Android中在fragment中自动轮播图片的主要代码

以下是一个在fragment中自动轮播图片的示例代码：

public class BannerFragment extends Fragment {

    private ViewPager mViewPager;
    private List<Integer> mImageList;
    private int mCurrentPage = 0;
    private Timer mTimer;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_banner, container, false);
        mViewPager = (ViewPager) view.findViewById(R.id.view_pager);
        mImageList = new ArrayList<>();
        mImageList.add(R.drawable.image1);
        mImageList.add(R.drawable.image2);
        mImageList.add(R.drawable.image3);
        mViewPager.setAdapter(new BannerPagerAdapter());
        startAutoPlay();
        return view;
    }

    private void startAutoPlay() {
        mTimer = new Timer();
        mTimer.schedule(new TimerTask() {
            @Override
            public void run() {
                getActivity().runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if (mCurrentPage == mImageList.size()) {
                            mCurrentPage = 0;
                        }
                        mViewPager.setCurrentItem(mCurrentPage++, true);
                    }
                });
            }
        }, 3000, 3000);
    }

    private class BannerPagerAdapter extends PagerAdapter {

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

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

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            ImageView imageView = new ImageView(getActivity());
            imageView.setImageResource(mImageList.get(position));
            container.addView(imageView);
            return imageView;
        }

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

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mTimer != null) {
            mTimer.cancel();
        }
    }
}

这个示例代码中使用了ViewPager和一个Timer来实现自动轮播，每隔3秒钟就会自动切换到下一张图片。PagerAdapter的作用是为ViewPager提供数据源。在onCreateView方法中，我们创建了一个BannerPagerAdapter，然后将其设置给ViewPager。最后在onDestroy方法中，我们取消了Timer的计时任务，以免内存泄漏。