Android编程实现TextView垂直自动滚动功能【附demo源码下载】

 /**
 * @author xushilin
 *
 * 垂直滚动的TextView Widget
 */
public class VerticalScrollTextView extends TextView

 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);
  //这里主要处理如果没有传入内容显示的默认值
  if(list==null){
   list=new ArrayList<Notice>();
   Notice sen=new Notice(0,"暂时没有通知公告");
   list.add(0, sen);
  }
  //普通文字的字号，以及画笔颜色的设置
  mPaint = new Paint();
  mPaint.setAntiAlias(true);
  mPaint.setTextSize(16);
  mPaint.setColor(Color.BLACK);
  mPaint.setTypeface(Typeface.SERIF);
  //高亮文字的字号，以及画笔颜色的设置
  mPathPaint = new Paint();
  mPathPaint.setAntiAlias(true);
  mPathPaint.setColor(Color.RED);
  mPathPaint.setTextSize(16);
  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);
   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 * 0.5f;
  mY = h;
  middleY = h * 0.5f;
 }
  private long updateIndex(int index) {
  if (index == -1)
   return -1;
  this.index=index;
  return index;
 }

 public void updateUI(){
  new Thread(new updateThread()).start();
 }
  class updateThread implements Runnable {
  long time = 1000;
  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;
    } catch (InterruptedException e) {
     e.printStackTrace();
    }
   }
  }
 }
 Handler mHandler = new Handler();
 Runnable mUpdateResults = new Runnable() {
  public void run() {
   invalidate();
  }
 };

<?xml version="1.0" encoding="utf-8"?>
<!-- Demonstrates scrolling with a ScrollView. -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical">
 <com.demo.xsl.text.SampleView
 android:id="@+id/sampleView1"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:background="@drawable/selector"
 />
</LinearLayout>

package com.demo.xsl.text;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
 public class VerticalScrollTextActivity extends Activity {
  SampleView mSampleView;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  mSampleView = (SampleView) findViewById(R.id.sampleView1);
  List lst=new ArrayList<Sentence>();
  for(int i=0;i<30;i++){
   if(i%2==0){
    Sentence sen=new Sentence(i,i+"、金球奖三甲揭晓 C罗梅西哈维入围 ");
    lst.add(i, sen);
   }else{
    Sentence sen=new Sentence(i,i+"、公牛欲用三大主力换魔兽？？？？");
    lst.add(i, sen);
   }
  }
  //给View传递数据
  mSampleView.setList(lst);
  //更新View
  mSampleView.updateUI();
 }
}