Android實現歌曲播放時歌詞同步顯示

我們需要讀取以上歌詞文件的每一行轉換成成一個個歌詞實體：

public class LyricObject {   

 
    public int begintime; // 開始時間    
    public int endtime; // 結束時間    
    public int timeline; // 單句歌詞用時    
    public String lrc; // 單句歌詞    
}

可根據當前播放器的播放進度與每句歌詞的開始時間，得到當前屏幕中央高亮顯示的那句歌詞。在 UI線程中另起線程，通過回調函數 onDraw() 每隔100ms重新繪制屏幕，實現歌詞平滑滾動的動畫效果。 MainActivity代碼如下：

import java.io.IOException;    
import android.app.Activity;    
import android.media.MediaPlayer;    
import android.net.Uri;    
import android.os.Bundle;    
import android.os.Environment;    
import android.os.Handler;    
import android.view.View;    
import android.view.View.OnClickListener;    
import android.widget.Button;    
import android.widget.SeekBar;    
import android.widget.SeekBar.OnSeekBarChangeListener;    
        
public class MainActivity extends Activity {    
    /** Called when the activity is first created. */
    private LyricView lyricView;    
    private MediaPlayer mediaPlayer;    
    private Button button;    
    private SeekBar seekBar;    
    private String mp3Path;    
    private int INTERVAL=45;//歌詞每行的間隔    
        
    @Override
    public void onCreate(Bundle savedInstanceState) {    
        super.onCreate(savedInstanceState);    
        // this.requestWindowFeature(Window.FEATURE_NO_TITLE);    
        // getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);    
        setContentView(R.layout.main);    
        
        mp3Path = Environment.getExternalStorageDirectory().getAbsolutePath() + 

"/LyricSync/1.mp3";    
        
        lyricView = (LyricView) findViewById(R.id.mylrc);    
        mediaPlayer = new MediaPlayer();    
        // this.requestWindowFeature(Window.FEATURE_NO_TITLE);    
        
        ResetMusic(mp3Path);    
        SerchLrc();    
        lyricView.SetTextSize();    
        
        button = (Button) findViewById(R.id.button);    
        button.setText("播放");    
        
        seekBar = (SeekBar) findViewById(R.id.seekbarmusic);    
        seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {    
        
            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {    
                // TODO Auto-generated method stub    
        
            }    
        
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {    
                // TODO Auto-generated method stub    
        
            }    
        
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress,    
                    boolean fromUser) {    
                // TODO Auto-generated method stub    
                if (fromUser) {    
                    mediaPlayer.seekTo(progress);    
                    lyricView.setOffsetY(220 - lyricView.SelectIndex(progress)     
                            * (lyricView.getSIZEWORD() + INTERVAL-1));    
        
                }    
            }    
        });    
        
        button.setOnClickListener(new OnClickListener() {    
        
            @Override
            public void onClick(View v) {    
                // TODO Auto-generated method stub    
                if (mediaPlayer.isPlaying()) {    
                    button.setText("播放");    
                    mediaPlayer.pause();    
                } else {    
                    button.setText("暫停");    
                    mediaPlayer.start();    
                    lyricView.setOffsetY(220 - lyricView.SelectIndex(mediaPlayer.getCurrentPosition())    
                            * (lyricView.getSIZEWORD() + INTERVAL-1));    
        
                }    
            }    
        });    
        
        mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {    
            @Override
            public void onCompletion(MediaPlayer mp) {    
                ResetMusic(mp3Path);    
                lyricView.SetTextSize();    
                lyricView.setOffsetY(200);    
                mediaPlayer.start();    
            }    
        });    
        seekBar.setMax(mediaPlayer.getDuration());    
        new Thread(new runable()).start();    
    }    
        
    public void SerchLrc() {    
        String lrc = mp3Path;    
        lrc = lrc.substring(0, lrc.length() - 4).trim() + ".lrc".trim();    
        LyricView.read(lrc);    
        lyricView.SetTextSize();    
        lyricView.setOffsetY(350);    
    }    
        
    public void ResetMusic(String path) {    
        
        mediaPlayer.reset();    
        try {    
        
            mediaPlayer.setDataSource(mp3Path);    
            mediaPlayer.prepare();    
        } catch (IllegalArgumentException e) {    
            // TODO Auto-generated catch block    
            e.printStackTrace();    
        } catch (IllegalStateException e) {    
            // TODO Auto-generated catch block    
            e.printStackTrace();    
        } catch (IOException e) {    
            // TODO Auto-generated catch block    
            e.printStackTrace();    
        }    
    }    
        
    class runable implements Runnable {    
        
        @Override
        public void run() {    
            // TODO Auto-generated method stub    
            while (true) {    
        
                try {    
                    Thread.sleep(100);    
                    if (mediaPlayer.isPlaying()) {    
                        lyricView.setOffsetY(lyricView.getOffsetY() - lyricView.SpeedLrc());    
                        lyricView.SelectIndex(mediaPlayer.getCurrentPosition());    
                        seekBar.setProgress(mediaPlayer.getCurrentPosition());    
                        mHandler.post(mUpdateResults);    
                    }    
                } catch (InterruptedException e) {    
                    // TODO Auto-generated catch block    
                    e.printStackTrace();    
                }    
            }    
        }    
    }    
        
    Handler mHandler = new Handler();    
    Runnable mUpdateResults = new Runnable() {    
        public void run() {    
            lyricView.invalidate(); // 更新視圖    
        }    
    };    
}