[android] 轮播图-无限循环_app

概述实现无限循环 在getCount()方法中，返回一个很大的值，Integer.MAX_VALUE 在instantiateItem()方法中，获取当前View的索引时，进行取于 *** 作，传递进来的int

实现无限循环

在getCount()方法中，返回一个很大的值，Integer.MAX_VALUE

在instantiateItem()方法中，获取当前VIEw的索引时，进行取于 *** 作，传递进来的int position是个非常大的数，对他进行求余数

在destroyItem()方法中，同样

在onPageSelected()监听方法中，对传递进来的索引进行取于

反向的无限循环

调用VIEwPager对象的setCurrentItem()方法，设置第一次进来时候的当前页，参数：int数字，我们把它定位到Integer.MAX_VALUE的中间，并且保证第一条是当前位置，Integer.MAX_VALUE/2-((Integer.MAX_VALUE/2)%banners.size())

目前有个左划空白页的问题没解决

package com.tsh.myvIEwpager;import java.util.ArrayList; java.util.List; androID.app.Activity; androID.os.Bundle; androID.support.v4.vIEw.PagerAdapter; androID.support.v4.vIEw.VIEwPager; androID.support.v4.vIEw.VIEwPager.OnPagechangelistener; androID.vIEw.VIEw; androID.vIEw.VIEwGroup; androID.Widget.ImageVIEw; androID.Widget.linearLayout; androID.Widget.TextVIEw;public class MainActivity extends Activity {    private VIEwPager vp_banner;     linearLayout ll_points;     TextVIEw tv_Title;    private List<VIEw> banners;    private String[] Titles=new String[]{            "新闻标题1","新闻标题2"    };    private List<ImageVIEw> points=new ArrayList<ImageVIEw>();    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(R.layout.activity_main);        // 初始化        vp_banner = (VIEwPager) findVIEwByID(R.ID.vp_banner);        ll_points = (linearLayout) findVIEwByID(R.ID.ll_points);        tv_Title = (TextVIEw) findVIEwByID(R.ID.tv_Title);                 banner部分        banners = new ArrayList<>();        ImageVIEw img1 = new ImageVIEw(this);        img1.setimageResource(R.drawable.a);        banners.add(img1);        ImageVIEw img2 = );        img2.setimageResource(R.drawable.b);        banners.add(img2);        ImageVIEw img3 = );        img3.setimageResource(R.drawable.c);        banners.add(img3);                小图标        ll_points=(linearLayout) findVIEwByID(R.ID.ll_points);        for(int i=0;i<banners.size();i++){            ImageVIEw image=);            image.setimageResource(R.drawable.point_selector);            linearLayout.LayoutParams params=new linearLayout.LayoutParams(5,5);            params.rightmargin=4;            image.setLayoutParams(params);                        if(i==0){                image.setEnabled(true);            }else{                image.setEnabled(false);            }            points.add(image);            ll_points.addVIEw(image);        }                 设置适配器        vp_banner.setAdapter( MyPagerAdapter());        vp_banner.setCurrentItem(Integer.MAX_VALUE/2-((Integer.MAX_VALUE/2)%banners.size()));        vp_banner.setonPagechangelistener( OnPagechangelistener() {            @OverrIDe            voID onPageSelected(int arg0) {                tv_Title.setText(Titles[arg0%banners.size()]);                小图标处理                for(ImageVIEw point:points){                    point.setEnabled();                }                points.get(arg0%banners.size()).setEnabled();            }                        @OverrIDe            voID onPageScrolled(int arg0,float arg1,1)"> arg2) {                 Todo auto-generated method stub                            }                        @OverrIDe            voID onPageScrollStateChanged( arg0) {                                            }        });            }    private class MyPagerAdapter  PagerAdapter {        @OverrIDe        voID destroyItem(VIEwGroup container,1)"> position,Object object) {            System.out.println("销毁："+position);            container.removeVIEw((VIEw)object);            object=null;        }        @OverrIDe        public Object instantiateItem(VIEwGroup container,1)"> position) {            System.out.println("初始化："+position);            position=position%banners.size();                        解决右划出错            if(banners.get(position).getParent()!=){                container.removeVIEw(banners.get(position));            }{                container.addVIEw(banners.get(position));            }                        return banners.get(position);        }        @OverrIDe         getCount() {             Integer.MAX_VALUE;        }        @OverrIDe        boolean isVIEwFromObject(VIEw arg0,Object arg1) {            return arg0 == arg1;        }    }}