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))
            {
                return (T)new DataContractJsonSerializer(typeof(T)).ReadObject(ms);
            }
        }

        public static string stringify(object jsonObject)
        {
            using (var ms = new MemoryStream())
            {
                new DataContractJsonSerializer(jsonObject.GetType()).WriteObject(ms, jsonObject);
                return Encoding.UTF8.GetString(ms.ToArray());
            }
        }

　利用json.net

//Model转JSON
            Model m = new Model();
            m.city = "beijing";
            m.city_en = "北京";
            string json =   JsonConvert.SerializeObject(m);

//JSON转Model

　m= (Model)JsonConvert.DeserializeObject<Model>(str);