ListView的使用

MainActivity.java

 1 public class MainActivity extends ActionBarActivity {
 2 
 3     private ListView listView;
 4     //ArrayAdapter主要用于设置简单的数据格式如String
 5     private ArrayAdapter arr_Adapter;
 6     //SimpleAdapter主要用于设置复杂的数据
 7     private SimpleAdapter simp_Adapter;
 8     private List<Map<String,Object>> dataList;
 9 
10     @Override
11     protected void onCreate(Bundle savedInstanceState) {
12         super.onCreate(savedInstanceState);
13         setContentView(R.layout.activity_main);
14 
15         listView = (ListView)findViewById(R.id.listViewId);
16         //数据项内容
17         String[] arr = new String[]{"腾讯","360","QQ","迅雷","网易云音乐","安卓",
18                 "IOS","腾讯","360","QQ","迅雷","网易云音乐","安卓","IOS"};
19         /*/
20         context :上下文
21         resource ：Item的布局方式
22         objects ：数据项
23          */
24         arr_Adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,arr);
25 
26         dataList = new ArrayList<>();
27         /*/
28         context：上下文
29         java.util.List<? extends java.util.Map<java.lang.String, ?>> data：Adapter中的数据项
30         int resource：ListView的每个Item的布局文件
31         java.lang.String[] from：数据项中Map的键值
32         int[] to：将Map中的键值所对应的值对应到Item中的控件中
33          */
34         simp_Adapter = new SimpleAdapter(this,getDataList(),R.layout.item,new String[]{"picture","textView"},
35                 new int[]{R.id.pic,R.id.text});
36 
37         //listView.setAdapter(arr_Adapter);
38         listView.setAdapter(simp_Adapter);
39         listView.setOnItemClickListener(new ItemClickListener());
40         listView.setOnScrollListener(new ItemScrollListener());
41     }
42     //得到数据
43     public List<Map<String,Object>> getDataList(){
44 
45         for(int i = 0;i < 20;i++){
46             Map<String,Object> map = new HashMap<>();
47             map.put("picture",R.drawable.ic_launcher);
48             map.put("textView","Demo"+i);
49             dataList.add(map);
50         }
51         return dataList;
52     }
53 
54     class ItemClickListener implements AdapterView.OnItemClickListener{
55         @Override
56         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
57             //得到点击的Item对象
58             String str = listView.getItemAtPosition(position).toString();
59             Toast.makeText(MainActivity.this,str,Toast.LENGTH_SHORT).show();
60         }
61     }
62     //列表滚动的监听器
63     class ItemScrollListener implements AbsListView.OnScrollListener {
64         @Override
65         public void onScrollStateChanged(AbsListView view, int scrollState) {
66             switch (scrollState) {
67                 //当滑动列表松手后，列表通过惯性滑动的情况
68                 case SCROLL_STATE_FLING:
69                     Map<String,Object> map = new HashMap<>();
70                     map.put("picture",R.drawable.ic_launcher);
71                     map.put("textView","Demo");
72                     dataList.add(map);
73                     //通知主线程UI更新了
74                     simp_Adapter.notifyDataSetChanged();
75                     break;
76                 //当列表停止滑动时
77                 case SCROLL_STATE_IDLE:
78                     break;
79                 //当用手在滑动列表时
80                 case SCROLL_STATE_TOUCH_SCROLL:
81                     break;
82             }
83         }
84         @Override
85         public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
86 
87         }
88     }
89 }
ListView中的每个Item的布局item.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/pic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
        android:layout_marginLeft="5dp"/>

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="25sp"
        android:layout_gravity="center_vertical"
        android:text="文字"/>
</LinearLayout>

activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <ListView
        android:id="@+id/listViewId"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
    </ListView>

</RelativeLayout>