android画廊效果怎么实现

要实现类似于Android画廊效果，可以使用RecyclerView和ViewPager组合来实现。

1. 首先，创建一个包含RecyclerView和ViewPager的布局文件。

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

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="200dp"/>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

2. 创建一个自定义的RecyclerView.Adapter来填充RecyclerView的数据。

public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.ViewHolder> {
    private List<Drawable> images;

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

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

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.image.setImageDrawable(images.get(position));
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        ImageView image;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            image = itemView.findViewById(R.id.imageView);
        }
    }
}

3. 创建一个自定义的ViewPager.Adapter来填充ViewPager的数据。

public class ViewPagerAdapter extends PagerAdapter {
    private List<Drawable> images;

    public ViewPagerAdapter(List<Drawable> images) {
        this.images = images;
    }

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

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

    @NonNull
    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {
        ImageView imageView = new ImageView(container.getContext());
        imageView.setImageDrawable(images.get(position));
        container.addView(imageView);
        return imageView;
    }

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

4. 在Activity中初始化RecyclerView和ViewPager，设置Adapter并填充数据。

public class MainActivity extends AppCompatActivity {
    private RecyclerView recyclerView;
    private ViewPager viewPager;

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

        recyclerView = findViewById(R.id.recyclerView);
        viewPager = findViewById(R.id.viewPager);

        List<Drawable> images = new ArrayList<>();
        images.add(getDrawable(R.drawable.image1));
        images.add(getDrawable(R.drawable.image2));
        images.add(getDrawable(R.drawable.image3));

        GalleryAdapter galleryAdapter = new GalleryAdapter(images);
        recyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
        recyclerView.setAdapter(galleryAdapter);

        ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(images);
        viewPager.setAdapter(viewPagerAdapter);
    }
}

通过以上步骤，即可实现类似于Android画廊效果的功能。RecyclerView用于显示缩略图列表，ViewPager用于显示大图。可以根据需求自定义布局和样式来实现更丰富的效果。