android图片轮播

第一步，先写布局文件

 <com.main.util.SlideShowView
                 android:id="@+id/slideshowView"
                 android:layout_width="fill_parent"
                 android:layout_height="300dp"
                 android:layout_centerHorizontal="true"
                 />

第二步，java代码

 package com.main.util;

 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;

 import com.main.R;

 import android.content.Context;
 import android.graphics.drawable.Drawable;
 import android.os.Handler;
 import android.os.Message;
 import android.os.Parcelable;
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.ViewPager;
 import android.support.v4.view.ViewPager.OnPageChangeListener;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.ImageView.ScaleType;


 public class SlideShowView extends FrameLayout {
     //轮播图图片数量
     private final static int IMAGE_COUNT = 5;
     //自动轮播的时间间隔
     private final static int TIME_INTERVAL = 5;
     //自动轮播启用开关
     private final static boolean isAutoPlay = true;

     //自定义轮播图的资源ID
     private int[] imagesResIds;
     //放轮播图片的ImageView 的list
     private List<ImageView> imageViewsList;
     //放圆点的View的list
     private List<View> dotViewsList;

     private ViewPager viewPager;
     //当前轮播页
     private int currentItem  = 0;
     //定时任务
     private ScheduledExecutorService scheduledExecutorService;
     //Handler
     private Handler handler = new Handler(){

         @Override
         public void handleMessage(Message msg) {
             // TODO Auto-generated method stub
             super.handleMessage(msg);
             viewPager.setCurrentItem(currentItem);
         }

     };

     public SlideShowView(Context context) {
         this(context,null);
         // TODO Auto-generated constructor stub
     }
     public SlideShowView(Context context, AttributeSet attrs) {
         this(context, attrs, 0);
         // TODO Auto-generated constructor stub
     }
     public SlideShowView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         // TODO Auto-generated constructor stub
         initData();
         initUI(context);
         if(isAutoPlay){
             startPlay();
         }

     }
     /**
      * 开始轮播图切换
      */
     private void startPlay(){
         scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
         scheduledExecutorService.scheduleAtFixedRate(new SlideShowTask(), 1, 4, TimeUnit.SECONDS);
     }
     /**
      * 停止轮播图切换
      */
     private void stopPlay(){
         scheduledExecutorService.shutdown();
     }
     /**
      * 初始化相关Data
      */
     private void initData(){
         imagesResIds = new int[]{//图片数据
                 R.drawable.p1,
                 R.drawable.p2,
         };
         imageViewsList = new ArrayList<ImageView>();
         dotViewsList = new ArrayList<View>();

     }
     /**
      * 初始化Views等UI
      */
     private void initUI(Context context){
         LayoutInflater.from(context).inflate(R.layout.imageviewpager, this, true);
         for(int imageID : imagesResIds){
             ImageView view =  new ImageView(context);
             view.setImageResource(imageID);
             view.setScaleType(ScaleType.FIT_XY);
             imageViewsList.add(view);
         }
         dotViewsList.add(findViewById(R.id.v_dot1));
         dotViewsList.add(findViewById(R.id.v_dot2));

         viewPager = (ViewPager) findViewById(R.id.viewPager);
         viewPager.setFocusable(true);

         viewPager.setAdapter(new MyPagerAdapter());
         viewPager.setOnPageChangeListener(new MyPageChangeListener());
     }

     /**
      * 填充ViewPager的页面适配器
      * @author caizhiming
      */
     private class MyPagerAdapter  extends PagerAdapter{

         @Override
         public void destroyItem(View container, int position, Object object) {
             // TODO Auto-generated method stub
             //((ViewPag.er)container).removeView((View)object);
             ((ViewPager)container).removeView(imageViewsList.get(position));
         }

         @Override
         public Object instantiateItem(View container, int position) {
             // TODO Auto-generated method stub
             ((ViewPager)container).addView(imageViewsList.get(position));
             return imageViewsList.get(position);
         }

         @Override
         public int getCount() {
             // TODO Auto-generated method stub
             return imageViewsList.size();
         }

         @Override
         public boolean isViewFromObject(View arg0, Object arg1) {
             // TODO Auto-generated method stub
             return arg0 == arg1;
         }
         @Override
         public void restoreState(Parcelable arg0, ClassLoader arg1) {
             // TODO Auto-generated method stub

         }

         @Override
         public Parcelable saveState() {
             // TODO Auto-generated method stub
             return null;
         }

         @Override
         public void startUpdate(View arg0) {
             // TODO Auto-generated method stub

         }

         @Override
         public void finishUpdate(View arg0) {
             // TODO Auto-generated method stub

         }

     }
     /**
      * ViewPager的监听器
      * 当ViewPager中页面的状态发生改变时调用
      * @author caizhiming
      */
     private class MyPageChangeListener implements OnPageChangeListener{

         boolean isAutoPlay = false;

         @Override
         public void onPageScrollStateChanged(int arg0) {
             // TODO Auto-generated method stub
             switch (arg0) {
             case 1:// 手势滑动，空闲中
                 isAutoPlay = false;
                 break;
             case 2:// 界面切换中
                 isAutoPlay = true;
                 break;
             case 0:// 滑动结束，即切换完毕或者加载完毕
                 // 当前为最后一张，此时从右向左滑，则切换到第一张
                 if (viewPager.getCurrentItem() == viewPager.getAdapter().getCount() - 1 && !isAutoPlay) {
                     viewPager.setCurrentItem(0);
                 }
                 // 当前为第一张，此时从左向右滑，则切换到最后一张
                 else if (viewPager.getCurrentItem() == 0 && !isAutoPlay) {
                     viewPager.setCurrentItem(viewPager.getAdapter().getCount() - 1);
                 }
                 break;
         }
         }

         @Override
         public void onPageScrolled(int arg0, float arg1, int arg2) {
             // TODO Auto-generated method stub

         }

         @Override
         public void onPageSelected(int pos) {
             // TODO Auto-generated method stub

             currentItem = pos;
             for(int i=0;i < dotViewsList.size();i++){
                 if(i == pos){
                     ((View)dotViewsList.get(pos)).setBackgroundResource(R.drawable.dot_black);
                 }else {
                     ((View)dotViewsList.get(i)).setBackgroundResource(R.drawable.dot_white);
                 }
             }
         }

     }

     /**
      *执行轮播图切换任务
      *@author caizhiming
      */
     private class SlideShowTask implements Runnable{

         @Override
         public void run() {
             // TODO Auto-generated method stub
             synchronized (viewPager) {
                 currentItem = (currentItem+1)%imageViewsList.size();
                 handler.obtainMessage().sendToTarget();
             }
         }

     }
     /**
      * 销毁ImageView资源，回收内存
      * @author caizhiming
      */
     private void destoryBitmaps() {

         for (int i = 0; i < IMAGE_COUNT; i++) {
             ImageView imageView = imageViewsList.get(i);
             Drawable drawable = imageView.getDrawable();
             if (drawable != null) {
                 //解除drawable对view的引用
                 drawable.setCallback(null);
             }
         }
     }

 }