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：

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]);    }}

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;    }}

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。