Android实现歌词滚动效果

本文实例为大家分享了Android实现歌词滚动效果的具体代码，供大家参考，具体内容如下

自定义TextView

public class VerticalScrollTextView extends TextView {
 private Paint mPaint;
 private float mX;
 private Paint mPathPaint;
 public int index = 0;
 private List<Sentence> list;
 public float mTouchHistoryY;
 private int mY;
 private float middleY;//
 private static final int DY = 40; //
 public VerticalScrollTextView(Context context) {
  super(context);
  init();
 }
 public VerticalScrollTextView(Context context, AttributeSet attr) {
  super(context, attr);
  init();
 }
 public VerticalScrollTextView(Context context, AttributeSet attr, int i) {
  super(context, attr, i);
  init();
 }
 private void init() {
  setFocusable(true);
  if(list==null){
   list=new ArrayList<Sentence>();
   Sentence sen=new Sentence(0," ");
   list.add(0, sen);
  }  

  //
  mPaint = new Paint();
  mPaint.setAntiAlias(true);
  mPaint.setTextSize(24);
  mPaint.setColor(Color.BLACK);
  mPaint.setAlpha(80);
  mPaint.setTypeface(Typeface.SERIF);

  //
  mPathPaint = new Paint();
  mPathPaint.setAntiAlias(true);
  mPathPaint.setColor(Color.RED);
  mPathPaint.setTextSize(24);
  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.LEFT);
  if (index == -1)
   return;
  p2.setTextAlign(Paint.Align.LEFT);
  //
  canvas.drawText(list.get(index).getName(), mX, middleY, p2);
  float tempY = middleY;
  //
  for (int i = index - 1; i >= 0; i--) {
   tempY = tempY - DY;
   if (tempY < 0) {
    break;
   }
   canvas.drawText(list.get(i).getName(), mX, tempY, p);
  }
  tempY = middleY;
  //
  for (int i = index + 1; i < list.size(); i++) {
   //
   tempY = tempY + DY;
   if (tempY > mY) {
    break;
   }
   canvas.drawText(list.get(i).getName(), mX, tempY, p);
  }
 }
 protected void onSizeChanged(int w, int h, int ow, int oh) {
  super.onSizeChanged(w, h, ow, oh);
  mX = w * 0.3f;
  mY = h;
  middleY = h * 0.5f;
 }

 public long updateIndex(int index) {
  if (index == -1)
   return -1;
  this.index=index;
  return index;
 }

 public List<Sentence> getList() {
  return list;
 }

 public void setList(List<Sentence> list) {
  this.list = list;
 }
 public void updateUI(){
  new Thread(new updateThread()).start();
 }
 class updateThread implements Runnable {
  long time = 300;
  int i=0;
  public void run() {
   while (true) {
    long sleeptime = updateIndex(i);
    time += sleeptime;
    mHandler.post(mUpdateResults);
    if (sleeptime == -1)
     return;
    try {
     Thread.sleep(time);
     i++;
     if(i==getList().size())
      {
       i=0;
       time = 300;
      }
    } catch (InterruptedException e) {
     e.printStackTrace();
    }
   }
  }
 }
 Handler mHandler = new Handler();
 Runnable mUpdateResults = new Runnable() {
  public void run() {
   invalidate(); //
  }
 };
}

数据封装类

public class Sentence {

 private String name;
 private int index;

 public Sentence(int index,String name){
  this.name=name;
  this.index=index;
 }

 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

 public int getIndex() {
  return index;
 }

 public void setIndex(int index) {
  this.index = index;
 }

}

布局

<com.mypackager.ui.VerticalScrollTextView
   android:id="@+id/scoll_textView"
   android:layout_width="500dp"
   android:layout_height="500dp"
   android:text="@string/company_intrduce_text"
   android:visibility="gone"
   ></com.mypackager.VerticalScrollTextView>

Activity代码

List lst=new ArrayList<Sentence>();
   for(int i=0;i<8;i++){
    if(i%2==0){
     Sentence sen=new Sentence(i,i+1+"NanJINGXIXI");
     lst.add(i, sen);
    }else{
     Sentence sen=new Sentence(i,i+1+"Hello world!");
     lst.add(i, sen);
    }
   } 

   play_textView.setList(lst);

   play_textView.updateUI(); 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。