Android实现自动播放图片功能

package com.example.week4_day4_viewpager2;  import java.util.ArrayList; import java.util.List;  import android.R.integer; import android.os.Bundle; import android.os.Handler; import android.app.Activity; import android.support.v4.view.ViewPager; import android.view.Menu; import android.widget.ImageView;  public class MainActivity extends Activity {    private ViewPager viewPager;   // 数据源   private int[] images = { R.drawable.image1, R.drawable.image2,       R.drawable.image3 };   // 存放数据源的集合   List<ImageView> list;    @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     viewPager = (ViewPager) findViewById(R.id.viewpager);     // 实例化list     list = new ArrayList<ImageView>();     for (int i = 0; i < images.length; i++) {       ImageView imageView = new ImageView(MainActivity.this);       imageView.setImageResource(images[i]);       list.add(imageView);     }     // 绑定适配器     viewPager.setAdapter(new MyViewPagerAdapter(MainActivity.this, list));     // 当有3张图片时,走到id=2时最后一张,     viewPager.setCurrentItem(Integer.MAX_VALUE / 2 - Integer.MAX_VALUE / 2         % list.size());// 假设viewPager有无数条数据     // 延迟两秒发送一条消息     handler.sendEmptyMessageDelayed(1, 2000);   }    // 让图片自动播放,无限循环   private Handler handler = new Handler() {     public void handleMessage(android.os.Message msg) {       /**        * 第一种方法,播放到最后一张时,回退到第一张照片从头播放        *       弊端:回退时如果图片过多,会出现回退重影,即3张时,从最后一张瞬间回退到第2张,又瞬间回退到第1张        */ //      int i = viewPager.getCurrentItem();// 当前item //      if (i == list.size() - 1) {// 如果第一条等于最后一条 //      // false:是否显示动画 //      viewPager.setCurrentItem(0, true);// 回到第一条item //      } else { //      viewPager.setCurrentItem(i + 1, true); //      }       /**        * 第二种方法,无限循环播放,每次都把所有相片,放到后面查看        */       viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);        sendEmptyMessageDelayed(1, 2000);     };   }; } 

package com.example.week4_day4_viewpager2;  import java.util.List;  import android.content.Context; import android.support.v4.view.PagerAdapter; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView;  public class MyViewPagerAdapter extends PagerAdapter{    private Context context;   private List<ImageView> list;      public MyViewPagerAdapter(Context context, List<ImageView> list) {     super();     this.context = context;     this.list = list;   }    @Override   public int getCount() {     // TODO Auto-generated method stub     return Integer.MAX_VALUE;//设置viewPager里有N条数据     //return list.size();   }      @Override   public Object instantiateItem(ViewGroup container, int position) {     //假设有3张照片,走到id=2时,走id=0的,所以取余     container.addView(list.get(position%list.size()));     return list.get(position%list.size());     //return list.get(position);   }   @Override   public void destroyItem(ViewGroup container, int position, Object object) {     // TODO Auto-generated method stub     container.removeView(list.get(position%list.size()));     //container.removeView(list.get(position));     //super.destroyItem(container, position, object);   }    @Override   public boolean isViewFromObject(View arg0, Object arg1) {     // TODO Auto-generated method stub     return arg0==arg1;   }  }  

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:tools="http://schemas.android.com/tools"   android:layout_width="match_parent"   android:layout_height="match_parent"   android:paddingBottom="@dimen/activity_vertical_margin"   android:paddingLeft="@dimen/activity_horizontal_margin"   android:paddingRight="@dimen/activity_horizontal_margin"   android:paddingTop="@dimen/activity_vertical_margin"   tools:context=".MainActivity" >    <android.support.v4.view.ViewPager     android:id="@+id/viewpager"     android:layout_width="match_parent"     android:layout_height="match_parent"    />  </RelativeLayout>