ViewPager无限轮播，简单实现

//不墨迹，直接上

public class PagerAdapter extends android.support.v4.view.PagerAdapter {    private List<pagerData> viewlist;    private Context context;    public PagerAdapter(Context context,List<pagerData> viewlist) {        this.viewlist = viewlist;        this.context=context;    }    @Override    public int getCount() {        return Integer.MAX_VALUE;    }    @Override    public boolean isViewFromObject(View view, Object object) {        return view==object;    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {    }    @Override    public Object instantiateItem(ViewGroup container, int position) {        View view = View.inflate(context, R.layout.tulayout, null);        ImageView ggtv =(ImageView) view.findViewById(R.id.imageView);        //对ViewPager页号求模取出View列表中要显示的项        position %= viewlist.size();        if (position<0){            position = viewlist.size()+position;        }        pagerData data = viewlist.get(position);        ggtv.setImageResource(data.getData());        container.addView(view);        return view;    }}

public class Main2Activity extends AppCompatActivity {    private ViewPager vp;    private LinearLayout ll_dots;    private ArrayList<ImageView> dotsList;    private List<pagerData> pagerlist;    Handler handler=new Handler(){        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            if(msg.what==1){                int db = vp.getCurrentItem();                db++;                vp.setCurrentItem(db);            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main2);        vp=(ViewPager)findViewById(R.id.vp);        ll_dots=(LinearLayout)findViewById(R.id.lllllll);        pagerlist=new ArrayList<>();        pagerlist.add(new pagerData(R.drawable.aaa));        pagerlist.add(new pagerData(R.drawable.bbb));        pagerlist.add(new pagerData(R.drawable.ccc));        pagerlist.add(new pagerData(R.drawable.ddd));        vp.setAdapter(new PagerAdapter(this,pagerlist));        vp.setCurrentItem(pagerlist.size()*100);        initDots();        vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {                //遍历存放图片的数组                for (int i = 0; i < pagerlist.size(); i++) {                    //判断小点点与当前的图片是否对应，对应设置为亮色 ，否则设置为暗色                    if (i == position % pagerlist.size()) {                        dotsList.get(i).setImageDrawable(getResources().getDrawable(R.drawable.yuandiana));                    } else {                        dotsList.get(i).setImageDrawable(getResources().getDrawable(R.drawable.yuandianb));                    }                }            }            @Override            public void onPageSelected(int position) {            }            @Override            public void onPageScrollStateChanged(int state) {            }        });//        为了简单，这里选择了休眠        new Thread(){            @Override            public void run() {                super.run();                while (true){                    try {                        sleep(3000);                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                    handler.sendEmptyMessage(1);                }            }        }.start();//        添加点击事件        vp.setOnTouchListener(new View.OnTouchListener() {            int touchFlag = 0;            float x = 0, y = 0;            @Override            public boolean onTouch(View view, MotionEvent motionEvent) {                ViewConfiguration configuration = ViewConfiguration.get(Main2Activity.this);                int mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);                switch (motionEvent.getAction()) {                    case MotionEvent.ACTION_DOWN:                        touchFlag = 0;                        x = motionEvent.getX();                        y = motionEvent.getY();                        break;                    case MotionEvent.ACTION_MOVE:                        float xDiff = Math.abs(motionEvent.getX() - x);                        float yDiff = Math.abs(motionEvent.getY() - y);                        if (xDiff < mTouchSlop && xDiff >= yDiff)                            touchFlag = 0;                        else                            touchFlag = -1;                        break;                    case MotionEvent.ACTION_UP:                        if (touchFlag == 0) {                            int item = vp.getCurrentItem();                            int a = pagerlist.size();                            for(int i=0;i<a;i++){                                int b = item%a;                                Intent intent=new Intent(Main2Activity.this,MainActivity.class);//                                int ids = pagerlist.get(b).getData();//                                intent.putExtra("id",id);                                startActivity(intent);                                break;                            }                        }                        break;                }                return false;            }        });    }    private void initDots() {        //创建存放小点点的集合        dotsList = new ArrayList<ImageView>();        //每次初始化之前清空集合        dotsList.clear();        // 每次初始化之前  移除  布局中的所有小点        ll_dots.removeAllViews();        for (int i = 0; i < pagerlist.size(); i++) {            //创建小点点图片            ImageView imageView = new ImageView(this);            Drawable drawable = null;            if (i == 0) {                // 亮色图片                drawable = getResources().getDrawable(R.drawable.yuandiana);            } else {                drawable = getResources().getDrawable(R.drawable.yuandianb);            }            imageView.setImageDrawable(drawable);            // 考虑屏幕适配            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(dip2px(this, 10), dip2px(this, 10));            //设置小点点之间的间距            params.setMargins(dip2px(this, 5), 0, dip2px(this, 5), 0);            //将小点点添加大线性布局中            ll_dots.addView(imageView, params);            // 将小点的控件添加到集合中            dotsList.add(imageView);        }    }    /**     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)     */    public int dip2px(Context context, float dpValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (dpValue * scale + 0.5f);    }}