android播放器实现歌词显示功能

网上android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：

播放器的歌词界面实现以下几个功能

• 根据歌曲的播放进度自下而上滚动；

• 提供上下拖动调整歌曲进度的功能；

• 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
  

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

Java代码

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;

@Override
 protected 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
   }
 };

@Override
 public 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

Java代码

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);
   }

@Override
   protected 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);
     }
   }

@Override
   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;
   }

@Override
   public 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(){

@Override
         public char charAt(int index) {
           // TODO Auto-generated method stub
           return middleContent.charAt(index);
         }

@Override
         public int length() {
           // TODO Auto-generated method stub
           return middleContent.length();
         }

@Override
         public CharSequence subSequence(int start, int end) {
           // TODO Auto-generated method stub
           return middleContent.subSequence(start, end);
         }
         @Override
         public 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();
   }
 }

来源：http://ishelf.iteye.com/blog/740402