.net 之json 一般处理程序

<%@ WebHandler Language="C#" Class="read" %>

using System;
using System.Web;
using DBHelper;
using MySql.Data.MySqlClient;
using System.Web.SessionState;

public class read : IHttpHandler, IReadOnlySessionState
{

    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "text/plain";

            string sql = "select * from t_current_chat where client_guid= @client_guid";
            MySqlParameter[] pa = new MySqlParameter[] { new MySqlParameter("@client_guid", context.Session["guid"]) };
            MySqlDataReader dr = SqlHelper.ExecuteReaderText(sql, pa);

            System.Text.StringBuilder buf = new System.Text.StringBuilder("{");
            buf.Append("\"comments\":[");
            string names = "";
            while (dr.Read())
            {
                // names += "{\"client_guid\":\"" + dr["client_guid"].ToString() + "\"" + ",\"send_time\":\"" + dr["send_time"] + "\"" + ",\"chat_content\":\"" + dr["chat_content"].ToString() + "\"},";
                names += "{\"client_guid\":\"" + dr["client_guid"].ToString() + "\"" + ",\"send_time\":\"" + dr["send_time"].ToString() + "\"" + ",\"chat_content\":\"" + dr["chat_content"].ToString().Trim() + "\"},";
            }
            if (names != "")
            {
                names = names.Substring(0, names.Length - 1);
            }
            buf.Append(names);
            buf.Append("]}");
            context.Response.Write(buf.ToString());

    }

    public bool IsReusable {
        get {
            return false;
        }
    }

}