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：

  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 };

	@Override
	protected 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;
	}

	@Override
	public int getCount() {
		return myCursor.getCount();
	}

	@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) {
		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("")) {
			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;
	}
}