RecyclerView实现仿支付宝充值界面

参考博客：https://www.jianshu.com/p/b4bb52cdbeb7
非常感谢上面这位博主的博客给了我非常好的灵感！！！
下面我就先贴一下效果图：

布局代码：

activity代码：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private int[] ints = new int[]{1, 5, 10, 20, 50, 100};
    private ItemAdapter itemAdapter;
    private EditText edt_phone;
    private RecyclerView rv_recharge;
    private Button btn_recharge;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        GridLayoutManager layoutManager = new GridLayoutManager(this, 3);
        rv_recharge.setLayoutManager(layoutManager);
        itemAdapter = new ItemAdapter(ints);
        rv_recharge.setAdapter(itemAdapter);
    }

    private void initView() {
        edt_phone = (EditText) findViewById(R.id.edt_phone);
        rv_recharge = (RecyclerView) findViewById(R.id.rv_recharge);
        btn_recharge = (Button) findViewById(R.id.btn_recharge);
        btn_recharge.setOnClickListener(this);
    }

    private void submit() {
        // validate
        String phone = edt_phone.getText().toString().trim();
        if (TextUtils.isEmpty(phone)) {
            Toast.makeText(this, "充值号码不能为空", Toast.LENGTH_SHORT).show();
            return;
        }

        // TODO validate success, do something
        int index = itemAdapter.getPositionIndex();
        String money = ints[index] + "元";
        Toast.makeText(this, "充值账户：" + phone + " 充值金额：" + money, Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_recharge:
                submit();
                break;
        }
    }
}

adapter代码：

public class ItemAdapter extends RecyclerView.Adapter {
    private int[] ints;
    private int positionIndex = -1;

    public ItemAdapter(int[] ints) {
        this.ints = ints;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
        final ViewHolder holder = new ViewHolder(view);
        holder.tv_item.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int position = holder.getAdapterPosition();
                positionIndex = position;
                Toast.makeText(view.getContext(), ints[position] + "元", Toast.LENGTH_SHORT).show();
                notifyDataSetChanged();
            }
        });
        return holder;
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.tv_item.setText(ints[position] + "元");
        if (position == positionIndex) {//选中
            holder.tv_item.setTextColor(Color.WHITE);
            holder.tv_item.setBackgroundColor(Color.DKGRAY);
        } else {//未选中
            holder.tv_item.setTextColor(Color.BLACK);
            holder.tv_item.setBackgroundColor(Color.WHITE);
        }
    }

    @Override
    public int getItemCount() {
        return ints.length;
    }

    static class ViewHolder extends RecyclerView.ViewHolder {
        View view;
        TextView tv_item;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            this.view = itemView;
            tv_item = (TextView) view.findViewById(R.id.tv_item);
        }
    }

    //返回选中的id
    public int getPositionIndex() {
        return positionIndex;
    }
}

代码做的比较简洁，如有不合理的地方。欢迎指正，请多多指教
下面放了demo地址，因为考虑到有时候会有一些网路问题。所以就放了一个码云地址

GitHub demo地址：https://github.com/shI-215/RechargeApplication.git
码云demo地址：https://gitee.com/oji/RechargeApplication.git