安卓RecyclerView 单选

实现RecyclerView列表单选功能的步骤如下：

1.在RecyclerView的适配器中添加一个变量来保存当前选中的位置，例如selPos。

2.在适配器的onBindViewHolder方法中，根据当前位置是否为selPos来设置单选框的状态。

3.在适配器的构造方法中添加一个接口，用于监听单选框的点击事件。

4.在Activity或Fragment中实现该接口，并在回调方法中更新selPos的值，并调用适配器的notifyDataSetChanged方法刷新列表。

下面是一个简单的示例代码：

public class SingleChoiceAdapter extends RecyclerView.Adapter<SingleChoiceAdapter.ViewHolder> {
    private List<String> mData;
    private int mSelPos = -1;
    private OnItemClickListener mListener;

    public SingleChoiceAdapter(List<String> data, OnItemClickListener listener) {
        mData = data;
        mListener = listener;
    }

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

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        holder.mTextView.setText(mData.get(position));
        holder.mRadioButton.setChecked(position == mSelPos);
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mSelPos = position;
                notifyDataSetChanged();
                mListener.onItemClick(position);
            }
        });
    }

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

    public int getSelPos() {
        return mSelPos;
    }

    public interface OnItemClickListener {
        void onItemClick(int position);
    }

    static class ViewHolder extends RecyclerView.ViewHolder {
        TextView mTextView;
        RadioButton mRadioButton;

        ViewHolder(View itemView) {
            super(itemView);
            mTextView = itemView.findViewById(R.id.text_view);
            mRadioButton = itemView.findViewById(R.id.radio_button);
        }
    }
}

在Activity或Fragment中使用该适配器：

public class MainActivity extends AppCompatActivity implements SingleChoiceAdapter.OnItemClickListener {
    private RecyclerView mRecyclerView;
    private SingleChoiceAdapter mAdapter;

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

        mRecyclerView = findViewById(R.id.recycler_view);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        List<String> data = new ArrayList<>();
        data.add("Item 1");
        data.add("Item 2");
        data.add("Item 3");
        data.add("Item 4");
        data.add("Item 5");

        mAdapter = new SingleChoiceAdapter(data, this);
        mRecyclerView.setAdapter(mAdapter);
    }

    @Override
    public void onItemClick(int position) {
        Toast.makeText(this, "Selected position: " + position, Toast.LENGTH_SHORT).show();
    }
}