此类作为数据库查询结果bean
public class MusicBean {
private String title;
private String singer;
private String path;
private long time;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getSinger() {
return singer;
}
public void setSinger(String singer) {
this.singer = singer;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public long getTime() {
return time;
}
public void setTime(long time) {
this.time = time;
}
}
此类用来查询数据库和时间转换
public class MusicUtil {
@RequiresApi(api = Build.VERSION_CODES.O)
static public ArrayList<MusicBean> getAllMusic(Context context) {
ArrayList<MusicBean> all = new ArrayList<>();
ContentResolver contentResolver = context.getContentResolver();//获取ContentResolver对象
//调用contentResolver对象的query方法查询系统表的音频文件数据
Cursor cursor = contentResolver.query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null);
//通过cursor取出查询数据存放在musicBean中
while (cursor.moveToNext()) {
MusicBean bean = new MusicBean();
bean.setTitle(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE)));
bean.setSinger(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST)));
bean.setPath(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA)));
bean.setTime(cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION)));
all.add(bean);
}
return all;
}
/*毫秒转化成分钟加秒*/
public static String formatTime(long time) {
String min = (time / (1000 * 60)) + "";//得到分钟
String second = (time % (1000 * 60) / 1000) + "";//得到秒
return min + "分" + second + "秒";
}
}
此类是activity类，实现转化资源文件，动态申请权限，自定义ListView适配器，将bean中封装的数据更新到item中的数据项中显示出来
ublic class MainActivity extends AppCompatActivity {
ListView listView;
MediaPlayer mp; //播放音频对象
ArrayList<MusicBean> data;
@RequiresApi(api = Build.VERSION_CODES.O)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = findViewById(R.id.lv);
mp = new MediaPlayer();
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
data = MusicUtil.getAllMusic(this);
MyAdapter myAdapter = new MyAdapter();
listView.setAdapter(myAdapter);
} else {
requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 101);
}
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (mp.isPlaying()) {
mp.stop();
} else {
mp.reset();
try {
mp.setDataSource(data.get(position).getPath());
mp.prepare();
mp.start();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
}
/*权限申请结果回调方法*/
@RequiresApi(api = Build.VERSION_CODES.O)
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == 101 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
data = MusicUtil.getAllMusic(this);
MyAdapter myAdapter = new MyAdapter();
listView.setAdapter(myAdapter);
} else {
Toast.makeText(getApplicationContext(), "请授予权限否则无法使用", Toast.LENGTH_SHORT).show();
}
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
/*自定义适配器*/
class MyAdapter extends BaseAdapter {
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.item, null);
MusicBean bean = data.get(position);
TextView tv_title = view.findViewById(R.id.tv_title);
TextView tv_singer = view.findViewById(R.id.tv_singer);
TextView tv_time = view.findViewById(R.id.tv_time);
TextView tv_path = view.findViewById(R.id.tv_path);
tv_title.setText(bean.getTitle());
TextPaint tp = tv_title.getPaint();//中文字体加粗
tp.setFakeBoldText(true);
tv_singer.setText(bean.getSinger());
tv_time.setText(MusicUtil.formatTime(bean.getTime()));
tv_path.setText(bean.getPath());
if(position%2==0){ //改变背景颜色
view.setBackgroundResource(R.drawable.item);
}
return view;
}
}
}
有一点要提一下，使用资源文件设置listView的背景颜色，在此分享给大家，在darwable资源目录下新建xml文件
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" android:drawable="@color/colorAccent"></item>
<item android:state_pressed="false" android:drawable="@color/coloritem"></item>
</selector>
其中true表示未长按时，false表示长按选中时
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
<?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="match_parent">
<TextView
android:id="@+id/tv_title"
android:layout_width="0dp"
android:layout_height="40dp"
android:layout_weight="1"/>
<TextView
android:id="@+id/tv_singer"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"/>
<TextView
android:id="@+id/tv_path"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"/>
<TextView
android:id="@+id/tv_time"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"/>
</LinearLayout>