Android实现图片自动切换

在Android中图片的自动切换不仅可以实现自动切换，而且还可以使用手动切换。而且一般在切换的时候，在图片下方还带有其他内容的切换，用来标记是第几个图片的切换。
实现效果如下：

具体的示例代码如下：
布局代码：

</ScrollView

dot_focus.xml文件代码如下：

dot_nORMal.xml文件代码如下：

Activity代码：

public class MainActivity extends AppCompatActivity {
    private ArrayList imageViews= new ArrayList();
    private ArrayListdots=new ArrayList();
    private ViewPager vp;
    private int image[]={R.drawable.denglu,R.drawable.disanye,R.drawable.hhh};
    private int oldPosition=0;
    private int currentItem;
    private ScheduledExecutorService scheduledExecutorService;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取图片资源
        for (int i=0;i<image.length;i++){
            ImageView imageView=new ImageView(this);
            imageView.setImageResource(image[i]);
            imageViews.add(imageView);
        }
       //显示的点的集合
        dots.add(findViewById(R.id.p1));
        dots.add(findViewById(R.id.p2));
        dots.add(findViewById(R.id.p3));
        vp=findViewById(R.id.viewContent);
        vp.setAdapter(new ViewPagerAdapter());
        vp.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }
            @Override
            public void onPageSelected(int position) {
                //点的效果切换
                dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal);
                dots.get(position).setBackgroundResource(R.drawable.dot_fouced);
                oldPosition=position;
                currentItem=position;
            }
            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });
    }
    class ViewPagerAdapter extends PagerAdapter {
        @Override
        public int getCount() {
            return imageViews.size();
        }
        @Override
        public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
            return view==object;
        }
        @Override
        public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
            View v=imageViews.get(position);
            container.removeView(v);
        }
        @NonNull
        @Override
        public Object instantiateItem(@NonNull ViewGroup container, int position) {
            View v=imageViews.get(position);
            container.addView(v);
            return v;
        }
    }
    @Override
    protected void onStart() {
        super.onStart();
        scheduledExecutorService= Executors.newSingleThreadScheduledExecutor();
        scheduledExecutorService.scheduleWithFixedDelay(new ViewPagerTask(),2,2, TimeUnit.SECONDS);
    }
    class ViewPagerTask implements Runnable{
        @Override
        public void run() {
            currentItem=(currentItem+1)%image.length;
            handler.obtainMessage().sendToTarget();
        }
    }
    Handler handler=new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            vp.setCurrentItem(currentItem);
        }
    };
}