using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Linq;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json;

using System.IO;

using System.Net;

public partial class _Default : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        string str = "{'a':'aaa','b':'bbb','c':'ccc'}";

        JObject jo = JObject.Parse(str);

        if (jo.Property("a") == null || jo.Property("").ToString() == "")

        {

            Label1.Text = "键值key不存在！";

        }

        IEnumerable<JProperty> properties = jo.Properties();

        foreach (JProperty item in properties)

        {

            Label2.Text += item.Name + ":" + item.Value;

        }

        Label3.Text = jo.Value<string>("a");

    }

}