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。