简单实现popup网图放大预览

public class PopShowManyBigImage extends BasePopupWindow {

    private TextView tvNUm;
    private MyViewPager viewPager;
    private List<PhotoView> mViews = new ArrayList<>();

    public PopShowManyBigImage(Context context, List<String> imgUrl, int showIndex) {
        super(context);
        if (showIndex < 0 || showIndex >= imgUrl.size()) {
            throw new ArrayIndexOutOfBoundsException();
        }
        for (String url : imgUrl) {
            PhotoView photoView = new PhotoView(context);
            LinearLayout.LayoutParams layoutParams = new
                    LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
            photoView.setLayoutParams(layoutParams);
            mViews.add(photoView);
        }
        viewPager.setAdapter(new ImagePageAdapter(context, imgUrl, mViews));
        //设置初始显示Index（需要在setAdapter之后）
        viewPager.setCurrentItem(showIndex);
        tvNUm.setText(showIndex + 1 + "/" + imgUrl.size());
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                Log.e("viewPager", "onPageSelected:position: " + position);
                tvNUm.setText(position + 1 + "/" + imgUrl.size());
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

    @Override
    public View onCreateContentView() {
        View view = createPopupById(R.layout.pop_show_many_img);
        tvNUm = view.findViewById(R.id.tv_num);
        viewPager = view.findViewById(R.id.view_page);
        return view;
    }
}

pop布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rl_parent"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#00000000">

    <com.qdzr.westcoast.view.MyViewPager
        android:id="@+id/view_page"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/tv_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="50dp"
        android:text=""
        android:textColor="@color/white"
        android:textSize="16sp" />
</RelativeLayout>

pagerAdapter

public class ImagePageAdapter extends PagerAdapter {
    private List<String> mUrlList;
    private List<PhotoView> mViews;
    private Context context;

    public ImagePageAdapter(Context context, List<String> mUrlList, List<PhotoView> mViews) {
        this.context = context;
        this.mUrlList = mUrlList;
        this.mViews = mViews;
    }

    @Override
    public int getCount() {
        return mUrlList == null ? 0 : mUrlList.size();
    }

    @NonNull
    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {
        PhotoView photoView = mViews.get(position);
        GlideUtils.showImage(context, mUrlList.get(position), photoView);
        container.addView(photoView);
        return mViews.get(position);
    }

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

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

相关依赖：
BasePopupWindow
implementation ‘com.github.razerdp:BasePopup:2.2.20’
implementation ‘com.github.razerdp:BasePopup-compat-androidx:2.2.1’
PhotoView
implementation ‘com.github.chrisbanes:PhotoView:2.3.0’
glide
implementation ‘com.github.bumptech.glide:glide:4.12.0’
annotationProcessor ‘com.github.bumptech.glide:compiler:4.12.0’