ViewPager实现图片轮翻效果

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1. import java.util.ArrayList;  

1. import java.util.concurrent.Executors;  

1. import java.util.concurrent.ScheduledExecutorService;  

1. import java.util.concurrent.TimeUnit;  

1. import android.app.Activity;  

1. import android.os.Bundle;  

1. import android.os.Handler;  

1. import android.os.Message;  

1. import android.support.v4.view.PagerAdapter;  

1. import android.support.v4.view.ViewPager;  

1. import android.support.v4.view.ViewPager.OnPageChangeListener;  

1. import android.view.View;  

1. import android.view.ViewGroup;  

1. import android.widget.ImageView;  

1. import android.widget.TextView;  

1. public class MainActivity extends Activity {  

1.     private int imageIds[];  

1.     private String[] titles;  

1.     private ArrayList<ImageView> images;  

1.     private ArrayList<View> dots;  

1.     private TextView title;  

1.     private ViewPager mViewPager;  

1.     private ViewPagerAdapter adapter;  

1.     private int oldPosition = 0;//记录上一次点的位置  

1.     private int currentItem; //当前页面  

1.     private ScheduledExecutorService scheduledExecutorService;  

1.     @Override  

1.     public void onCreate(Bundle savedInstanceState) {  

1.         super.onCreate(savedInstanceState);  

1.         setContentView(R.layout.activity_main);  

1.         //图片ID  

1.         imageIds = new int[]{  

1.             R.drawable.a,     

1.             R.drawable.b,     

1.             R.drawable.c,     

1.             R.drawable.d,     

1.             R.drawable.e      

1.         };  

1.         //图片标题  

1.         titles = new String[]{  

1.             "巩俐不低俗，我就不能低俗",   

1.             "扑树又回来啦！再唱经典老歌引万人大合唱",    

1.             "揭秘北京电影如何升级",     

1.             "乐视网TV版大派送",      

1.             "热血屌丝的反杀"  

1.         };  

1.         //显示的图片  

1.         images = new ArrayList<ImageView>();  

1.         for(int i =0; i < imageIds.length; i++){  

1.             ImageView imageView = new ImageView(this);  

1.             imageView.setBackgroundResource(imageIds[i]);  

1.             images.add(imageView);  

1.         }  

1.         //显示的点  

1.         dots = new ArrayList<View>();  

1.         dots.add(findViewById(R.id.dot_0));  

1.         dots.add(findViewById(R.id.dot_1));  

1.         dots.add(findViewById(R.id.dot_2));  

1.         dots.add(findViewById(R.id.dot_3));  

1.         dots.add(findViewById(R.id.dot_4));  

1.         title = (TextView) findViewById(R.id.title);  

1.         title.setText(titles[0]);  

1.         mViewPager = (ViewPager) findViewById(R.id.vp);  

1.         adapter = new ViewPagerAdapter();   

1.         mViewPager.setAdapter(adapter);  

1.         mViewPager.setOnPageChangeListener(new OnPageChangeListener() {  

1.             @Override  

1.             public void onPageSelected(int position) {  

1.                 title.setText(titles[position]);  

1.                 dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal);  

1.                 dots.get(position).setBackgroundResource(R.drawable.dot_focused);  

1.                 oldPosition = position;  

1.                 currentItem = position;  

1.             }  

1.             @Override  

1.             public void onPageScrolled(int arg0, float arg1, int arg2) {  

1.             }  

1.             @Override  

1.             public void onPageScrollStateChanged(int arg0) {  

1.             }  

1.         });  

1.     }  

1.     private class ViewPagerAdapter extends PagerAdapter {  

1.         @Override  

1.         public int getCount() {  

1.             return images.size();  

1.         }  

1.         //是否是同一张图片  

1.         @Override  

1.         public boolean isViewFromObject(View arg0, Object arg1) {  

1.             return arg0 == arg1;  

1.         }  

1.         @Override  

1.         public void destroyItem(ViewGroup view, int position, Object object) {  

1.             view.removeView(images.get(position));  

1.         }  

1.         @Override  

1.         public Object instantiateItem(ViewGroup view, int position) {  

1.             view.addView(images.get(position));  

1.             return images.get(position);  

1.         }  

1.     }  

1.     @Override  

1.     protected void onStart() {  

1.         // TODO Auto-generated method stub  

1.         super.onStart();  

1.         scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();  

1.         //每隔2秒钟切换一张图片  

1.         scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(), 2, 2, TimeUnit.SECONDS);  

1.     }  

1.     //切换图片  

1.     private class ViewPagerTask implements Runnable {  

1.         @Override  

1.         public void run() {  

1.             currentItem = (currentItem +1) % imageIds.length;  

1.             //更新界面  

1.             handler.obtainMessage().sendToTarget();  

1.         }  

1.     }  

1.     private Handler handler = new Handler(){  

1.         @Override  

1.         public void handleMessage(Message msg) {  

1.             //设置当前页面  

1.             mViewPager.setCurrentItem(<span style="font-family: Arial, Helvetica, sans-serif;">currentItem</span><span style="font-family: Arial, Helvetica, sans-serif;">);</span>  

1.         }  

1.     };  

1. }