viewpager实现自动循环轮播图

android:layout_
android:layout_
tools:cOntext=".MainActivity">

 

 
 

public class MainActivity extends AppCompatActivity {
 private ImageView indicator;//表示圆点指示器
 private ImageView [] indicators;//保存圆点指示器的数组
 private boolean iscOntinue= true;
 private ViewPager viewPager;
 private ViewGroup viewGroup;
 private ArrayList fragments;
 List imgs = null;
 private AtomicInteger index = new AtomicInteger();
 private Handler viewHandler= new Handler(){
 @Override
 public void handleMessage(@NonNull Message msg) {
  super.handleMessage(msg);
  viewPager.setCurrentItem(msg.what);
 }
 };

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 initView();
 }
 public void initView(){
 viewPager=findViewById(R.id.vp_adv);
 viewGroup=findViewById(R.id.View_indicator);
 //四张广告图片加载到集合中进行保存
 List listPics = new ArrayList<>();
 ImageView img1 = new ImageView(this);
 img1.setBackgroundResource(R.mipmap.food1);
 listPics.add(img1);
 ImageView img2 = new ImageView(this);
 img1.setBackgroundResource(R.mipmap.shop2);
 listPics.add(img2);
 ImageView img3 = new ImageView(this);
 img1.setBackgroundResource(R.mipmap.shop3);
 listPics.add(img3);
 ImageView img4 = new ImageView(this);
 img1.setBackgroundResource(R.mipmap.shop4);
 listPics.add(img4);
 initFragments();
 //动态设置四个圆点属性
 indicators = new ImageView[listPics.size()];
 for(int i=0;iindicators.length-1){
  index.getAndAdd(-4);
 }
 try {
  Thread.sleep(2000);
 } catch (InterruptedException e) {
  e.printStackTrace();
 }
 }
 private void initFragments() {
 imgs = new ArrayList();
 imgs.add(R.mipmap.timg1);
 imgs.add(R.mipmap.timg2);
 imgs.add(R.mipmap.timg3);
 imgs.add(R.mipmap.timg4);

 }
 class pagerAdapter extends FragmentPagerAdapter{

 public pagerAdapter(FragmentManager fm) {
  super(fm);
 }

 @Override
 public Fragment getItem(int arg0) {
  //得到要显示的对象并初始化图片
  MyFragment fm = new MyFragment();
  fm.setUrl(imgs.get(arg0));

  return fm;
 }

 @Override
 public int getCount() {
  return imgs.size();
 }

 }
}

class MyPagerAdapter extends PagerAdapter{
 private List viewList;
 public MyPagerAdapter(ListviewList){
 this.viewList = viewList;
 }

 @Override
 public int getCount() {
 return viewList.size();
 }

 @Override
 public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
 return view==object;
 }

 @NonNull
 @Override
 public Object instantiateItem(@NonNull ViewGroup container, int position) {
 container.addView(viewList.get(position));
 return viewList.get(position);
 }

 @Override
 public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
 container.removeView(viewList.get(position));
 }
}