android viewpager 图片轮播 实例下载(焦点图)

【实例截图】

【核心代码】

package com.example.viewpagerdemo;

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

import android.os.Bundle;
import android.os.Parcelable;
import android.app.Activity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;

public class MainActivity extends Activity implements OnPageChangeListener {
	private ViewPager viewPager;
	private ArrayList<View> list;
	private ImageView imageView;
	private ImageView[] imageViews;
	private ViewGroup  group;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		LayoutInflater inflater = getLayoutInflater();
		list = new ArrayList<View>();
//		list.add(inflater.inflate(R.layout.item01, null));
//		list.add(inflater.inflate(R.layout.item02, null));
//		list.add(inflater.inflate(R.layout.item03, null));
//		list.add(inflater.inflate(R.layout.item04, null));
//		list.add(inflater.inflate(R.layout.item05, null));
		
		
		imageViews = new ImageView[list.size()];
		
	    ViewGroup group = (ViewGroup)findViewById(R.id.viewGroup);
	    viewPager = (ViewPager)findViewById(R.id.viewPager);
	    
	    for(int i=0; i<list.size(); i  ){
	    	imageView = new ImageView(this);
	    	imageView.setLayoutParams(new LayoutParams(12,12));
	    	imageViews[i] = imageView;
	    	if(i == 0){
	    		imageView.setBackgroundResource(R.drawable.page_indicator_focused);
	    	}else{
	    		imageView.setBackgroundResource(R.drawable.page_indicator_unfocused);
	    	}
	    	
	    	 group.addView(imageView);
	    }
	    
	    
	    viewPager.setAdapter(new MyAdapter());
	    viewPager.setOnPageChangeListener(this);
	    viewPager.setCurrentItem(0);
	    
	}

	@Override
	public void onPageScrollStateChanged(int arg0) {
		
	}

	@Override
	public void onPageScrolled(int arg0, float arg1, int arg2) {
		
	}

	@Override
	public void onPageSelected(int arg0) {
		Log.e("log", "你当前选择的是  "   arg0);
		setImageBackground(arg0%list.size());
	}
	
	
	private void setImageBackground( int selectItems){
		for(int i=0; i<imageViews.length; i  ){
			if(i == selectItems){
				imageViews[i].setBackgroundResource(R.drawable.page_indicator_focused);
			}else{
				imageViews[i].setBackgroundResource(R.drawable.page_indicator_unfocused);
			}
		}
	}
	
	
	public class MyAdapter extends PagerAdapter{

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

		@Override
		public boolean isViewFromObject(View arg0, Object arg1) {
			return arg0 == arg1;
		}
		
		@Override  
        public int getItemPosition(Object object) {  
            return super.getItemPosition(object);  
        }

		@Override
		public Object instantiateItem(ViewGroup container, int position) {
			 ((ViewPager) container).addView(list.get(position%list.size()),0);  
			return list.get(position%list.size());
		}  
		
		
	     @Override  
        public void restoreState(Parcelable arg0, ClassLoader arg1) {  
  
        }  
  
        @Override  
        public Parcelable saveState() {  
            return null;  
        }  
  
        @Override  
        public void startUpdate(View arg0) {  
  
        }  
  
        @Override  
        public void finishUpdate(View arg0) {  
  
        }


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


}