Android实现图片九宫格

public class Img {
    public Integer img1;
    public Integer img2;
    public Integer img3;
    public Integer img4;
    public Integer img5;
    public Integer img6;
    public Integer img7;
    public Integer img8;
    public Integer img9;

    public Img(Integer img1, Integer img2, Integer img3, Integer img4, Integer img5, Integer img6, Integer img7, Integer img8, Integer img9) {
        this.img1 = img1;
        this.img2 = img2;
        this.img3 = img3;
        this.img4 = img4;
        this.img5 = img5;
        this.img6 = img6;
        this.img7 = img7;
        this.img8 = img8;
        this.img9 = img9;
    }

    public int count(){
        int i=0;
        if (img1!=null)i++;
        if (img2!=null)i++;
        if (img3!=null)i++;
        if (img4!=null)i++;
        if (img5!=null)i++;
        if (img6!=null)i++;
        if (img7!=null)i++;
        if (img8!=null)i++;
        if (img9!=null)i++;
        return i;
    }
    public boolean isOne(){
        return count()==1;
    }
    public boolean isTwoOrFour(){
        return count()==2||count()==4;
    }
    public boolean isFour(){
        return count()==4;
    }
    public boolean isOther(){
        if (count()!=1){
            if (count()!=2){
                return count() != 4;
            }
        }
        return false;
    }
}

public class ImgAdapter {
    @BindingAdapter("localImg")
    public static void set(ImageView imageView,Integer res){
        if (res==null){
            imageView.setVisibility(View.GONE);
            return;
        }
        imageView.setImageResource(res);

    }
}

public class MyAdapter extends RecyclerView.Adapter {

    private final Context context;
    public List imgs;

    public MyAdapter(Context context,List imgs) {
        this.context = context;
        this.imgs=imgs;
    }

    @NonNull
    @Override
    public Holder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        ItemImgBinding binding = ItemImgBinding.inflate(
                LayoutInflater.from(context),
                parent,
                false);
        return new Holder(binding);
    }

    @Override
    public void onBindViewHolder(@NonNull Holder holder, int position) {
        Img img = imgs.get(position);
        holder.binding.setImg(img);
        holder.binding.executePendingBindings();
    }

    @Override
    public int getItemViewType(int position) {
        return position;
    }

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

    public class Holder extends RecyclerView.ViewHolder {
        ItemImgBinding binding;
        public Holder(ItemImgBinding binding) {
            super(binding.getRoot());
            this.binding=binding;
        }
    }
}

public class MainActivity extends AppCompatActivity {

    ActivityMainBinding binding;
    MyAdapter myAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        List imgs = Arrays.asList(
                new Img(R.drawable.avatar_1, null, null, null, null, null, null, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, null, null, null, null, null, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, null, null, null, null, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, R.drawable.avatar_4, null, null, null, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, R.drawable.avatar_4, R.drawable.avatar_5, null, null, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, R.drawable.avatar_4, R.drawable.avatar_5, R.drawable.avatar_6, null, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, R.drawable.avatar_4, R.drawable.avatar_5, R.drawable.avatar_6, R.drawable.avatar_7, null, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, R.drawable.avatar_4, R.drawable.avatar_5, R.drawable.avatar_6, R.drawable.avatar_7, R.drawable.avatar_8, null),
                new Img(R.drawable.avatar_1, R.drawable.avatar_2, R.drawable.avatar_3, R.drawable.avatar_4, R.drawable.avatar_5, R.drawable.avatar_6, R.drawable.avatar_7, R.drawable.avatar_8, R.drawable.avatar_9)
        );

        myAdapter=new MyAdapter(this,imgs);
        binding.recyclerView.setLayoutManager(new LinearLayoutManager(this));
        binding.recyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));
        binding.recyclerView.setAdapter(myAdapter);
    }
}