Android viewpager2 3D画廊

1.添加依赖：

在你的build.gradle文件中添加ViewPager2的依赖：

   implementation 'androidx.viewpager2:viewpager2:1.0.0'
   

2.布局文件：

在你的布局文件中添加ViewPager2组件：

   <androidx.viewpager2.widget.ViewPager2
       android:id="@+id/viewPager2"
       android:layout_width="match_parent"
       android:layout_height="match_parent" />
   

3.创建适配器：

创建一个继承自RecyclerView.Adapter的适配器来管理ViewPager2中的页面：

   public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.GalleryViewHolder> {
       private List<Bitmap> images;

       public GalleryAdapter(List<Bitmap> images) {
           this.images = images;
       }

       @NonNull
       @Override
       public GalleryViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
           View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_gallery, parent, false);
           return new GalleryViewHolder(itemView);
       }

       @Override
       public void onBindViewHolder(@NonNull GalleryViewHolder holder, int position) {
           holder.imageView.setImageBitmap(images.get(position));
       }

       @Override
       public int getItemCount() {
           return images.size();
       }

       static class GalleryViewHolder extends RecyclerView.ViewHolder {
           ImageView imageView;

           GalleryViewHolder(View itemView) {
               super(itemView);
               imageView = itemView.findViewById(R.id.imageView);
           }
       }
   }
   

4.设置3D转换效果：

为ViewPager2设置一个PageTransformer来实现3D效果：

   viewPager2.setPageTransformer(new ViewPager2.PageTransformer() {
       @Override
       public void transformPage(@NonNull View page, float position) {
           final float MIN_SCALE = 0.75f;
           final float MIN_ALPHA = 0.5f;

           if (position < -1) { // [-Infinity,-1)
               // Page is completely off-screen to the left.
               page.setAlpha(0);
           } else if (position <= 1) { // [-1,1]
               // Modify the default slide transition to shrink the page as well
               float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
               float vertMargin = page.getHeight() * (1 - scaleFactor) / 2;
               float horzMargin = page.getWidth() * (1 - scaleFactor) / 2;
               if (position < 0) {
                   page.setTranslationX(horzMargin - vertMargin / 2);
               } else {
                   page.setTranslationX(-horzMargin + vertMargin / 2);
               }

               // Scale the page down (between MIN_SCALE and 1)
               page.setScaleX(scaleFactor);
               page.setScaleY(scaleFactor);

               // Fade the page relative to its size.
               page.setAlpha(MIN_ALPHA +
                       (scaleFactor - MIN_SCALE) /
                               (1 - MIN_SCALE) * (1 - MIN_ALPHA));
           } else { // (1,+Infinity]
               // Page is completely off-screen to the right.
               page.setAlpha(0);
           }
       }
   });
   

5.初始化ViewPager2：

在Activity或Fragment中初始化ViewPager2并设置适配器：

   List<Bitmap> images = ...; // 初始化你的图片列表
   GalleryAdapter adapter = new GalleryAdapter(images);
   viewPager2.setAdapter(adapter);