最近在做Android 的MP3播放的項目，要實現歌詞的自動滾動，以及同步顯示。
lyric的歌詞解析主要用yoyoplayer里面的，顯示部分參考了這里 ，這里只是模擬MP3歌詞的滾動。
先上一下效果圖：
滾動實現的代碼其實也簡單。顯示畫出當前時間點的歌詞，然后再分別畫出改歌詞后面和前面的歌詞，前面的部分往上推移，后面的部分往下推移，這樣就保持了當前時間歌詞在中間。
代碼如下 LyricView，相關信息在注釋了標明了。
package ru.org.piaozhiye.lyric; import java.io.File; import java.util.List; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.graphics.Typeface; import android.util.AttributeSet; import android.widget.TextView; /** * @author root * */ public class LyricView extends TextView { private Paint mPaint; private float mX; private static Lyric mLyric; private Paint mPathPaint; public String test = "test"; public int index = 0; private List<Sentence> list; public float mTouchHistoryY; private int mY; private long currentDunringTime; // 當前行歌詞持續的時間，用該時間來sleep private float middleY;// y軸中間 private static final int DY = 50; // 每一行的間隔 public LyricView(Context context) { super(context); init(); } public LyricView(Context context, AttributeSet attr) { super(context, attr); init(); } public LyricView(Context context, AttributeSet attr, int i) { super(context, attr, i); init(); } private void init() { setFocusable(true); PlayListItem pli = new PlayListItem("Because Of You", "/sdcard/MP3/Because Of You.mp3", 0L, true); mLyric = new Lyric(new File("/sdcard/MP3/Because Of You.lrc"), pli); list = mLyric.list; // 非高亮部分 mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setTextSize(22); mPaint.setColor(Color.WHITE); mPaint.setTypeface(Typeface.SERIF); // 高亮部分 當前歌詞 mPathPaint = new Paint(); mPathPaint.setAntiAlias(true); mPathPaint.setColor(Color.RED); mPathPaint.setTextSize(22); mPathPaint.setTypeface(Typeface.SANS_SERIF); } protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawColor(0xEFeffff); Paint p = mPaint; Paint p2 = mPathPaint; p.setTextAlign(Paint.Align.CENTER); if (index == -1) return; p2.setTextAlign(Paint.Align.CENTER); // 先畫當前行，之后再畫他的前面和后面，這樣就保持當前行在中間的位置 canvas.drawText(list.get(index).getContent(), mX, middleY, p2); float tempY = middleY; // 畫出本句之前的句子 for (int i = index - 1; i >= 0; i--) { // Sentence sen = list.get(i); // 向上推移 tempY = tempY - DY; if (tempY < 0) { break; } canvas.drawText(list.get(i).getContent(), mX, tempY, p); // canvas.translate(0, DY); } tempY = middleY; // 畫出本句之后的句子 for (int i = index + 1; i < list.size(); i++) { // 往下推移 tempY = tempY + DY; if (tempY > mY) { break; } canvas.drawText(list.get(i).getContent(), mX, tempY, p); // canvas.translate(0, DY); } } protected void onSizeChanged(int w, int h, int ow, int oh) { super.onSizeChanged(w, h, ow, oh); mX = w * 0.5f; // remember the center of the screen mY = h; middleY = h * 0.5f; } // /** * @param time * 當前歌詞的時間軸 * * @return currentDunringTime 歌詞只需的時間 */ public long updateIndex(long time) { // 歌詞序號 index = mLyric.getNowSentenceIndex(time); if (index == -1) return -1; Sentence sen = list.get(index); // 返回歌詞持續的時間，在這段時間內sleep return currentDunringTime = sen.getDuring(); } } 剩下的就是使用他了。就是取出歌詞的index，和該行歌詞持續的時間進行sleep。
package ru.org.piaozhiye; import java.io.IOException; import ru.org.piaozhiye.lyric.LyricView; import android.app.Activity; import android.media.MediaPlayer; import android.os.Bundle; import android.os.Handler; public class LyricDemo extends Activity { private MediaPlayer mp; private LyricView lyricView; private String path = "/sdcard/MP3/Because Of You.mp3"; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); lyricView = (LyricView) findViewById(R.id.audio_lrc); mp = new MediaPlayer(); mp.reset(); try { mp.setDataSource(path); mp.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(); } mp.start(); new Thread(new UIUpdateThread()).start(); } class UIUpdateThread implements Runnable { long time = 100; // 開始 的時間，不能為零，否則前面幾句歌詞沒有顯示出來 public void run() { while (mp.isPlaying()) { long sleeptime = lyricView.updateIndex(time); time += sleeptime; mHandler.post(mUpdateResults); if (sleeptime == -1) return; try { Thread.sleep(sleeptime); } 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 } }; } 整個project的源碼。包括yoyoplayer的解析lyric部分代碼。
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