Android ViewPager实现Banner循环播放

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:id="@+id/container"
 android:layout_width="match_parent"
 android:layout_height="match_parent" >

 <!-- ViewPager -->
 <android.support.v4.view.ViewPager
  android:id="@+id/viewpager"
  android:layout_width="fill_parent"
  android:layout_height="180dip" />

 <LinearLayout
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_alignBottom="@id/viewpager"
  android:background="#44000000"
  android:gravity="center"
  android:orientation="vertical"
  android:padding="5dip" >

  <!-- Banner的文字描述 -->
  <TextView
   android:id="@+id/tv_banner_text_desc"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:textColor="@android:color/white" />

  <!-- 小圆点的父控件 -->
  <LinearLayout
   android:id="@+id/ll_dot_group"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_gravity="center_horizontal"
   android:layout_marginTop="5dip"
   android:gravity="center_horizontal"
   android:orientation="horizontal" >
  </LinearLayout>
 </LinearLayout>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

 <item android:drawable="@drawable/point_bg_enable" android:state_enabled="true"></item>
 <item android:drawable="@drawable/point_bg_normal" android:state_enabled="false"></item>

</selector>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
 android:shape="oval" >
 <corners android:radius="0.5dip" />
 <solid android:color="#aaFFFFFF" />
</shape>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
 android:shape="oval" >
 <corners android:radius="0.5dip" />
 <solid android:color="#55000000" />
</shape>

package com.owen.adbanner;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.os.SystemClock;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Toast;
import android.widget.LinearLayout.LayoutParams;
import android.widget.TextView;

/**
 * ViewPager实现Banner循环滚动
 * 
 * @author owen
 */
public class MainActivity extends Activity {

 /** ViewPager中ImageView的容器 */
 private List<ImageView> imageViewContainer = null;


 /** 上一个被选中的小圆点的索引，默认值为0 */
 private int preDotPosition = 0;

 /** Banner文字描述数组 */
 private String[] bannerTextDescArray = { 
   "巩俐不低俗，我就不能低俗", 
   "朴树又回来了，再唱经典老歌引万人大合唱",
   "揭秘北京电影如何升级", 
   "乐视网TV版大派送", "热血屌丝的反杀" 
 };

 /** Banner滚动线程是否销毁的标志，默认不销毁 */
 private boolean isStop = false;

 /** Banner的切换下一个page的间隔时间 */
 private long scrollTimeOffset = 5000;

 private ViewPager viewPager;

 /** Banner的文字描述显示控件 */
 private TextView tvBannerTextDesc;

 /** 小圆点的父控件 */
 private LinearLayout llDotGroup;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  initView();
  startBannerScrollThread();
 }

 /**
  * 开启Banner滚动线程
  */
 private void startBannerScrollThread() {
  new Thread(new Runnable() {

   @Override
   public void run() {
    while (!isStop) {
     //每个两秒钟发一条消息到主线程，更新viewpager界面
     SystemClock.sleep(scrollTimeOffset);

     runOnUiThread(new Runnable() {
      public void run() {
       int newindex = viewPager.getCurrentItem() + 1;
       viewPager.setCurrentItem(newindex);
      }
     });
    }
   }
  }).start();
 }

 @Override
 protected void onDestroy() {
  // 销毁线程
  isStop = true;
  super.onDestroy();
 }

 private void initView() {
  viewPager = (ViewPager) findViewById(R.id.viewpager);
  llDotGroup = (LinearLayout) findViewById(R.id.ll_dot_group);
  tvBannerTextDesc = (TextView) findViewById(R.id.tv_banner_text_desc);

  imageViewContainer = new ArrayList<ImageView>();
  int[] imageIDs = new int[] { 
    R.drawable.a, 
    R.drawable.b, 
    R.drawable.c,
    R.drawable.d,
    R.drawable.e, 
  };

  ImageView imageView = null;
  View dot = null;
  LayoutParams params = null;
  for (int id : imageIDs) {
   imageView = new ImageView(this);
   imageView.setBackgroundResource(id);
   imageViewContainer.add(imageView);

   // 每循环一次添加一个点到线行布局中
   dot = new View(this);
   dot.setBackgroundResource(R.drawable.dot_bg_selector);
   params = new LayoutParams(5, 5);
   params.leftMargin = 10;
   dot.setEnabled(false);
   dot.setLayoutParams(params);
   llDotGroup.addView(dot); // 向线性布局中添加"点"
  }

  viewPager.setAdapter(new BannerAdapter());
  viewPager.setOnPageChangeListener(new BannerPageChangeListener());

  // 选中第一个图片、文字描述
  tvBannerTextDesc.setText(bannerTextDescArray[0]);
  llDotGroup.getChildAt(0).setEnabled(true);
  viewPager.setCurrentItem(0);
 }

 /**
  * ViewPager的适配器
  */
 private class BannerAdapter extends PagerAdapter {

  @Override
  public void destroyItem(ViewGroup container, int position, Object object) {
   container.removeView(imageViewContainer.get(position % imageViewContainer.size()));
  }

  @Override
  public Object instantiateItem(ViewGroup container, int position) {
   View view = imageViewContainer.get(position % imageViewContainer.size());

   // 为每一个page添加点击事件
   view.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
     Toast.makeText(MainActivity.this, "Page 被点击了", Toast.LENGTH_SHORT).show();
    }

   });

   container.addView(view);
   return view;
  }

  @Override
  public int getCount() {
   return Integer.MAX_VALUE;
  }

  @Override
  public boolean isViewFromObject(View view, Object object) {
   return view == object;
  }

 }

 /**
  * Banner的Page切换监听器
  */
 private class BannerPageChangeListener implements ViewPager.OnPageChangeListener {

  @Override
  public void onPageScrollStateChanged(int arg0) {
   // Nothing to do
  }

  @Override
  public void onPageScrolled(int arg0, float arg1, int arg2) {
   // Nothing to do
  }

  @Override
  public void onPageSelected(int position) {
   // 取余后的索引，得到新的page的索引
   int newPositon = position % imageViewContainer.size();
   // 根据索引设置图片的描述
   tvBannerTextDesc.setText(bannerTextDescArray[newPositon]);
   // 把上一个点设置为被选中
   llDotGroup.getChildAt(preDotPosition).setEnabled(false);
   // 根据索引设置那个点被选中
   llDotGroup.getChildAt(newPositon).setEnabled(true);
   // 新索引赋值给上一个索引的位置
   preDotPosition = newPositon;
  }

 }

}