用最简单最实用的方式实现ViewPager无限循环两种方式

    先上效果：

                                

第一种：

实现原理 ：

              有三张图片，实现无限循环。在viewpager中设置5个view，第一个为三张图片的最后一张，第五张为三张图片的第一张。图片顺序如下数字：

                                         2-0-1-2-0

             0-1-2为正常的三个图片。2，0  为添加的两个图片view

滑动的顺序：进入页面显示0图片，向右滑动到0时,将0页设置为0，则可以继续向右滑动。同理当向左滑动到  2 时，将2页设置为2。

下面贴代码：

ViewpagerDemo.java

package com.example.demo;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.os.Bundle;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.support.v4.view.ViewPager.OnPageChangeListener;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;public class ViewpagerDemo extends Activity implements OnPageChangeListener {private ViewPager viewPager;private List<ImageView> listviews;private int[] pics = { R.drawable.xu1, R.drawable.xu2, R.drawable.xu3 };@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.viewpager);viewPager = (ViewPager) findViewById(R.id.viewpager);listviews = new ArrayList<ImageView>();// 添加viewpager多出的两个viewint length = pics.length + 2;for (int i = 0; i < length; i++) {ImageView imageView = new ImageView(ViewpagerDemo.this);ViewGroup.LayoutParams viewPagerImageViewParams = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,ViewGroup.LayoutParams.FILL_PARENT);imageView.setLayoutParams(viewPagerImageViewParams);imageView.setScaleType(ImageView.ScaleType.FIT_XY);listviews.add(imageView);}viewPager.setAdapter(new ViewPagerAdapter());viewPager.setOnPageChangeListener(ViewpagerDemo.this);// 设置viewpager在第二个视图显示viewPager.setCurrentItem(1);}@Overridepublic void onPageScrollStateChanged(int arg0) {}@Overridepublic void onPageScrolled(int arg0, float arg1, int arg2) {}@Overridepublic void onPageSelected(int i) {int pageIndex = i;if (i == 0) {// 当视图在第一个时，将页面号设置为图片的最后一张。pageIndex = pics.length;} else if (i == pics.length + 1) {// 当视图在最后一个是,将页面号设置为图片的第一张。pageIndex = 1;}if (i != pageIndex) {viewPager.setCurrentItem(pageIndex, false);return;}}class ViewPagerAdapter extends PagerAdapter {@Overridepublic void destroyItem(ViewGroup container, int position, Object object) {ImageView view = listviews.get(position);container.removeView(view);view.setImageBitmap(null);}@Overridepublic Object instantiateItem(ViewGroup container, int i) {if (i == 0) {listviews.get(i).setImageResource(pics[2]);} else if (i == (listviews.size() - 1)) {listviews.get(i).setImageResource(pics[0]);} else {listviews.get(i).setImageResource(pics[i - 1]);}container.addView(listviews.get(i));return listviews.get(i);}@Overridepublic int getCount() {return listviews.size();}@Overridepublic boolean isViewFromObject(View view, Object o) {return view == o;}}}

第二种：
实现原理:在适配器中将getcount的值设置为无限大。然后将3份图片加载其中。

package com.example.demo;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.os.Bundle;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewPager;import android.support.v4.view.ViewPager.OnPageChangeListener;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;public class ViewpagerDemo2 extends Activity {private ViewPager viewPager;private List<ImageView> listviews;private int[] pics = { R.drawable.xu1, R.drawable.xu2, R.drawable.xu3 };@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.viewpager);viewPager = (ViewPager) findViewById(R.id.viewpager);listviews = new ArrayList<ImageView>();for (int i = 0; i < pics.length; i++) {ImageView imageView = new ImageView(ViewpagerDemo2.this);ViewGroup.LayoutParams viewPagerImageViewParams = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,ViewGroup.LayoutParams.FILL_PARENT);imageView.setLayoutParams(viewPagerImageViewParams);imageView.setScaleType(ImageView.ScaleType.FIT_XY);imageView.setImageResource(pics[i]);listviews.add(imageView);}viewPager.setAdapter(new ViewPagerAdapter());viewPager.setCurrentItem(499);}class ViewPagerAdapter extends PagerAdapter {@Overridepublic Object instantiateItem(ViewGroup container, int position) {if (listviews.get(position % listviews.size()).getParent() != null) {((ViewPager) listviews.get(position % listviews.size()).getParent()).removeView(listviews.get(position% listviews.size()));}((ViewPager) container).addView(listviews.get(position % listviews.size()), 0);return listviews.get(position % listviews.size());}@Overridepublic int getCount() {return Integer.MAX_VALUE;}@Overridepublic boolean isViewFromObject(View view, Object o) {return view == o;}}}

转载请注明出处：http://blog.csdn.net/just_sanpark/article/details/17436037