ImageView的圖片輪播實現

要實現ImageView的圖片輪播，可以使用ViewPager和PagerAdapter。以下是一個簡單的示例代碼：

1. 首先，在布局文件中添加ViewPager和指示器：

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <LinearLayout
        android:id="@+id/dots_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center"
        android:layout_alignParentBottom="true" />

</RelativeLayout>

2. 創建一個PagerAdapter類來管理ImageView的顯示：

public class ImagePagerAdapter extends PagerAdapter {

    private Context mContext;
    private int[] mImages;

    public ImagePagerAdapter(Context context, int[] images) {
        mContext = context;
        mImages = images;
    }

    @Override
    public int getCount() {
        return mImages.length;
    }

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        ImageView imageView = new ImageView(mContext);
        imageView.setImageResource(mImages[position]);
        container.addView(imageView);
        return imageView;
    }

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

3. 在Activity中設置ViewPager和指示器：

public class MainActivity extends AppCompatActivity {

    private ViewPager mViewPager;
    private LinearLayout mDotsLayout;

    private int[] mImages = {R.drawable.image1, R.drawable.image2, R.drawable.image3};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mViewPager = findViewById(R.id.view_pager);
        mDotsLayout = findViewById(R.id.dots_layout);

        ImagePagerAdapter adapter = new ImagePagerAdapter(this, mImages);
        mViewPager.setAdapter(adapter);

        addDotsIndicator(0);
        mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}

            @Override
            public void onPageSelected(int position) {
                addDotsIndicator(position);
            }

            @Override
            public void onPageScrollStateChanged(int state) {}
        });
    }

    private void addDotsIndicator(int position) {
        ImageView[] dots = new ImageView[mImages.length];
        mDotsLayout.removeAllViews();
        for (int i = 0; i < dots.length; i++) {
            dots[i] = new ImageView(this);
            dots[i].setImageDrawable(ContextCompat.getDrawable(this, (i == position) ? R.drawable.active_dot : R.drawable.inactive_dot));

            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            params.setMargins(8, 0, 8, 0);
            mDotsLayout.addView(dots[i], params);
        }
    }
}

這樣就實現了ImageView的圖片輪播功能，并且添加了指示器來顯示當前圖片的位置。您可以根據需求自定義指示器的樣式和動畫效果。