简单的android Listview使用例子

为了熟悉Listview的使用，做了一个小例子联系一下，
主要步骤：
1. 在MainActivity中，创建一个adapter对象（可以是android自带的ArrayAdapter，也可以是自定义的如SongAdapter）
2. 如果自定义，就要创建ListView的子项，如song_listview_item.xml
3. 创建ListView对象，并用setAdapter方法把adapter装进去
4. 用setOnItemClickListener设置点击事件

需要注意的是，在自定义的SongAdapter中最好能用convertView参数和一个缓存控件实例的类对象如ViewHolder来优化ListView的运行效率。
具体见源码

/*SongAdapter*/public class SongAdapter extends ArrayAdapter<SongInfo> {    private int resourceId;    public SongAdapter(Context context, int resourceId, List<SongInfo> objects) {        super(context, resourceId, objects);        this.resourceId = resourceId;    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        View view;        ViewHolder holder;        SongInfo songInfo = getItem(position);        if (null == convertView) {            view = LayoutInflater.from(getContext()).inflate(resourceId, null);            holder = new ViewHolder();            holder.tvSongName = (TextView)view.findViewById(R.id.tvSongName);            holder.tvSinger = (TextView)view.findViewById(R.id.tvSinger);            view.setTag(holder);        }else {            view=convertView;            holder = (ViewHolder)view.getTag();        }//      TextView tvSongName = (TextView)view.findViewById(R.id.tvSongName);//      TextView tvSinger = (TextView)view.findViewById(R.id.tvSinger);        holder.tvSongName.setText(songInfo.getSongName());        holder.tvSinger.setText(songInfo.getSinger());        return view;    }    //缓存子布局中的控件实例    class ViewHolder{        TextView tvSongName;        TextView tvSinger;    }}

SongInfo.java

public class SongInfo {    private String songName;    private String singer;    public SongInfo(String songName, String singer) {        this.songName = songName;        this.singer = singer;    }    public String getSongName() {        return songName;    }    public String getSinger() {        return singer;    }}

MainActivity.java

public class MainActivity extends Activity {    private String[] songStrings = { "冰雨 刘德华", "东邪西毒 张学友", "三天三夜 张惠妹",            "齐天大圣 张卫健", "光辉岁月 Beyond", "两只蝴蝶 庞龙", "冰雨 刘德华", "东邪西毒 张学友",            "三天三夜 张惠妹", "齐天大圣 张卫健", "光辉岁月 Beyond", "两只蝴蝶 庞龙", "冰雨 刘德华",            "东邪西毒 张学友", "三天三夜 张惠妹", "齐天大圣 张卫健", "光辉岁月 Beyond", "两只蝴蝶 庞龙" };    private List<SongInfo> songList = new ArrayList<SongInfo>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);//      ArrayAdapter<String> adapter = new ArrayAdapter<String>(//              MainActivity.this, R.layout.song_listview_item,//              songStrings);        initSongList();        SongAdapter songAdapter = new SongAdapter(MainActivity.this, R.layout.song_listview_item, songList);        ListView lvListView=(ListView)findViewById(R.id.lv);        lvListView.setAdapter(songAdapter);        lvListView.setOnItemClickListener(new OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view,                    int position, long id) {                // TODO Auto-generated method stub                SongInfo song=songList.get(position);                Toast.makeText(MainActivity.this, song.getSongName(), Toast.LENGTH_LONG).show();            }        });    }    public void initSongList() {        SongInfo song  = new SongInfo("冰雨", "刘德华");        songList.add(song);        SongInfo song1  = new SongInfo("东邪西毒", "张学友");        songList.add(song1);        SongInfo song2  = new SongInfo("三天三夜", "张惠妹");        songList.add(song2);        SongInfo song3  = new SongInfo("齐天大圣", "张卫健");        songList.add(song3);        SongInfo song4  = new SongInfo("光辉岁月", "Beyond");        songList.add(song4);        SongInfo song5  = new SongInfo("两只蝴蝶", "庞龙");        songList.add(song5);        SongInfo song6  = new SongInfo("冰雨", "刘德华");        songList.add(song6);        SongInfo song7  = new SongInfo("东邪西毒", "张学友");        songList.add(song7);        SongInfo song8  = new SongInfo("三天三夜", "张惠妹");        songList.add(song8);        SongInfo song9  = new SongInfo("齐天大圣", "张卫健");        songList.add(song9);        SongInfo song10  = new SongInfo("光辉岁月", "Beyond");        songList.add(song10);        SongInfo song11  = new SongInfo("两只蝴蝶", "庞龙");        songList.add(song11);        SongInfo song12  = new SongInfo("冰雨", "刘德华");        songList.add(song12);        SongInfo song13  = new SongInfo("东邪西毒", "张学友");        songList.add(song13);        SongInfo song14  = new SongInfo("三天三夜", "张惠妹");        songList.add(song14);        SongInfo song15  = new SongInfo("齐天大圣", "张卫健");        songList.add(song15);        SongInfo song16 = new SongInfo("光辉岁月", "Beyond");        songList.add(song16);        SongInfo song17 = new SongInfo("两只蝴蝶", "庞龙");        songList.add(song17);    }}

接下来两个XML文件
主文件activity_main.xml

<LinearLayout 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:orientation="vertical"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.starnet.mediaplayer2017.MainActivity" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal"        android:background="#FFF0F5" >        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:src="@drawable/ic_launcher" />        <EditText            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:hint="小纯纯" />    </LinearLayout>    <ListView        android:id="@+id/lv"        android:layout_width="match_parent"        android:layout_height="match_parent" >    </ListView></LinearLayout>

listview的子项XML，song_listview_item.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="1"        android:orientation="vertical" >        <TextView            android:id="@+id/tvSongName"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:textSize="30dp" />    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="1"        android:orientation="vertical" >        <TextView            android:id="@+id/tvSinger"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:textSize="30dp" />    </LinearLayout></LinearLayout>