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Android上MP3播放器的实现源代码01

分类: IT文章 • 2024-07-17 21:44:49
Android下MP3播放器的实现源代码01
第一个类AlbumActivity

package com.alex.media;

import com.alex.media.ArtistActivity.ListItemClickListener;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.AdapterView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.LinearLayout.LayoutParams;

public class AlbumActivity extends Activity {
	private int[] _ids;
	private String[]_titles;
	private ListView listview;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		Intent intent = this.getIntent();
		String albumName;
		albumName = intent.getExtras().getString("albums");
		listview = new ListView(this);
		Cursor c = this.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
				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.ALBUM + "='" + albumName+"'", 
				null,
				null);
	   c.moveToFirst();
	   _ids = new int[c.getCount()];
	   _titles = new String[c.getCount()];
	   for(int i=0;i<c.getCount();i++){
	       _ids[i] = c.getInt(3);
	       _titles[i] = c.getString(0);
	       c.moveToNext();
	  }
	   listview.setAdapter(new MusicListAdapter(this, c));
	   listview.setOnItemClickListener(new ListItemClickListener());
	   LinearLayout list = new LinearLayout(this);
	   list.setBackgroundResource(R.drawable.listbg);
	   LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
	   LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
	   list.addView(listview,params);
	   setContentView(list);
	   
	    
	}
	 class ListItemClickListener implements OnItemClickListener{

	    	@Override
	    	public void onItemClick(AdapterView<?> arg0, View view, int position, long id) {
	    		// TODO Auto-generated method stub
	    		Intent intent = new Intent(AlbumActivity.this,MusicActivity.class);
	    		intent.putExtra("_ids", _ids);
	    		intent.putExtra("_titles", _titles);
	    		intent.putExtra("position", position);
	    		startActivity(intent);
	    		finish();
	    	}
	    	
	    }
}



第二个类AlbumListAdapter
package com.alex.media;

import java.util.HashMap;

import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.provider.MediaStore;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class AlbumListAdapter extends BaseAdapter{

	private Context myCon;
	private String[] albums;
	private HashMap<String, String> myMap;

	public AlbumListAdapter(Context con,String[] str1, HashMap<String, String> map){
		myCon = con;
		albums = str1;
		myMap = map;
	}
	
	@Override
	public int getCount() {
		return albums.length;
	}

	@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) {
		convertView = LayoutInflater.from(myCon).inflate(R.layout.albumslist,
				null);
		/**
		 * 设置专辑名
		 */
		TextView album = (TextView)convertView.findViewById(R.id.album);
		if (albums[position].length()>24){
			try {
				String albumName = bSubstring(albums[position],24);
				album.setText(albumName);
			} catch (Exception e) {
				e.printStackTrace();
			}
			
		} else {
			album.setText(albums[position]);
		}
		/**
		 * 设置艺术家姓名
		 */
		TextView artist = (TextView)convertView.findViewById(R.id.mysinger);
		if (myMap.get(albums[position]).equals("<unknown>")){
			artist.setText("未知艺术家");
		} else{
			artist.setText(myMap.get(albums[position]));
		}
		
		ImageView Albumsitem = (ImageView)convertView.findViewById(R.id.Albumsitem);
		Albumsitem.setImageResource(R.drawable.album);
		return convertView;
	}
	
	/**
	 * 字符串裁剪
	 * @param s
	 * @param length
	 * @return
	 * @throws Exception
	 */
	public static String bSubstring(String s, int length) throws Exception  
	{  
	 
	    byte[] bytes = s.getBytes("Unicode");  
	    int n = 0; // 表示当前的字节数  
	    int i = 2; // 要截取的字节数，从第3个字节开始  
	    for (; i < bytes.length && n < length; i++)  
	    {  
	        // 奇数位置，如3、5、7等，为UCS2编码中两个字节的第二个字节  
	        if (i % 2 == 1)  
	        {  
	            n++; // 在UCS2第二个字节时n加1  
	        }  
	        else 
	        {  
	            // 当UCS2编码的第一个字节不等于0时，该UCS2字符为汉字，一个汉字算两个字节  
	            if (bytes[i] != 0)  
	            {  
	                n++;  
	            }  
	        }  
	    }  
	    // 如果i为奇数时，处理成偶数  
	    if (i % 2 == 1)  
	 
	    {  
	        // 该UCS2字符是汉字时，去掉这个截一半的汉字  
	        if (bytes[i - 1] != 0)  
	            i = i - 1;  
	        // 该UCS2字符是字母或数字，则保留该字符  
	        else 
	            i = i + 1;  
	    }  
	 
	    return new String(bytes, 0, i, "Unicode");  
	}  

}


第三个类ArtistActivity
package com.alex.media;

import com.alex.media.RecentlyActivity.ListItemClickListener;

import android.app.Activity;
import android.content.Context;
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.View;
import android.widget.AdapterView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.LinearLayout.LayoutParams;

public class ArtistActivity extends Activity {
	private int[] _ids;
	private String[]_titles;
	private ListView listview;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		Intent intent = this.getIntent();
		String artistName;
		if (intent.getExtras().getString("artist").equals("未知艺术家")){
			artistName = "<unknown>";
		} else{
			artistName = intent.getExtras().getString("artist");
		}
		listview = new ListView(this);
		Cursor c = this.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
				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.ARTIST + "='" + artistName+"'", 
				null,
				null);
	   c.moveToFirst();
	   _ids = new int[c.getCount()];
	   _titles = new String[c.getCount()];
	   for(int i=0;i<c.getCount();i++){
	       _ids[i] = c.getInt(3);
	       _titles[i] = c.getString(0);
	       c.moveToNext();
	  }
	   listview.setAdapter(new MusicListAdapter(this, c));
	   listview.setOnItemClickListener(new ListItemClickListener());
	   LinearLayout list = new LinearLayout(this);
	   list.setBackgroundResource(R.drawable.listbg);
	   LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
	   LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
	   list.addView(listview,params);
	   setContentView(list);
	   
	    
	}
	 class ListItemClickListener implements OnItemClickListener{

	    	@Override
	    	public void onItemClick(AdapterView<?> arg0, View view, int position, long id) {
	    		// TODO Auto-generated method stub
	    		Intent intent = new Intent(ArtistActivity.this,MusicActivity.class);
	    		intent.putExtra("_ids", _ids);
	    		intent.putExtra("_titles", _titles);
	    		intent.putExtra("position", position);
	    		startActivity(intent);
	    		finish();
	    	}
	    	
	    }

}


第四个类 ArtistListAdapter
package com.alex.media;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ArtistListAdapter extends BaseAdapter{

	private Context myCon;
	private String[] artists;
	
	public ArtistListAdapter(Context con,String[] str1){
		myCon = con;
		artists = str1;
	}
	@Override
	public int getCount() {
		return artists.length;
	}

	@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) {
		convertView = LayoutInflater.from(myCon).inflate(R.layout.artistslist,
				null);
		
		//设置艺术家姓名
		TextView artist = (TextView)convertView.findViewById(R.id.artist);
		artist.setText(artists[position]);
		
		//设置列表项图标
		ImageView Artistsitem = (ImageView)convertView.findViewById(R.id.Artistsitem);
		Artistsitem.setImageResource(R.drawable.artist);
		return convertView;
	}

}



第五个类ClicksActivity

package com.alex.media;

import com.alex.media.ListActivity.ListItemClickListener;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.media.AudioManager;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.KeyEvent;
import android.view.View;
import android.widget.AdapterView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.LinearLayout.LayoutParams;

public class ClicksActivity extends Activity {
	private DBHelper dbHelper = null;
	private ListView listview;
	private int[] _ids;
	private String[]_titles;
	Cursor cursor = null;
	int[] music_id;
	//关于音量的变量
	private AudioManager mAudioManager = null;
	private int maxVolume;//最大音量
	private int currentVolume;//当前音量
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		dbHelper = new DBHelper(this, "music.db", null, 2);
		cursor = dbHelper.queryByClicks();
		cursor.moveToFirst();
		int num;
		if (cursor!=null){
			num = cursor.getCount();
		} else{
			return;
		}
		String idString ="";
		if (num>=10){
			for(int i=0;i<10;i++){
				music_id = new int[10];
				music_id[i]=cursor.getInt(cursor.getColumnIndex("music_id"));
				if (i<9){
					idString = idString+music_id[i]+",";
				} else{
					idString = idString+music_id[i];
				}
				cursor.moveToNext();
			} 
		}else if(num>0){
			for(int i=0;i<num;i++){
				music_id = new int[num];
				music_id[i]=cursor.getInt(cursor.getColumnIndex("music_id"));
				if (i<num-1){
					idString = idString+music_id[i]+",";
				} else{
					idString = idString+music_id[i];
				}
				cursor.moveToNext();
			}
		}
		System.out.println(idString);
		if (cursor!=null){
			cursor.close();
			cursor=null;
		}
		listview = new ListView(this);
		Cursor c = this.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
        			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._ID + " in ("+ idString + ")", null, null);
		
		  c.moveToFirst();
	        _ids = new int[c.getCount()];
	        _titles = new String[c.getCount()];
	        for(int i=0;i<c.getCount();i++){
	        	_ids[i] = c.getInt(3);
	        	_titles[i] = c.getString(0);
	        	c.moveToNext();
	        }
	        listview.setAdapter(new MusicListAdapter(this, c));
	        listview.setOnItemClickListener(new ListItemClickListener());
	        
	        mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE); 
			maxVolume = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);//获得最大音量  
			currentVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);//获得当前音量 
			LinearLayout list = new LinearLayout(this);
			list.setBackgroundResource(R.drawable.listbg);
	        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
	        LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
	        list.addView(listview,params);
	        setContentView(list);
	    }
	   
	    class ListItemClickListener implements OnItemClickListener{

	    	@Override
	    	public void onItemClick(AdapterView<?> arg0, View view, int position, long id) {
	    		// TODO Auto-generated method stub
	    		Intent intent = new Intent(ClicksActivity.this,MusicActivity.class);
	    		intent.putExtra("_ids", _ids);
	    		intent.putExtra("_titles", _titles);
	    		intent.putExtra("position", position);
	    		
	    		startActivity(intent);
	    		finish();
	    	}
	    	
	    }
	    public boolean onKeyDown(int keyCode, KeyEvent event) {
			if (keyCode == event.KEYCODE_BACK) {
				Intent intent = new Intent();
				intent.setClass(this, MainActivity.class);
				startActivity(intent);
				finish();
			}
			return true;
	    }
	    public boolean dispatchKeyEvent(KeyEvent event) { 
			int action = event.getAction(); 
			int keyCode = event.getKeyCode(); 
			switch (keyCode) { 
				case KeyEvent.KEYCODE_VOLUME_UP: 
				if (action == KeyEvent.ACTION_UP) {
					if (currentVolume<maxVolume){
						currentVolume = currentVolume + 1;
						mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume, 0);
					} else {
						mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume, 0);
					}
				} 
				return false; 
				case KeyEvent.KEYCODE_VOLUME_DOWN: 
				if (action == KeyEvent.ACTION_UP) { 
					if (currentVolume>0){
						currentVolume = currentVolume - 1;
						mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume , 0);
					} else {
						mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume, 0);
					}
				} 
				return false; 
				default: 
				return super.dispatchKeyEvent(event); 
			} 
		}
}



第六个类DBHelper


package com.alex.media;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;

public class DBHelper extends SQLiteOpenHelper {
	private Cursor c = null;
	private static final String CREATE_TAB = "create table "
		+ "music(_id integer primary key autoincrement,music_id integer,clicks integer," +
				"latest text)";
	private static final String TAB_NAME = "music";
	private SQLiteDatabase db = null;
	public DBHelper(Context context, String name, CursorFactory factory,
			int version) {
		super(context, name, factory, version);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		this.db = db;
		db.execSQL(CREATE_TAB);
	}
	
	public void insert(ContentValues values){
		SQLiteDatabase db = getWritableDatabase();
		db.insert(TAB_NAME, null, values);
	}

	public void update(ContentValues values,int id){
		SQLiteDatabase db = getWritableDatabase();
		db.update(TAB_NAME, values, "music_id="+id, null);
	}
	
	public void delete(int id){
		if (db == null){
			db = getWritableDatabase();
		}
		db.delete(TAB_NAME, "music_id=?", new String[]{String.valueOf(id)});
	}
	
	public Cursor query(int id){
		SQLiteDatabase db = getReadableDatabase();
		c = db.query(TAB_NAME, null, "music_id=?", new String[]{String.valueOf(id)}, null, null, null);
		return c;
	}
	
	public Cursor queryByClicks(){//按点击量查询
		SQLiteDatabase db = getReadableDatabase();
		c = db.query(TAB_NAME, null, null, null, null, null, "clicks desc");
		return c;
	}
	
	public Cursor queryRecently(){//按时间降序查询
		SQLiteDatabase db = getReadableDatabase();
		c = db.query(TAB_NAME, null, null, null, null, null, "latest desc");
		return c;
	}
	
	public void close(){
		if (db != null){
			db.close();
			db=null;
		}
		if (c!=null){
			c.close();
			c=null;
		}
	}
	
	@Override
	public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {

	}

}

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