網易新聞看起來很簡潔，左邊是一張圖片，右邊是一些文字信息，這樣的排版是十分常見的，給人的感覺就是簡潔明了，下面通過解析網絡json數據並展示到ListView上，來實現同樣的效果，效果圖如下：
1.數據來源於網上json數據的解析，網址為http://mrobot.pcauto.com.cn/v2/cms/channels/3?pageNo=1&pageSize=20&v=4.0.0（可能過段時間就失效了），如果想了解json解析或者獲取json數據接口，參照：http://blog.csdn.net/ljw124213/article/details/52313758。json的格式如下(這裡只解析title,image和pubDate三個字段)：
2.先寫出解析此json數據的實體類：
package com.example.listview;
import java.util.ArrayList;
public class CarBean {
public ArrayListdata;
public static class Car{
public String title;
public String pubDate;
public String image;
}
}
3.解析json數據的工具類：
package com.example.listview;
import com.google.gson.Gson;
public class JsonUtils {
public static CarBean parseJson(String jsonString){
Gson gson = new Gson();
CarBean cb = gson.fromJson(jsonString, CarBean.class);
return cb;
}
}
注意：使用Gson解析的話，必須先下載Gson的jar包，放到工程的libs目錄下，下載地址：http://download.csdn.net/detail/ljw124213/9612607
4.從網絡上下載數據的工具類：
package com.example.listview;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class NetUtils {
public static byte[] getNetData(String urlString){
try {
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setReadTimeout(5000);
conn.setConnectTimeout(5000);
byte[] result = null;
if (conn.getResponseCode() == 200) {
InputStream is = conn.getInputStream();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while((len=is.read(buffer))!=-1){
baos.write(buffer, 0, len);
}
result = baos.toByteArray();
}
return result;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
5.下載android-smart-image-view開源框架，把其src下的部分復制到自己工程的src下面，下載地址（帶有使用詳解）：http://download.csdn.net/detail/ljw124213/9630820
6.准備工作完成之後，下面開始實現具體功能，創建一個異步任務類，來下載網絡數據：
package com.example.listview;
import java.util.ArrayList;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;
import com.example.listview.CarBean.Car;
public class DownAsynctask extends AsyncTask{
ArrayListdata;
MyAdapter adapter;
Context context;
public DownAsynctask(ArrayList data, MyAdapter adapter, Context context) {
super();
this.data = data;
this.adapter = adapter;
this.context = context;
}
/*
* 當主線程中調用executeOnExecutor方法或execute方法時，會調用此方法
*/
@Override
protected byte[] doInBackground(String... params) {
//下載網絡數據
return NetUtils.getNetData(params[0]);
}
/*
* doInBackground方法執行之後會執行此方法，並把結果傳過來
*/
@Override
protected void onPostExecute(byte[] result) {
super.onPostExecute(result);
if (result != null) {
//把從網絡上獲取的byte類型的數據轉換為String字符串
String jsonString = new String(result);
//用json解析工具來解析該字符串數據
CarBean cb = JsonUtils.parseJson(jsonString);
//取出data數據，並保存到集合中
data.addAll(cb.data);
//刷新數據
adapter.notifyDataSetChanged();
}else {
Toast.makeText(context, "網絡異常", Toast.LENGTH_SHORT).show();
}
}
}
7.創建一個數據適配器，用來加載數據：
package com.example.listview;
import java.util.ArrayList;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.example.listview.CarBean.Car;
import com.loopj.android.image.SmartImageView;
public class MyAdapter extends BaseAdapter{
ArrayList data;
Context context;
public MyAdapter(ArrayList data, Context context) {
super();
this.data = data;
this.context = context;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return data.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
//初始化holder對象
ViewHold holder;
if(convertView == null){
//把條目布局轉化為view對象
convertView = View.inflate(context, R.layout.item, null);
//初始化holder對象，並初始化holder中的控件
holder = new ViewHold();
holder.tv_title = (TextView) convertView.findViewById(R.id.tv_title);
holder.tv_date = (TextView) convertView.findViewById(R.id.tv_date);
holder.iv = (SmartImageView) convertView.findViewById(R.id.iv);
//給當前view做個標記，並把數據存到該tag中
convertView.setTag(holder);
}else {
//如果當前view存在，則直接從中取出其保存的控件及數據
holder = (ViewHold) convertView.getTag();
}
//通過position獲取當前item的car數據，從car數據中取出title、pubDate和image
Car car = data.get(position);
holder.tv_title.setText(car.title);
holder.tv_date.setText(car.pubDate);
//使用SmartImageView的setImageUrl方法下載圖片
holder.iv.setImageUrl(car.image);
return convertView;
}
/*
* 用來存放item布局中控件的holder類
*/
class ViewHold{
SmartImageView iv; //顯示圖片的控件，注意是SmartImageView
TextView tv_title; //顯示標題的控件
TextView tv_date; //顯示日期的控件
}
}
8.在MainActivity中進行數據的匯總：
package com.example.listview;
import java.util.ArrayList;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;
import com.example.listview.CarBean.Car;
public class MainActivity extends Activity {
private ListView lv;
private ArrayList data;
private MyAdapter adapter;
private boolean flag = false;
private int pageNo = 1;
private ExecutorService es;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化listview控件
lv = (ListView) findViewById(R.id.lv);
//存放json解析的數據的集合
data = new ArrayList();
//自定義適配器
adapter = new MyAdapter(data,this);
//給listview設置一個底部view(必須在設置數據之前)
View footView = View.inflate(this, R.layout.foot, null);
lv.addFooterView(footView);
//給listview設置適配器
lv.setAdapter(adapter);
//使用線程池來實現異步任務的多線程下載
es = Executors.newFixedThreadPool(10);
new DownAsynctask(data,adapter,this).executeOnExecutor(es, "http://mrobot.pcauto.com.cn/v2/cms/channels/3?pageNo="+pageNo+"&pageSize=20&v=4.0.0");
/*
* 對listview設置滾動監聽事件，實現分頁加載數據
*/
lv.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
//如果停止了滑動且滑動到了結尾，則更新數據,加載下一頁
if (scrollState == OnScrollListener.SCROLL_STATE_IDLE && flag == true) {
pageNo += 1;
new DownAsynctask(data,adapter,MainActivity.this).executeOnExecutor(es, "http://mrobot.pcauto.com.cn/v2/cms/channels/3?pageNo="+pageNo+"&pageSize=20&v=4.0.0");
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
//判斷是否滑動到了結尾
if (firstVisibleItem + visibleItemCount == totalItemCount) {
flag = true;
}else {
flag = false;
}
}
});
}
}
9.ListView對應的布局文件activity_main.xml：
10.ListView對應的item的布局文件item.xml:
11.ListView尾布局對應的布局文件footer.xml:
提示：此數據接口可能很快就不能用來，如果需要測試的話，可以把原數據放到tomcat服務器中進行測試，下面是完整數據：
{
"data": [
{
"articleType": "n",
"count": 29,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/8/14733163729178590_600.jpg",
"id": "8562073",
"image": "http://img0.pcauto.com.cn/pcauto/1609/08/g_8562073_1473339813478_240x160.jpg",
"mtime": 1473351348000,
"pubDate": "2016-09-09",
"title": "新福特翼虎購車手冊 家用中配足夠實用",
"ups": 26,
"url": "http://www.pcauto.com.cn/teach/856/8562073.html"
},
{
"articleType": "n",
"count": 37,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1608/31/8655654_toutu_thumb.jpg",
"id": "8655654",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8655654_1472800030976_240x160.jpg",
"mtime": 1473351337000,
"pubDate": "2016-09-09",
"title": "年輕人第一台車 10萬左右精品車型推薦",
"ups": 130,
"url": "http://www.pcauto.com.cn/teach/865/8655654.html"
},
{
"articleType": "n",
"count": 35,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/06/8719572_toutu_thumb.jpg",
"id": "8719572",
"image": "http://img0.pcauto.com.cn/pcauto/1609/06/g_8719572_1473152785181_240x160.jpg",
"mtime": 1473264982000,
"pubDate": "2016-09-08",
"title": "豪門不“壕” 4款入門豪華SUV僅售23萬起",
"ups": 143,
"url": "http://www.pcauto.com.cn/teach/871/8719572.html"
},
{
"articleType": "n",
"count": 40,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/1/14727375445822660_600.jpg",
"id": "8705572",
"image": "http://img0.pcauto.com.cn/pcauto/1609/07/g_8705572_1473242245557_240x160.jpg",
"mtime": 1473264969000,
"pubDate": "2016-09-08",
"title": "明銳對比英朗 當歐洲紳士遇上美國大漢",
"ups": 52,
"url": "http://www.pcauto.com.cn/teach/870/8705572.html"
},
{
"articleType": "n",
"count": 68,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/6/14731526553913750_600.jpg",
"id": "8719262",
"image": "http://img0.pcauto.com.cn/pcauto/1609/06/g_8719262_1473151845818_240x160.jpg",
"mtime": 1473153591000,
"pubDate": "2016-09-06",
"title": "新晉英倫長軸距座駕 捷豹XFL實拍解析",
"ups": 299,
"url": "http://www.pcauto.com.cn/teach/871/8719262.html"
},
{
"articleType": "n",
"count": 100,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/07/8695292_999_thumb.jpg",
"id": "8695292",
"image": "http://img0.pcauto.com.cn/pcauto/1609/01/g_8695292_1472695974218_240x160.jpg",
"mtime": 1473137438000,
"pubDate": "2016-09-06",
"title": "15萬元搞定 四款獨立後懸掛合資SUV推薦",
"ups": 117,
"url": "http://www.pcauto.com.cn/teach/869/8695292.html"
},
{
"articleType": "n",
"count": 84,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/06/8718677_xin1000_thumb.jpg",
"id": "8718677",
"image": "http://img0.pcauto.com.cn/pcauto/1609/05/g_8718677_1473061488223_240x160.jpg",
"mtime": 1473092132000,
"pubDate": "2016-09-06",
"title": "8萬元選靠譜SUV 4款新推自主車型推薦",
"ups": 91,
"url": "http://www.pcauto.com.cn/teach/871/8718677.html"
},
{
"articleType": "n",
"count": 96,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20168/29/14724733055558460_600.jpg",
"id": "8683971",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8683971_1472803720871_240x160.jpg",
"mtime": 1473005791000,
"pubDate": "2016-09-05",
"title": "凱美瑞對比雅閣 誰才是日系中級車霸主",
"ups": 65,
"url": "http://www.pcauto.com.cn/teach/868/8683971.html"
},
{
"articleType": "n",
"count": 136,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/04/8716791_00_thumb.jpg",
"id": "8716791",
"image": "http://img0.pcauto.com.cn/pcauto/1609/04/g_8716791_1473002216143_240x160.jpg",
"mtime": 1473005746000,
"pubDate": "2016-09-05",
"title": "精華都在這裡 成都車展最值得關注的SUV",
"ups": 390,
"url": "http://www.pcauto.com.cn/teach/871/8716791.html"
},
{
"articleType": "n",
"count": 26,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/4/14729794978954170_600.jpg",
"id": "8716391",
"image": "http://img0.pcauto.com.cn/pcauto/1609/04/g_8716391_1472979896686_240x160.jpg",
"mtime": 1472980188000,
"pubDate": "2016-09-04",
"title": "2016成都車展：靜態評測奔馳新一代威霆",
"ups": 312,
"url": "http://www.pcauto.com.cn/teach/871/8716391.html"
},
{
"articleType": "n",
"count": 32,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/01/8700555_8207206_03_thumb.jpg",
"id": "8700555",
"image": "http://img0.pcauto.com.cn/pcauto/1609/01/g_8700555_1472716638381_240x160.jpg",
"mtime": 1472919329000,
"pubDate": "2016-09-04",
"title": "入門性價比爆炸 新款致炫購車手冊",
"ups": 91,
"url": "http://www.pcauto.com.cn/teach/870/8700555.html"
},
{
"articleType": "n",
"count": 70,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14728310541595730_600.jpg",
"id": "8712133",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8712133_1472831164431_240x160.jpg",
"mtime": 1472832200000,
"pubDate": "2016-09-03",
"title": "2016成都車展：靜態評測北京現代勝達",
"ups": 468,
"url": "http://www.pcauto.com.cn/teach/871/8712133.html"
},
{
"articleType": "n",
"count": 41,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/02/8710078_1000_thumb.jpg",
"id": "8710078",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8710078_1472810381352_240x160.jpg",
"mtime": 1472817162000,
"pubDate": "2016-09-02",
"title": "2016成都車展：靜態評測新款瑪莎拉蒂總裁",
"ups": 299,
"url": "http://www.pcauto.com.cn/teach/871/8710078.html"
},
{
"articleType": "n",
"count": 62,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14728116986128820_600.jpg",
"id": "8711094",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8711094_1472812405190_240x160.jpg",
"mtime": 1472812618000,
"pubDate": "2016-09-02",
"title": "2016成都車展：靜態評測大眾新桑塔納",
"ups": 1053,
"url": "http://www.pcauto.com.cn/teach/871/8711094.html"
},
{
"articleType": "n",
"count": 28,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14728073809221840_600.jpg",
"id": "8710334",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8710334_1472807999865_240x160.jpg",
"mtime": 1472808197000,
"pubDate": "2016-09-02",
"title": "2016成都車展：靜態體驗北京現代悅納",
"ups": 247,
"url": "http://www.pcauto.com.cn/teach/871/8710334.html"
},
{
"articleType": "n",
"count": 31,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14728054816668520_600.jpg",
"id": "8710116",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8710116_1472805803455_240x160.jpg",
"mtime": 1472806069000,
"pubDate": "2016-09-02",
"title": "2016成都車展：靜態評測東南DX3",
"ups": 247,
"url": "http://www.pcauto.com.cn/teach/871/8710116.html"
},
{
"articleType": "n",
"count": 60,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14728006933643890_600.jpg",
"id": "8709146",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8709146_1472801055169_240x160.jpg",
"mtime": 1472801551000,
"pubDate": "2016-09-02",
"title": "2016成都車展：靜態評測寶馬X1混動版",
"ups": 806,
"url": "http://www.pcauto.com.cn/teach/870/8709146.html"
},
{
"articleType": "n",
"count": 87,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14727918621883140_600.jpg",
"id": "8708181",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8708181_1472793809972_240x160.jpg",
"mtime": 1472794520000,
"pubDate": "2016-09-02",
"title": "2016成都車展：靜態評測東風本田競瑞",
"ups": 533,
"url": "http://www.pcauto.com.cn/teach/870/8708181.html"
},
{
"articleType": "n",
"count": 34,
"downs": 0,
"firstImg": "http://img0.pcauto.com.cn/pcauto/1609/02/8704693_toutu_thumb.jpg",
"id": "8704693",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8704693_1472787714022_240x160.jpg",
"mtime": 1472793542000,
"pubDate": "2016-09-02",
"title": "沖擊市場有力競爭者 新科沃茲購車手冊",
"ups": 117,
"url": "http://www.pcauto.com.cn/teach/870/8704693.html"
},
{
"articleType": "n",
"count": 111,
"downs": 0,
"firstImg": "http://img.pcauto.com.cn/images/pcautogallery/modle/article/20169/2/14727803654960920_600.jpg",
"id": "8706132",
"image": "http://img0.pcauto.com.cn/pcauto/1609/02/g_8706132_1472781925547_240x160.jpg",
"mtime": 1472781940000,
"pubDate": "2016-09-02",
"title": "7座對標漢蘭達 斯柯達KODIAQ實拍解析",
"ups": 104,
"url": "http://www.pcauto.com.cn/teach/870/8706132.html"
}
],
"pageNo": 1,
"pageSize": 20,
"total": 200
}
