将Table转换为Json(Jquery的Ajax方法读取)

1. 创建Users表 

 create table Users
 (
     UserId int identity(1,1) primary key,
     UserName varchar(20)
 )

 insert into Users values('Bradley')
 insert into Users values('Dan')

 

2. 创建JsonHelper类

 public class JsonHelper
    {
        #region  序列化和反序列化
        // 序列化
        public static  string JsonSerializer(T t)
        {
            // 使用 DataContractJsonSerializer 将 T 对象序列化为内存流。
            DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof (T));
            MemoryStream ms = new MemoryStream();
            // 使用 WriteObject 方法将 JSON 数据写入到流中。
            jsonSerializer.WriteObject(ms, t);
            // 流转字符串
            string jsonString = Encoding.UTF8.GetString(ms.ToArray());
            ms.Close();
            //替换Json的Date字符串
            string p = @"\\/Date\((\d+)\+\d+\)\\/";
            MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);
            Regex reg = new Regex(p);
            jsonString = reg.Replace(jsonString, matchEvaluator);
            return jsonString;
        }
        public static T JsonDeserialize(string  jsonString)
        {
            //将"yyyy-MM-dd HH:mm:ss"格式的字符串转为"\/Date(1294499956278+0800)\/"格式
            string p = @"\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}";
            MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertDateStringToJsonDate);
            Regex reg = new Regex(p);
            jsonString = reg.Replace(jsonString, matchEvaluator);
            DataContractJsonSerializer jsonSerializer=new DataContractJsonSerializer(typeof(T));
            // 字符串转流
            MemoryStream ms=new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
            // 通过使用 DataContractJsonSerializer 的 ReadObject 方法，将 JSON 编码数据反序列化为T
            T obj = (T) jsonSerializer.ReadObject(ms);
            return obj;
        }
        public static string ConvertJsonDateToDateString(Match match)
        {
            string result = string.Empty;
            DateTime dateTime=new DateTime(1970,1,1);
            dateTime = dateTime.AddMilliseconds(long.Parse(match.Groups[1].Value));
            dateTime = dateTime.ToLocalTime();
            result = dateTime.ToString("yyyy-MM-dd HH:mm:ss");
            return result;
        }
        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;
        }
        #endregion

        // 对象转换为Json
        public static  string  ObjectToJson(object obj)
        {
            JavaScriptSerializer js=new JavaScriptSerializer();
            try
            {
                return js.Serialize(obj);
            }
            catch (Exception exception)
            {

                throw new Exception(exception.Message);
            }
        }
        // 数据表转化为集合
        public static Liststring,object>> DataTableToList(DataTable dt)
        {
            Liststring ,object>> list=new Liststring, object>>();
            foreach (DataRow dataRow in dt.Rows)
            {
                Dictionary<string,object> dic=new Dictionary<string, object>();
                foreach (DataColumn dc in dt.Columns)
                {
                    dic.Add(dc.ColumnName,dataRow[dc.ColumnName]);
                }
                list.Add(dic);
            }
            return list;
        }
        // 表转换为Json
        public static string DataTableToJson(DataTable dt)
        {
            return ObjectToJson(DataTableToList(dt));
        }
    }

 3. 添加ashx代码文件

 public class GetData : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            if (context.Request["action"]=="display")
            {
                context.Response.Write(JsonHelper.DataTableToJson(GetAllUsers()));
            }
        }

        static SqlConnection conn = new SqlConnection("server=.;database=Test;uid=sa;pwd=123456");
        public static DataTable GetAllUsers()
        {
            string sql = "select * from users";
            SqlDataAdapter adapter = new SqlDataAdapter(sql, conn);
            DataTable dt = new DataTable();
            adapter.Fill(dt);
            return dt;
        }
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

 

4. 前端调用

 <html xmlns="http://www.w3.org/1999/xhtml" >
 <head runat="server">
     <title>title>
     <script src="js/jquery-1.6.js" type="text/javascript">script>
     <script type="text/javascript">
         $(function() {
             var options = {
                 type: 'post',
                 url: "/GetData.ashx",
                 dataType: "json",
                 data: { action: "display" },
                 success: function(data) {
                     var html = "UserIdUserName";
                     $.each(data, function(i, result) {
                         html += "<tr><td>" + result["UserId"] + "td><td>" + result["UserName"] + "td>tr>";
                     })
                     html += "table>";
                     $("#divData").html(html);
                 }
             };
             $.ajax(options);
         });
     script>
 head>
 <body>
     <form id="form1" runat="server">
     <div id="divData">

     div>
     form>
 body>
 html>

5. 效果图

 

6. 同样可以通过getJSON方法读取数据

 $.getJSON("/GetData.ashx",{ action: "display" },function(data) {
      var html = "UserIdUserName";
      $.each(data, function(i, result) {
          html += "<tr><td>" + result["UserId"] + "td><td>" + result["UserName"] + "td>tr>";
      })
      html += "table>";
      $("#divData").html(html);
      })