listview动态获取数据

 1 public class MainActivity extends Activity {

 3 private ListView listView;

 4 private ArrayList Person persons;

 5 private ListAdapter adapter;

 6 private Handler handler=null;

 7 //xml文件的网络地址

 8 final String path="http://192.168.5.10:8080/FileServer/person.xml";

 9 @SuppressLint("HandlerLeak")

10 protected void onCreate(Bundle savedInstanceState) {

11 super.onCreate(savedInstanceState);

12 setContentView(R.layout.main);

14 listView=(ListView) super.findViewById(R.id.listview);

15 //cache=new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/cache");

17 //开一条子线程加载网络数据

18 Runnable runnable=new Runnable()

20 public void run() 

22 try 

24 Thread.sleep(2000);

25 //xmlwebData解析网络中xml中的数据

26 persons=XmlwebData.getData(path);

27 //发送消息，并把persons结合对象传递过去

28 handler.sendMessage(handler.obtainMessage(0, persons));

29 } 

30 catch (InterruptedException e) 

32 e.printStackTrace();

35 };

37 try 

39 //开启线程

40 new Thread(runnable).start();

41 //handler与线程之间的通信及数据处理

42 handler=new Handler()

44 public void handleMessage(Message msg) 

46 if(msg.what==0)

48 //msg.obj是获取handler发送信息传来的数据

49 @SuppressWarnings("unchecked")

50 ArrayList Person person=(ArrayList Person ) msg.obj;

51 //给ListView绑定数据

52 BinderListData(person);

55 };

56 } 

57 catch (Exception e) 

59 e.printStackTrace();

63 //绑定数据

64 public void BinderListData(ArrayList Person person)

66 //创建adapter对象

67 adapter=new ListViewAdapter(R.layout.item,this,person);

68 //将Adapter绑定到listview中

69 listView.setAdapter(adapter);

72 }

2.从网络中获取xml文件并解析数据

 1 public class XmlwebData 

 4 private static ArrayList Person persons=null; 6 public static ArrayList Person getData(final String path)

 8 try 

10 URL url=new URL(path);

11 Person person=null;


13 HttpURLConnection conn=(HttpURLConnection) url.openConnection();

14 conn.setRequestMethod("GET");

15 conn.setConnectTimeout(5000);

16 if(conn.getResponseCode()==200)

18 InputStream inputstream=conn.getInputStream(); 

21 XmlPullParser xml=Xml.newPullParser();

22 xml.setInput(inputstream, "UTF-8");

23 int event=xml.getEventType();

25 while(event!=XmlPullParser.END_DOCUMENT)

27 switch (event) 

29 //开始解析文档

30 case XmlPullParser.START_DOCUMENT:

31 persons=new ArrayList Person ();

32 break;

33 case XmlPullParser.START_TAG:

35 String value=xml.getName();

36 if(value.equals("person"))

37 {//person对象的初始化必须在这里初始化不然可能出现为null的现象

38 person=new Person();

39 //获取属性值

40 person.setId(new Integer(xml.getAttributeValue(0)));

42 else if(value.equals("name"))

44 person.setName(xml.nextText());

46 else if(value.equals("sex"))

48 person.setSex(xml.nextText());

50 else if(value.equals("age"))

52 person.setAge(new Integer(xml.nextText()));

54 else if(value.equals("path"))

56 person.setPath(xml.nextText());

58 break;

59 case XmlPullParser.END_TAG:

60 if(xml.getName().equals("person"))

62 persons.add(person);

63 System.out.println(person.getName());;

64 person=null;

66 break;

68 //解析下一个对象

69 event=xml.next();

71 return persons;

73 } 

74 catch (Exception e) 

76 e.printStackTrace();

77 } 

80 return null;

84 }

3.Person对象类

 1 public class Person 

 3 private int id;

 4 private String name;

 5 private String sex;

 6 private String path;

 7 public String getPath() {

 8 return path;

10 public void setPath(String path) {

11 this.path = path;

13 private int age;

14 public int getId() {

15 return id;

17 public void setId(int id) {

18 this.id = id;

20 public String getName() {

21 return name;

23 public void setName(String name) {

24 this.name = name;

26 public String getSex() {

27 return sex;

29 public void setSex(String sex) {

30 this.sex = sex;

32 public int getAge() {

33 return age;

35 public void setAge(int age) {

36 this.age = age;

38 public Person(){

41 }

4.Adapter数据适配器类

 1 public class ListViewAdapter extends BaseAdapter implements ListAdapter 

 4 private ArrayList Person data;

 5 private int id;

 6 private Context context;

 7 private LayoutInflater inflater;

 8 public ListViewAdapter(int item, MainActivity mainActivity,ArrayList Person data) 

10 this.data=data;

11 this.context=mainActivity;

12 this.id=item;

13 inflater=LayoutInflater.from(context);

16 @Override

17 public int getCount() 

19 return data.size();

22 @Override

23 public Object getItem(int position) 

25 return data.get(position);

28 @Override

29 public long getItemId(int position)

31 return position;

34 @Override

35 public View getView(int position, View view, ViewGroup arg2)

37 TextView name=null;

38 TextView sex=null;

39 TextView age=null;

40 ImageView img=null;

41 if(view==null)

43 view=inflater.inflate(id, null);

44 name=(TextView) view.findViewById(R.id.PersonName);

45 sex=(TextView) view.findViewById(R.id.PersonSex);

46 age=(TextView) view.findViewById(R.id.PersonAge);

47 img=(ImageView) view.findViewById(R.id.Personimage);

48 //保存view对象到ObjectClass类中

49 view.setTag(new ObjectClass(name,sex,age,img));

51 else

53 //得到保存的对象

54 ObjectClass object "性别："+person.getSex().toString());

65 age.setText("年龄："+String.valueOf(person.getAge()));

66 //加载图片资源

67 LoadImage(img,person.getPath());

68 return view;

72 private void LoadImage(ImageView img, String path) 

74 //异步加载图片资源

75 AsyncTaskImageLoad async=new AsyncTaskImageLoad(img);

76 //执行异步加载，并把图片的路径传送过去

77 async.execute(path);

81 private final class ObjectClass

83 TextView name=null;

84 TextView sex=null;

85 TextView age=null;

86 ImageView img=null;

87 public ObjectClass(TextView name, TextView sex, TextView age,ImageView img) 

89 this.name=name;

90 this.sex=sex;

91 this.age=age;

92 this.img=img;

97 }

5.异步加载图片类

 1 public class AsyncTaskImageLoad extends AsyncTask String, Integer, Bitmap {

 3 private ImageView Image=null;

 5 public AsyncTaskImageLoad(ImageView img) 

 7 Image=img;

 9 //运行在子线程中

10 protected Bitmap doInBackground(String... params) {

11 try 

13 URL url=new URL(params[0]);

14 HttpURLConnection conn=(HttpURLConnection) url.openConnection();

15 conn.setRequestMethod("POST");

16 conn.setConnectTimeout(5000);

17 if(conn.getResponseCode()==200)

19 InputStream input=conn.getInputStream();

20 Bitmap map=BitmapFactory.decodeStream(input);

21 return map;

23 } catch (Exception e) 

25 e.printStackTrace();

27 return null;

30 protected void onPostExecute(Bitmap result)

32 if(Image!=null result!=null)

34 Image.setImageBitmap(result);

37 super.onPostExecute(result);

39 }

6.网络中的person.xml文件内容为

 1 ?xml version="1.0" encoding="UTF-8"? 

 2 Persons 

 3 person id="1" 

 4 name 张三 /name 

 5 sex 男 /sex 

 6 age 25 /age 

 7 path http://192.168.5.10:8080/FileServer/chengjisihan.jpg /path 

 8 /person 

 9 person id="2" 

10 name 李斯 /name 

11 sex 男 /sex 

12 age 78 /age 

13 path http://192.168.5.10:8080/FileServer/laozi.jpg /path 

14 /person 

15 person id="3" 

16 name 王五 /name 

17 sex 男 /sex 

18 age 22 /age 

19 path http://192.168.5.10:8080/FileServer/lilongji.jpg /path 

20 /person 

21 person id="4" 

22 name 庞聪 /name 

23 sex 男 /sex 

24 age 31 /age 

25 path http://192.168.5.10:8080/FileServer/lishimin.jpg /path 

26 /person 

27 person id="5" 

28 name 孙膑 /name 

29 sex 男 /sex 

30 age 48 /age 

31 path http://192.168.5.10:8080/FileServer/lisi.jpg /path 

32 /person 

33 person id="6" 

34 name 孙武 /name 

35 sex 男 /sex 

36 age 58 /age 

37 path http://192.168.5.10:8080/FileServer/liyuan.jpg /path 

38 /person 

40 person id="7" 

41 name 成吉思汗 /name 

42 sex 男 /sex 

43 age 40 /age 

44 path http://192.168.5.10:8080/FileServer/sunbiin.jpg /path 

45 /person 

47 person id="8" 

48 name 李渊 /name 

49 sex 男 /sex 

50 age 36 /age 

51 path http://192.168.5.10:8080/FileServer/sunwu.jpg /path 

52 /person 

54 person id="9" 

55 name 李隆基 /name 

56 sex 男 /sex 

57 age 32 /age 

58 path http://192.168.5.10:8080/FileServer/wangwu.jpg /path 

59 /person 

60 person id="10" 

61 name 武则天 /name 

62 sex 女 /sex 

63 age 55 /age 

64 path http://192.168.5.10:8080/FileServer/wuzetian.jpg /path 

65 /person 

66 /Persons 

运行结果如下

 

更高效地刷新 RecyclerView | DiffUtil二次封装 每次数据变化都全量刷新整个列表是很奢侈的，不仅整个列表会闪烁一下，而且所有可见表项都会重新绑定一遍数据。这一篇对 DiffUtil 进行二次封装以让其更易于使用。
更好的 RecyclerView 表项子控件点击监听器 上篇介绍了一种新的监听 RecyclerView 表项点击事件的方法。实现了将点击事件和RecyclerView.Adapter解耦。这一篇介绍如何监听 RecyclerView 表项子控件点击事件。