music player：一（歌词显示，LyricView，Canvas）---自动滚动
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????? 网上androi播放器虽然挺多，感觉提供的歌词显示功能比较死板，要么搜索给的条件死死的，要么放置sdcard内部的歌词格式需要统一，应该提供类似文件夹浏览的功能。^_^，不过在这之前先搞定歌词的现实界面：
????? 转载请注明http://ishelf.iteye.com/admin/blogs/740402
??? ? 播放器的歌词界面实现以下几个功能
???? 不多说了直接贴代码，首先开启一个线程每隔一段时间往view中送入一串字符
import android.os.Bundle;import android.os.Handler;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class TextAlign extends GraphicsActivity implements OnClickListener {private SampleView mView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);// Animation in = AnimationUtils.loadAnimation(this, R.anim.push_up_in);// mView.setAnimation(in);setContentView(R.layout.main);mView =(SampleView) findViewById(R.id.text01);Button bt = (Button) findViewById(R.id.Button01);bt.setOnClickListener(this);new Thread(new UIUpdateThread()).start();}class UIUpdateThread implements Runnable {long time = 40000;long sleeptime = 100;public void run() {try {while (time < 200000) {Thread.sleep(sleeptime);mView.updateIndex(time);//.index = mLyric.getNowSentenceIndex(time);//Log.v("UIThread", mView.index + ":" + time);time += sleeptime;mHandler.post(mUpdateResults);}} catch (InterruptedException e) {e.printStackTrace();}}}Handler mHandler = new Handler();Runnable mUpdateResults = new Runnable() {public void run() {mView.invalidate(); // 更新视图}};@Overridepublic void onClick(View v) {mView.mTouchHistoryY -=30;mHandler.post(mUpdateResults);}}???? 这里将时间送到SampleView中，该类对此时间进行加工得到一系列list（该list是动态生成的），从而根据时间的推移递增的得到一系列的字串。这个过程模拟了歌词的显示过程
????? 接下来的SampleView继承了TextView并重载了onDraw方法.注意，这里只给了个sample，里面歌词怎么生成的见YOYOPlayer。这里就不给代码了
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.util.Log;import android.view.MotionEvent;import android.widget.TextView;import android.widget.Toast;import com.android.lyric.Lyric;import com.android.lyric.PlayListItem;import com.android.lyric.Sentence;public class SampleView extends TextView {private Paint mPaint;private float mX;private static Lyric mLyric;private Path mPath;private Paint mPathPaint;public String test = "test";public int index = 0;private List<Sentence> list;private float mTouchStartY;private float mTouchCurrY;public float mTouchHistoryY;private int mY;private long currentTime;private long currentDunringTime;private long sentenctTime;private float middleY;private String middleContent="Empty";private static final int DY = 30;private static void makePath(Path p) {p.moveTo(10, 0);p.cubicTo(100, -50, 200, 50, 300, 0);}public SampleView(Context context) {super(context);init();}public SampleView(Context context,AttributeSet attr) {super(context,attr);init();}public SampleView(Context context,AttributeSet attr,int i) {super(context,attr,i);init();}private void init() {setFocusable(true);PlayListItem pli = new PlayListItem("", "", 1000L, true);mLyric = new Lyric(new File("/sdcard/M0005044007.lrc"), pli);list = mLyric.list;mPaint = new Paint();mPaint.setAntiAlias(true);mPaint.setTextSize(20);mPaint.setTypeface(Typeface.SERIF);mPath = new Path();makePath(mPath);mPathPaint = new Paint();mPathPaint.setAntiAlias(true);mPathPaint.setColor(0x800000FF);mPathPaint.setStyle(Paint.Style.STROKE);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);canvas.drawColor(Color.WHITE);Paint p = mPaint;float x = mX;float plus =currentDunringTime==0?index*30: index*30 +(((float)currentTime - (float)sentenctTime)/(float)currentDunringTime)*(float)30;float y = mY- plus+mTouchCurrY - mTouchStartY+mTouchHistoryY;canvas.translate(0,y);for (int i = 0; i < index; i++) {String text = list.get(i).getContent();if((y+i*30)<=middleY&&(y+i*30+30)>=middleY)middleContent = text;p.setTextAlign(Paint.Align.CENTER);canvas.drawText(text, x, 0, p);// mY- mY/lines*(index - i)canvas.translate(0, DY);}}@Overrideprotected 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 screenmY = h;middleY = h*0.5f;}@Overridepublic boolean onTouchEvent(MotionEvent event) {float y = event.getY();switch (event.getAction()) {case MotionEvent.ACTION_DOWN:mTouchHistoryY += mTouchCurrY - mTouchStartY;mTouchStartY =mTouchCurrY= y;invalidate();break;case MotionEvent.ACTION_MOVE:mTouchCurrY = y;invalidate();break;case MotionEvent.ACTION_UP:Log.v("Lyric content", middleContent.length()+"");CharSequence chars = new CharSequence(){@Overridepublic char charAt(int index) {// TODO Auto-generated method stubreturn middleContent.charAt(index);}@Overridepublic int length() {// TODO Auto-generated method stubreturn middleContent.length();}@Overridepublic CharSequence subSequence(int start, int end) {// TODO Auto-generated method stubreturn middleContent.subSequence(start, end);}@Overridepublic String toString(){return middleContent;}};Toast toast = Toast.makeText(SampleView.this.getContext(),chars, 1000);toast.show();invalidate();break;}return true;}public void updateIndex(long time) {this.currentTime = time;index = mLyric.getNowSentenceIndex(time);Sentence sen = list.get(index);currentDunringTime = sen.getDuring();sentenctTime = sen.getFromTime();}} 3 楼 piaozhiye 2011-04-12 突出显示当前进度的歌词段，并保证该歌词段处于布局中心 。这个怎么实现呢？