<?xml version="1.0" encoding="utf-8"?>

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

     android:orientation="vertical"

     android:layout_width="fill_parent"

     android:layout_height="fill_parent"

     android:minWidth="25px"

     android:minHeight="25px">

     <ListView

         android:id="@android:id/list"

         android:layout_width="fill_parent"

         android:layout_height="wrap_content" />

 </LinearLayout>

 using System;

 using System.Net;

 using System.IO;

 using System.Json;

 using System.Linq;

 using System.Xml.Linq;

 using Android.App;

 using Android.Content;

 using Android.Runtime;

 using Android.Views;

 using Android.Widget;

 using Android.OS;

 namespace NetJsonList

 {

     [Activity(Label = "NetJsonList", MainLauncher = true, Icon = "@drawable/icon")]

     public class MainActivity : ListActivity

     {

         class Test : Java.Lang.Object

         {

             public string[] Results { get; set; }

         }

         Test t;

         protected override void OnCreate(Bundle bundle)

         {

             base.OnCreate(bundle);

             SetContentView(Resource.Layout.Main);

             LoadXamarin();

         }

         //重写该方法

         public override Java.Lang.Object OnRetainNonConfigurationInstance()

         {

             return t;

         }

         public void LoadXamarin()

         {

             t = LastNonConfigurationInstance as Test;

             ////判断是否存在之前的状态

             if (t != null)

             {

                 ListAdapter = new ArrayAdapter<string>(this, Resource.Id.listView1, t.Results);

             }

             else

             {

                 //JSON请求URL

                 string url = "http://192.168.1.2/Country/OaAreaByCountryId?countryId=21&pid=76";

                 /*

                  {"stats":1,"result":[{"pid":76,"id":77,"name":"丽水市","py":"L","items":[{"iskc":true,"ids":"","peisongurl":"","id":78,"name":"莲都区","py":"L"},{"iskc":true,"ids":"","peisongurl":"","id":79,"name":"龙泉市","py":"L"},{"iskc":true,"ids":"","peisongurl":"","id":80,"name":"青田县","py":"Q"},{"iskc":true,"ids":"","peisongurl":"","id":81,"name":"缙云县","py":"J"},{"iskc":true,"ids":"","peisongurl":"","id":82,"name":"遂昌县","py":"S"},{"iskc":true,"ids":"","peisongurl":"","id":83,"name":"松阳县","py":"S"},{"iskc":true,"ids":"","peisongurl":"","id":84,"name":"云和县","py":"Y"},{"iskc":true,"ids":"","peisongurl":"","id":85,"name":"庆元县","py":"Q"},{"iskc":true,"ids":"","peisongurl":"","id":241,"name":"景宁畲族自治县","py":"J"}]}]}

                  */

                 //创建一个请求

                 var httpReq = (HttpWebRequest)HttpWebRequest.Create(new Uri(url));

                 //获取响应

                 // var httpRes = (HttpWebResponse)httpReq.GetResponse();

                 //读取流文本

                 //string text = new StreamReader(httpRes.GetResponseStream()).ReadToEnd();

                 //将流中的基于文本的 JSON 反序列化为 JSON CLR 类型

                 //var text = (JsonObject)JsonObject.Load(httpRes.GetResponseStream());

                 //测试

                 //var result = new string[] { "1", "2", "3", "4" };

                 //返回包含 JsonObject 中的键的集合

                 //var result = text.Keys.ToList();

                 //适配列表 视图ListView控件id="@android:id/list"

                 //ListAdapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, result);

                 httpReq.BeginGetResponse(new AsyncCallback(ReadXamarin), httpReq);

             }

         }

         //异步回调方法

         public void ReadXamarin(IAsyncResult asyn)

         {

             var httpReq = (HttpWebRequest)asyn.AsyncState;

             //获取响应

             using (var httpRes = (HttpWebResponse)httpReq.EndGetResponse(asyn))

             {

                 //判断是否成功获取响应

                 if (httpRes.StatusCode == HttpStatusCode.OK)

                 {

                     //读取响应

                     //var text = new StreamReader(httpRes.GetResponseStream()).ReadToEnd();

                     var text = (JsonObject)JsonObject.Load(httpRes.GetResponseStream());

                     //返回包含 JsonObject 中的键的集合

                     var result = text.Keys.ToList();

                     //适配列表 视图ListView控件id="@android:id/list"

                     //ListAdapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, result);

                     //切换到UI线程，否则无法对控件进行操作

                     RunOnUiThread(() =>

                     {

                         ListAdapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, result);

                     });

                 }

             }

         }

     }

 }