Android之ListView&Json加载网络数据

使用到的主要内容：

1、Json 解析网络数据

2、异步任务加载图片和数据

3、ListView 的内存空间优化（ConvertView）和运行时间优化（ViewHolder）

4、ListView 滚动监听实现分页加载数据

5、动态定义 布局和控件（想实现下拉刷新，好像不是这样实现的..）

　　.......

HttpUtil 工具类网络申请数据（用 Gson 解析）

--- 别忘记添加网络权限

<uses-permission android:name="android.permission.INTERNET"/>

 package com.dragon.android.a09_09;

 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;

 /**
  * Created by Auser on 2016/9/7.
  */
 public class HttpUtil {

     public static byte[] loadByte(String url){

         HttpURLConnection conn = null;
         InputStream is = null;
         ByteArrayOutputStream baos = null;
         try {
             conn = (HttpURLConnection) new URL(url).openConnection();
             if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                 is = conn.getInputStream();
                 baos = new ByteArrayOutputStream();

                 byte[] buffer = new byte[1024];
                 int len = -1;
                 while ((len = is.read(buffer)) != -1) {
                     baos.write(buffer,0,len);
                 }
                 return baos.toByteArray();
             }
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             try {
                 if (baos!=null){
                     baos.flush();
                     baos.close();
                 }
                 if (is != null) {
                     is.close();
                 }
                 if (conn != null) {
                     conn.disconnect();
                 }
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return null;
     }

 }

HttpUtil

Datas 类存放需要的数据（GsonFormat 插件）

 package com.dragon.android.a09_09;

 import java.util.List;

 /**
  * Created by Auser on 2016/9/9.
  */
 public class Datas {

     /**
      * code : 99999
      * data : {"results":[{"action":0,"actionTime":1472219620657,"candidateCount":85,"caterAvgPrice":"49","caterBranchName":"中心城店","caterBusinessId":"DZ:2213221","caterCategories":"电影院","caterCity":"深圳","caterPhotoUrl":"http://qcloud.dpfile.com/pc/EXgo-1x_xBtU9ZucqX7hTSvd27a8ZWYntDVUaMciJtZbnpM9T49yMmnt4yPiPxuwTYGVDmosZWTLal1WbWRW3A.jpg","caterPlatform":1,"caterRegions":"福田区 市中心区","caterSPhotoUrl":"http://qcloud.dpfile.com/pc/EXgo-1x_xBtU9ZucqX7hTSvd27a8ZWYntDVUaMciJtZwpuORpFhuvgx7Yzr27-sHTYGVDmosZWTLal1WbWRW3A.jpg","caterShopId":382401,"caterTelephone":"0755-82801168","clientStamp":1472219156,"commentCount":201,"createTime":1472219620657,"credit":0,"deviceModel":"iPhone","eventAddress":"福田区福华一路怡景中心城G层","eventCity":"0755","eventCityName":"深圳","eventDateTime":1473420600000,"eventDescription":"简介：\n对于不会说人话情商低，公主病的，\n满嘴脏话，不懂得做人做事的，\n没时间更没兴趣撩你，套路你。\n吃瓜群众别瞎BB，东北人没那么好的脾气，\n会开玩笑的开，开的起玩笑的开，别装逼，\n长得好看你是优势，毕竟是个看脸的时代，\n但你没素质没礼貌就别老自以为自己很美。\n人丑不可怕，就怕你心也丑，做好你自己。\n每个人都差钱，谁也不是银行，但你别差事。\n做人都是相互的，你帮帮我我帮帮你，\n但别觉得一切都是理所当然的。\n能做兄弟做兄弟，能做朋友做朋友，爽快人\n别磨叽。\n\n确定艺人：汪涵，林志颖、任贤齐、\n                  萧亚轩、潘玮柏、李荣浩。\n\n待定艺人：许巍","eventExpense":47,"eventKey":"LFCAEL","eventLatitude":22.53608,"eventLocation":"金逸影城","eventLocationUrl":"http://m.dianping.com/shop/2213221?utm_source=open","eventLongitude":114.05923,"eventName":"有趣的灵魂一起去大运体育中心看演唱会","eventRegion":"福田区 市中心区","fee":1,"feeType":{"desc":"我请客","field":"MyTreat","value":1},"guarantee":0,"id":827518,"isMark":false,"multi":0,"opposite":0,"rechargeCred":0,"score":653.0702748285551,"showCount":3670,"state":0,"tagId":"3706","url":"http://www.qingchifan.com/event/detail/827518","user":{"action":1,"age":77,"constellation":"双鱼座","gender":1,"height":180,"isOfficial":"0","lastOnlineTime":"1473358886081","lat":22.54983991655006,"lng":114.1008416972523,"nick":"Mr.Yang","role2":"0","userId":127891,"userImageUrl":"http://img2.chouti.com/QIM/2016090901/7dff30c8e35047fda84bec83128af793.jpg","userKey":"EFCLME"},"userId":127891,"visitorState":0},{"action":0,"actionTime":1473378002766,"candidateCount":1,"caterAvgPrice":"288","caterBranchName":"","caterBusinessId":"DZ:2810071","caterCategories":"自助餐","caterCity":"深圳","caterPhotoUrl":"http://qcloud.dpfile.com/pc/ka5nJiUVP1iEDEInm-5ctFhAg0oTJ6h_JrWwPWyTVSvV-Oie0zXWa0hU-eqGUQgMTYGVDmosZWTLal1WbWRW3A.jpg","caterPlatform":1,"caterRegions":"福田区 市中心区","caterSPhotoUrl":"http://qcloud.dpfile.com/pc/ka5nJiUVP1iEDEInm-5ctFhAg0oTJ6h_JrWwPWyTVSsJDGuWFTd4kmkKP90dcyjBTYGVDmosZWTLal1WbWRW3A.jpg","caterShopId":74869,"caterTelephone":"0755-21513838","clientStamp":1473378002086,"commentCount":5,"createTime":1473378002766,"credit":130,"deviceModel":"Android","eventAddress":"福田区益田路4088号香格里拉大酒店1楼","eventCity":"0755","eventCityName":"深圳","eventDateTime":1474362000000,"eventDescription":"人品是当今社会稀缺而珍贵的品质标签，人品决定态度，态度决定行为，行为决定着最后的结果。女人外表漂亮固然惹人喜爱，但智慧以及谦卑的态度也不可缺少，否则，人就很容易显出骄傲自大、爱慕虚荣等丑恶的特质。","eventExpense":288,"eventKey":"LGLLED","eventLatitude":22.536156,"eventLocation":"福田香格里拉大酒店－鲜咖啡自助餐厅","eventLocationUrl":"http://m.dianping.com/shop/2810071?utm_source=open","eventLongitude":114.057,"eventName":"Buffet\n自助餐","eventRegion":"市中心区","fee":1,"feeType":{"desc":"我请客","field":"MyTreat","value":1},"guarantee":0,"guaranteeCred":0,"id":838810,"isMark":false,"multi":0,"opposite":2,"rechargeCred":0,"score":510.20296508423274,"showCount":22,"state":0,"tagId":"3792","url":"http://www.qingchifan.com/event/detail/838810","user":{"action":1,"age":28,"constellation":"白羊座","gender":1,"height":170,"isOfficial":"0","lastOnlineTime":"1473382864509","lat":22.650712,"lng":114.024987,"nick":"梦卧客","role2":"0","userId":35965,"userImageUrl":"http://img2.chouti.com/group/2016082810/1942adb39d8b69a37fa0887fd55bab9b.jpg","userKey":"GAMBA"},"userId":35965,"visitorState":0},{"action":0,"actionTime":1472372122903,"candidateCount":76,"caterAvgPrice":"366","caterBranchName":"深圳华侨城店","caterBusinessId":"DZ:2723608","caterCategories":"牛排 西餐","caterCity":"深圳","caterPhotoUrl":"http://i3.s2.dpfile.com/pc/f14584fdd425d9a5a70f747f7ebcc6fa(700x700)/thumb.jpg","caterPlatform":1,"caterRegions":"南山区 华侨城 白石洲 益田假日","caterSPhotoUrl":"http://i2.s2.dpfile.com/pc/f14584fdd425d9a5a70f747f7ebcc6fa(278x200)/thumb.jpg","caterShopId":1120,"caterTelephone":"0755-86298729","clientStamp":1472372124606,"commentCount":55,"createTime":1472372122903,"credit":0,"deviceModel":"Android","eventAddress":"南山区深南大道9028号益田假日广场3F","eventCity":"0755","eventCityName":"深圳","eventDateTime":1473417000000,"eventDescription":"一米八左右 干净利落不墨迹 有什么好玩的 求大神带我飞 随时都可以约 带我玩点新鲜的吧 报名了就来私啊