Question

我点了这个链接http://anandbose.github.io/android_recyclerview_expandablelistview.html 了解如何从回收站视图执行可扩展列表视图。

一切都很好，但现在我想点击孩子，它会转到下一页并显示文字。

例如，我点击了Car（标题） - ＆gt;奥迪（儿童） - ＆gt;转到下一页并打印奥迪

我阅读了源代码和最后几句陈述

 The advantage of RecyclerView is that it doesn't have onItemClickListener, so the click events will be directly supplied to the child.

如何为孩子实现onItemClickListener？

Answer 1

基本上你需要传递给Adapter监听器（来自activity / fragment）。我改变了谷歌的基本例子，

请参阅以下代码

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private RecyclerView recyclerview;
    private List<ExpandableListAdapter.Item> data;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        recyclerview = (RecyclerView) findViewById(R.id.recyclerview);
        recyclerview.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
        data = new ArrayList<>();

        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.HEADER, "Fruits"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Apple"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Orange"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Banana"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.HEADER, "Cars"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Audi"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Aston Martin"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "BMW"));
        data.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Cadillac"));

        ExpandableListAdapter.Item places = new ExpandableListAdapter.Item(ExpandableListAdapter.HEADER, "Places");
        places.invisibleChildren = new ArrayList<>();
        places.invisibleChildren.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Kerala"));
        places.invisibleChildren.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Tamil Nadu"));
        places.invisibleChildren.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Karnataka"));
        places.invisibleChildren.add(new ExpandableListAdapter.Item(ExpandableListAdapter.CHILD, "Maharashtra"));

        data.add(places);

        recyclerview.setAdapter(new ExpandableListAdapter(data,this));
    }

    @Override
    public void onClick(View view) {

        int position = (Integer)view.getTag();

        Toast.makeText(view.getContext(), "position=" + position + " clicked on" + data.get(position).text, Toast.LENGTH_SHORT).show();


    }

}

<强>适配器

public class ExpandableListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    public static final int HEADER = 0;
    public static final int CHILD = 1;

    private List<Item> data;
    private View.OnClickListener _listener;

    public ExpandableListAdapter(List<Item> data, View.OnClickListener listener) {
        this.data = data;
        _listener = listener;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int type) {
        View view = null;
        Context context = parent.getContext();
        float dp = context.getResources().getDisplayMetrics().density;
        int subItemPaddingLeft = (int) (18 * dp);
        int subItemPaddingTopAndBottom = (int) (5 * dp);
        switch (type) {
            case HEADER:
                LayoutInflater inflater = (LayoutInflater) parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                view = inflater.inflate(R.layout.list_header, parent, false);
                ListHeaderViewHolder header = new ListHeaderViewHolder(view);
                return header;
            case CHILD:
                TextView itemTextView = new TextView(context);
                itemTextView.setPadding(subItemPaddingLeft, subItemPaddingTopAndBottom, 0, subItemPaddingTopAndBottom);
                itemTextView.setTextColor(0x88000000);
                itemTextView.setLayoutParams(
                        new ViewGroup.LayoutParams(
                                ViewGroup.LayoutParams.MATCH_PARENT,
                                ViewGroup.LayoutParams.WRAP_CONTENT));
                return new RecyclerView.ViewHolder(itemTextView) {
                };
        }
        return null;
    }

    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        final Item item = data.get(position);
        switch (item.type) {
            case HEADER:
                final ListHeaderViewHolder itemController = (ListHeaderViewHolder) holder;
                itemController.refferalItem = item;
                itemController.header_title.setText(item.text);
                if (item.invisibleChildren == null) {
                    itemController.btn_expand_toggle.setImageResource(R.drawable.circle_minus);
                } else {
                    itemController.btn_expand_toggle.setImageResource(R.drawable.circle_plus);
                }
                itemController.btn_expand_toggle.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        if (item.invisibleChildren == null) {
                            item.invisibleChildren = new ArrayList<Item>();
                            int count = 0;
                            int pos = data.indexOf(itemController.refferalItem);
                            while (data.size() > pos + 1 && data.get(pos + 1).type == CHILD) {
                                item.invisibleChildren.add(data.remove(pos + 1));
                                count++;
                            }
                            notifyItemRangeRemoved(pos + 1, count);
                            itemController.btn_expand_toggle.setImageResource(R.drawable.circle_plus);
                        } else {
                            int pos = data.indexOf(itemController.refferalItem);
                            int index = pos + 1;
                            for (Item i : item.invisibleChildren) {
                                data.add(index, i);
                                index++;
                            }
                            notifyItemRangeInserted(pos + 1, index - pos - 1);
                            itemController.btn_expand_toggle.setImageResource(R.drawable.circle_minus);
                            item.invisibleChildren = null;
                        }
                    }
                });
                break;
            case CHILD:
                TextView itemTextView = (TextView) holder.itemView;
                itemTextView.setText(data.get(position).text);
                itemTextView.setTag(position);
                itemTextView.setOnClickListener(_listener);
                break;
        }
    }

    @Override
    public int getItemViewType(int position) {
        return data.get(position).type;
    }

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

    private static class ListHeaderViewHolder extends RecyclerView.ViewHolder {
        public TextView header_title;
        public ImageView btn_expand_toggle;
        public Item refferalItem;

        public ListHeaderViewHolder(View itemView) {
            super(itemView);
            header_title = (TextView) itemView.findViewById(R.id.header_title);
            btn_expand_toggle = (ImageView) itemView.findViewById(R.id.btn_expand_toggle);
        }
    }



    public static class Item {
        public int type;
        public String text;
        public List<Item> invisibleChildren;

        public Item() {
        }

        public Item(int type, String text) {
            this.type = type;
            this.text = text;
        }
    }
}

来自RecyclerView的ExpandableListView获取子位置

1 个答案: