android音乐播放器_歌曲列表

  歌曲列表是来显示SD卡或手机内存中的歌曲，因为android会自动扫描媒体对象，直接使用MediaStore就可以显示歌曲名称、艺术家、缩略图等。再次使用ListView来显示这些信息，xml布局很简单就是一个ListView：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <ListView        android:id="@+id/music_list"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@drawable/listbg"        android:cacheColorHint="#00000000" >    </ListView></LinearLayout>

  既然使用ListView来显示歌曲信息，例如歌曲标题、歌手、缩略图以及时长等等。那么如何获取这些信息以及如何显示到ListView中呢？要分为两个步骤：

  (1)使用MediaStore获取歌曲信息

  (2)自定义Adapter将MediaStore获取歌曲信息显示出来

  

/** *  */package com.android.musicplayer.activity;import java.io.File;import com.android.musicplayer.adapter.MusicListAdapter;import com.android.musicplayer.util.ScanSdReceiver;import android.app.Activity;import android.app.AlertDialog;import android.content.BroadcastReceiver;import android.content.Context;import android.content.DialogInterface;import android.content.Intent;import android.content.IntentFilter;import android.database.Cursor;import android.media.AudioManager;import android.os.Bundle;import android.provider.MediaStore;import android.view.ContextMenu;import android.view.KeyEvent;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.ContextMenu.ContextMenuInfo;import android.view.View.OnCreateContextMenuListener;import android.widget.AdapterView;import android.widget.ListView;import android.widget.AdapterView.OnItemClickListener;/** * @author Administrator *  */public class SongsActivity extends Activity {private int[] _ids;// 保存音乐ID临时数组private String[] _artists;// 保存艺术家private String[] _titles;// 标题临时数组private ListView listView;// 列表对象private Cursor cursor;private MusicListAdapter musicListAdapter;private AlertDialog ad = null;private AlertDialog.Builder builder = null;private static final String MUSIC_LIST = "com.android.musicplayer.activity.list";/** * 定义查找音乐信息数组，1.标题 2.音乐时间 3.艺术家 4.音乐id 5.显示名字 6.数据 */String[] media_music_info = new String[] { MediaStore.Audio.Media.TITLE,MediaStore.Audio.Media.DURATION, MediaStore.Audio.Media.ARTIST,MediaStore.Audio.Media._ID, MediaStore.Audio.Media.DISPLAY_NAME,MediaStore.Audio.Media.DATA, MediaStore.Audio.Media.ALBUM_ID };@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_songs);listView = (ListView) findViewById(R.id.music_list);listView.setOnItemClickListener(new MusicListOnClickListener());// 创建一个ListView监听器对象showMusicList();}private void showMusicList() {cursor = getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, media_music_info,null, null, MediaStore.Audio.Media.DEFAULT_SORT_ORDER);cursor.moveToFirst();// 将游标移动到初始位置_ids = new int[cursor.getCount()];// 返回int的一个列_artists = new String[cursor.getCount()];// 返回String的一个列_titles = new String[cursor.getCount()];// 返回String的一个列for (int i = 0; i < cursor.getCount(); i++) {_ids[i] = cursor.getInt(3);_titles[i] = cursor.getString(0);_artists[i] = cursor.getString(2);cursor.moveToNext();// 将游标移到下一行}musicListAdapter = new MusicListAdapter(this, cursor);listView.setAdapter(musicListAdapter);// 用setAdapter装载数据listView.setOnCreateContextMenuListener(new ContextMenuListener());}public boolean onKeyDown(int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK) {if (scanSdReceiver != null)unregisterReceiver(scanSdReceiver);Intent intent = new Intent();intent.setClass(this, MainActivity.class);startActivity(intent);finish();}return true;}}

  同样的使用自定义Adapter来显示歌曲：MusicListAdapter，这里有一点要说明的是，获取歌曲内置的图片比较麻烦一些。

/** *  */package com.android.musicplayer.adapter;import java.io.FileDescriptor;import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStream;import com.android.musicplayer.activity.R;import android.content.ContentResolver;import android.content.ContentUris;import android.content.Context;import android.database.Cursor;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.ParcelFileDescriptor;import android.provider.MediaStore;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.TextView;/** * @author Administrator *  */public class MusicListAdapter extends BaseAdapter {private Context myContext;private Cursor myCursor;private int pos = -1;public MusicListAdapter(Context context, Cursor cursor) {myContext = context;myCursor = cursor;}@Overridepublic int getCount() {return myCursor.getCount();}@Overridepublic Object getItem(int position) {return position;}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder holder = null;View vi = convertView;if (convertView == null) {holder = new ViewHolder();vi = LayoutInflater.from(myContext).inflate(R.layout.musiclist,null);holder.tv_music = (TextView) vi.findViewById(R.id.music1);holder.tv_singer = (TextView) vi.findViewById(R.id.singer);holder.tv_time = (TextView) vi.findViewById(R.id.time);holder.img = (ImageView) vi.findViewById(R.id.listitem);vi.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}myCursor.moveToPosition(position);if (myCursor.getString(0).length() > 15) {try {String musicTitle = myCursor.getString(0).trim().substring(0, 12)+ "...";holder.tv_music.setText(musicTitle);} catch (Exception e) {e.printStackTrace();}} else {holder.tv_music.setText(myCursor.getString(0).trim());}if (myCursor.getString(2).equals("<unknown>")) {holder.tv_singer.setText("未知艺术家?");} else {holder.tv_singer.setText(myCursor.getString(2));}if (position == pos) {holder.img.setImageResource(R.drawable.isplaying);} else {// img.setImageResource(R.drawable.item);Bitmap bm = getArtwork(myContext, myCursor.getInt(3),myCursor.getInt(myCursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID)),true);holder.img.setImageBitmap(bm);}return vi;}public void setItemIcon(int position) {pos = position;}public String toTime(int time) {time /= 1000;int minute = time / 60;int hour = minute / 60;int second = time % 60;minute %= 60;return String.format("%02d:%02d", minute, second);}public static Bitmap getArtwork(Context context, long song_id,long album_id, boolean allowdefault) {Log.v("ADW", "getArtwork");if (album_id < 0) {// This is something that is not in the database, so get the album// art directly// from the file.if (song_id >= 0) {Bitmap bm = getArtworkFromFile(context, song_id, -1);if (bm != null) {return bm;}}if (allowdefault) {return getDefaultArtwork(context);}return null;}ContentResolver res = context.getContentResolver();Uri uri = ContentUris.withAppendedId(sArtworkUri, album_id);if (uri != null) {InputStream in = null;try {in = res.openInputStream(uri);BitmapFactory.Options options = new BitmapFactory.Options();options.inSampleSize = 1;options.inJustDecodeBounds = true;BitmapFactory.decodeStream(in, null, options);options.inSampleSize = computeSampleSize(options, 30);options.inJustDecodeBounds = false;options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;in = res.openInputStream(uri);return BitmapFactory.decodeStream(in, null, options);} catch (FileNotFoundException ex) {// The album art thumbnail does not actually exist. Maybe the// user deleted it, or// maybe it never existed to begin with.Bitmap bm = getArtworkFromFile(context, song_id, album_id);if (bm != null) {if (bm.getConfig() == null) {bm = bm.copy(Bitmap.Config.RGB_565, false);if (bm == null && allowdefault) {return getDefaultArtwork(context);}}} else if (allowdefault) {bm = getDefaultArtwork(context);}return bm;} finally {try {if (in != null) {in.close();}} catch (IOException ex) {}}}return null;}private static Bitmap getArtworkFromFile(Context context, long songid,long albumid) {Bitmap bm = null;byte[] art = null;String path = null;if (albumid < 0 && songid < 0) {throw new IllegalArgumentException("Must specify an album or a song id");}try {BitmapFactory.Options options = new BitmapFactory.Options();FileDescriptor fd = null;if (albumid < 0) {Uri uri = Uri.parse("content://media/external/audio/media/"+ songid + "/albumart");ParcelFileDescriptor pfd = context.getContentResolver().openFileDescriptor(uri, "r");if (pfd != null) {fd = pfd.getFileDescriptor();// bm = BitmapFactory.decodeFileDescriptor(fd,null,options);}} else {Uri uri = ContentUris.withAppendedId(sArtworkUri, albumid);ParcelFileDescriptor pfd = context.getContentResolver().openFileDescriptor(uri, "r");if (pfd != null) {fd = pfd.getFileDescriptor();// bm = BitmapFactory.decodeFileDescriptor(fd,null,options);}}Log.v("ADW", "getArtworkFromFile");options.inSampleSize = 1;options.inJustDecodeBounds = true;BitmapFactory.decodeFileDescriptor(fd, null, options);options.inSampleSize = 500;// computeSampleSize(options, 800);options.inJustDecodeBounds = false;options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;bm = BitmapFactory.decodeFileDescriptor(fd, null, options);} catch (FileNotFoundException ex) {}if (bm != null) {mCachedBit = bm;}return bm;}static int computeSampleSize(BitmapFactory.Options options, int target) {int w = options.outWidth;int h = options.outHeight;int candidateW = w / target;int candidateH = h / target;int candidate = Math.max(candidateW, candidateH);if (candidate == 0)return 1;if (candidate > 1) {if ((w > target) && (w / candidate) < target)candidate -= 1;}if (candidate > 1) {if ((h > target) && (h / candidate) < target)candidate -= 1;}Log.v("ADW", "candidate:" + candidate);return candidate;}private static Bitmap getDefaultArtwork(Context context) {BitmapFactory.Options opts = new BitmapFactory.Options();opts.inPreferredConfig = Bitmap.Config.RGB_565;return BitmapFactory.decodeStream(context.getResources().openRawResource(R.drawable.item), null, opts);}private static final Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");private static final BitmapFactory.Options sBitmapOptions = new BitmapFactory.Options();private static Bitmap mCachedBit = null;class ViewHolder {public TextView tv_music, tv_singer, tv_time;public ImageView img;}}