JsonHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using Newtonsoft.Json;
using System.Text;
using System.IO;
using System.Reflection;

/// <summary>
///JsonHelper 的摘要说明
/// </summary>
public class JsonHelper
{
    public JsonHelper()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }

    /// <summary>
    /// 将表的数据序列化为JSON串
    /// </summary>
    /// <param name="dt"></param>
    /// <param name="dtName"></param>
    /// <returns></returns>
    public static string DataTableToJSON(DataTable dt, string dtName)
    {
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);

        using (JsonWriter jw = new JsonTextWriter(sw))
        {
            JsonSerializer ser = new JsonSerializer();
            jw.WriteStartObject();
            jw.WritePropertyName(dtName);
            jw.WriteStartArray();
            foreach (DataRow dr in dt.Rows)
            {
                jw.WriteStartObject();

                foreach (DataColumn dc in dt.Columns)
                {
                    jw.WritePropertyName(dc.ColumnName);
                    ser.Serialize(jw, dr[dc].ToString());
                
                }

                jw.WriteEndObject();
            }
            jw.WriteEndArray();
            jw.WriteEndObject();

            sw.Close();
            jw.Close();

        }

        return sb.ToString();
    }

    /// <summary>
    /// 将对象序列化为JSON串
    /// </summary>
    /// <typeparam name="T">对象的数据类型</typeparam>
    /// <param name="obj">对象</param>
    /// <returns>JSON串</returns>
    public static string ObjectToJSON<T>(T obj)
    {
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);

        using (JsonWriter jw = new JsonTextWriter(sw))
        {
            JsonSerializer ser = new JsonSerializer();
            jw.WriteStartObject();
            T o = Activator.CreateInstance<T>();
            PropertyInfo[] pi = o.GetType().GetProperties();

            foreach (PropertyInfo p in pi)
            {
                jw.WritePropertyName(p.Name);
                var values = p.GetValue(obj, null);
                ser.Serialize(jw, p.GetValue(obj, null));
            }
            jw.WriteEndObject();

            sw.Close();
            jw.Close();
        }

        string a = sb.ToString();
        return sb.ToString();
    }

    /// <summary>
    /// 将集合序列化为JSON串
    /// </summary>
    /// <typeparam name="T">集合中的对象的数据类型</typeparam>
    /// <param name="obj">对象</param>
    /// <returns>JSON串</returns>

    /// <summary>
    /// 将集合序列化为JSON串
    /// </summary>
    /// <typeparam name="T">集合中的对象的数据类型</typeparam>
    /// <param name="list">泛型集合</param>
    /// <param name="jsonName">集合对象的名称</param>
    /// <returns>JSON串</returns>
    public static string ListToJSON<T>(IList<T> list, string jsonName)
    {
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);

        using (JsonWriter jw = new JsonTextWriter(sw))
        {
            JsonSerializer ser = new JsonSerializer();
            jw.WriteStartObject();
            jw.WritePropertyName(jsonName);
            jw.WriteStartArray();
           

            if (list.Count > 0)
            {
                for (int i = 0; i < list.Count; i++)
                {
                    jw.WriteStartObject();

                    T obj = Activator.CreateInstance<T>();
                    PropertyInfo[] pi = obj.GetType().GetProperties();

                    foreach (PropertyInfo p in pi)
                    {
                        jw.WritePropertyName(p.Name);
                    
                        ser.Serialize(jw, p.GetValue(list[i], null));
                     
                    }

                    jw.WriteEndObject();
                }
            }

            jw.WriteEndArray();
            jw.WriteEndObject();

            sw.Close();
            jw.Close();

        }

        return sb.ToString();
    }
}