android banner如何实现无限滚动

要实现Android中的无限滚动广告栏，可以使用ViewPager和FragmentPagerAdapter来实现。下面是一个简单的示例代码：

1. 创建一个BannerFragment用于显示广告内容：

public class BannerFragment extends Fragment {          private int[] images = {R.drawable.image1, R.drawable.image2, R.drawable.image3};     private int currentPosition = 0;      @Nullable     @Override     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {         View view = inflater.inflate(R.layout.fragment_banner, container, false);                  ImageView imageView = view.findViewById(R.id.banner_image);         imageView.setImageResource(images[currentPosition]);                  return view;     }          public void nextBanner() {         currentPosition++;         if (currentPosition >= images.length) {             currentPosition = 0;         }                  ImageView imageView = getView().findViewById(R.id.banner_image);         imageView.setImageResource(images[currentPosition]);     } } 

2. 创建一个BannerAdapter用于管理BannerFragment：

public class BannerAdapter extends FragmentPagerAdapter {      public BannerAdapter(FragmentManager fm) {         super(fm);     }      @Override     public Fragment getItem(int position) {         return new BannerFragment();     }          @Override     public int getCount() {         return Integer.MAX_VALUE;     } } 

3. 在MainActivity中设置ViewPager和BannerAdapter：

public class MainActivity extends AppCompatActivity {      private ViewPager viewPager;     private BannerAdapter bannerAdapter;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          viewPager = findViewById(R.id.view_pager);         bannerAdapter = new BannerAdapter(getSupportFragmentManager());         viewPager.setAdapter(bannerAdapter);          // 设置一个定时器来轮播广告         Timer timer = new Timer();         timer.schedule(new TimerTask() {             @Override             public void run() {                 runOnUiThread(new Runnable() {                     @Override                     public void run() {                         int currentItem = viewPager.getCurrentItem();                         viewPager.setCurrentItem(currentItem + 1);                     }                 });             }         }, 0, 3000);     } } 

这样就可以实现一个简单的无限滚动广告栏，通过不断切换ViewPager的当前项来实现无限滚动效果。