using System.Web.Script.Serialization;

protected void Page_Load(object sender,EventArgs e)

{

//构建json对象
stringjsonstring="[ {posid:'611',city:'成都市'}, {posid:'621',city:'上海市'}, {posid:'631',city:'重庆市'}, {posid:'641',city:'海口市'} ]";

//将json数据转换成Json数组
//
JavaScriptSerializer 需引用System.Web.Script.Serialization;
JsonData[] data =new JavaScriptSerializer().Deserialize<JsonData[]>(jsonstring);

//获取json数据中某个值
string str1 = data[1].posid;     // str1==“621”
string str2 = data[1].city;        // str2=="上海市"

//修改json数据中某个值
data[1].posid=“620”;

//获取json数据长度
int len = data.Length;

}


//构建json
public class JsonData
{

public string posid{get;set;}
public string name {get;set;}

}