问ArrayList在回收视图中的动态显示数据
EN

Stack Overflow用户

提问于 2018-06-22 01:20:04

回答 1查看 0关注 0票数 0

我希望显示存储在列表中的特定数据。RecyclerView。我正在解析一个JSON数组并将其存储在一个列表中。JSON数组中有15个单独的元素，我正在解析这些元素，并将其存储在列表中。这15个元素就像一组。该数组可能包含超过10组作为服务器响应的集合。现在，如果我想得到一些特定的元素，假设第5个元素，如果我调用list.get(4)它显示了第四组的所有15个元素。现在，我只想在其中显示特定的数据。RecyclerView动态地。直到数据结束，回收者的视图应该填充和显示数据。我如何实现？

public List parseJson(){
    String finalJson = BuffClass.mainbuff.toString(); // mainbuff contains json array
    ArrayList<HashMap<String, String>> modellist= new ArrayList<>();

    JSONObject parentObject = new JSONObject(finalJson);
    JSONArray parentArray = parentObject.getJSONArray("results");

    Gson gson = new Gson();
    for(int i=0; i<parentArray.length(); i++) {
        JSONObject finalObject = parentArray.getJSONObject(i);

        //parent
        String parentid=finalObject.getString("id");  
        String parenteventid=finalObject.getString("event_id");
        String parenttime=finalObject.getString("time");

        JSONObject homeModel = finalObject.getJSONObject("hometown");

        //child element inside JSON array which contains data
        String homeid=homeModel.getString("id");
        String homename=homeModel.getString("name");
        String homeimage_id=homeModel.getString("image_id");

        JSONObject homeModel = finalObject.getJSONObject("city");   

        // Child element inside JSON array which contains data
        String cityid=cityModel.getString("id");
        String cityname=cityModel.getString("name");
        String cityimage_id=cityModel.getString("image_id");

        HashMap<String, String> finalval = new HashMap<>();
        finalval.put("Parent id", parentid);
        finalval.put("Parent sportid", parentsportid);
        finalval.put("Parent time", parenttime);

        finalval.put("Home name",homename);
        finalval.put("Home id",homeid);
        finalval.put("Home imageid",homeimage_id);

        finalval.put("city Model name",cityname);
        finalval.put("Away Model id",cityid);
        finalval.put("Away Model imageid",cityimage_id);

        modellist.add(finalval);  // adding all hashmap data to list.
}

return modellist;

现在我想在RecyclerView循环直到数据结束。

回答 1

Stack Overflow用户

发布于 2018-06-22 10:50:43

RecyclerView。关键的思想是为不同的数据集拥有不同的视图类型。获取数据的类型。onCreateViewHolder并返回特定数据的确切视图持有人。可以考虑有一个额外的字段来跟踪哪个集是父母，哪个是家，哪个是城市。可以在RecyclerView基于从onCreateViewHolder。

为了方便，我共享适配器。

private class DynamicListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private static final int FOOTER_VIEW = 1;
    private static final int FIRST_LIST_ITEM_VIEW = 2;
    private static final int FIRST_LIST_HEADER_VIEW = 3;
    private static final int SECOND_LIST_ITEM_VIEW = 4;
    private static final int SECOND_LIST_HEADER_VIEW = 5;

    public DynamicListAdapter() {
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        // List items of first list
        private TextView mTextDescription1;
        private TextView mListItemTitle1;

        // List items of second list
        private TextView mTextDescription2;
        private TextView mListItemTitle2;

        // Element of footer view
        private TextView footerTextView;

        public ViewHolder(final View itemView) {
            super(itemView);

            // Get the view of the elements of first list
            mTextDescription1 = (TextView) itemView.findViewById(R.id.description1);
            mListItemTitle1 = (TextView) itemView.findViewById(R.id.title1);

            // Get the view of the elements of second list
            mTextDescription2 = (TextView) itemView.findViewById(R.id.description2);
            mListItemTitle2 = (TextView) itemView.findViewById(R.id.title2);

            // Get the view of the footer elements
            footerTextView = (TextView) itemView.findViewById(R.id.footer);
        }

        public void bindViewSecondList(int pos) {

            if (firstList == null) pos = pos - 1;
            else {
                if (firstList.size() == 0) pos = pos - 1;
                else pos = pos - firstList.size() - 2;
            }

            final String description = secondList.get(pos).getDescription();
            final String title = secondList.get(pos).getTitle();

            mTextDescription2.setText(description);
            mListItemTitle2.setText(title);
        }

        public void bindViewFirstList(int pos) {

            // Decrease pos by 1 as there is a header view now.
            pos = pos - 1;

            final String description = firstList.get(pos).getDescription();
            final String title = firstList.get(pos).getTitle();

            mTextDescription1.setText(description);
            mListItemTitle1.setText(title);
        }

        public void bindViewFooter(int pos) {
            footerTextView.setText("This is footer");
        }
    }

    public class FooterViewHolder extends ViewHolder {
        public FooterViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class FirstListHeaderViewHolder extends ViewHolder {
        public FirstListHeaderViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class FirstListItemViewHolder extends ViewHolder {
        public FirstListItemViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class SecondListHeaderViewHolder extends ViewHolder {
        public SecondListHeaderViewHolder(View itemView) {
            super(itemView);
        }
    }

    private class SecondListItemViewHolder extends ViewHolder {
        public SecondListItemViewHolder(View itemView) {
            super(itemView);
        }
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View v;

        if (viewType == FOOTER_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_footer, parent, false);
            FooterViewHolder vh = new FooterViewHolder(v);
            return vh;

        } else if (viewType == FIRST_LIST_ITEM_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_first_list, parent, false);
            FirstListItemViewHolder vh = new FirstListItemViewHolder(v);
            return vh;

        } else if (viewType == FIRST_LIST_HEADER_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_first_list_header, parent, false);
            FirstListHeaderViewHolder vh = new FirstListHeaderViewHolder(v);
            return vh;

        } else if (viewType == SECOND_LIST_HEADER_VIEW) {
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_second_list_header, parent, false);
            SecondListHeaderViewHolder vh = new SecondListHeaderViewHolder(v);
            return vh;

        } else {
            // SECOND_LIST_ITEM_VIEW
            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_second_list, parent, false);
            SecondListItemViewHolder vh = new SecondListItemViewHolder(v);
            return vh;
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

        try {
            if (holder instanceof SecondListItemViewHolder) {
                SecondListItemViewHolder vh = (SecondListItemViewHolder) holder;
                vh.bindViewSecondList(position);

            } else if (holder instanceof FirstListHeaderViewHolder) {
                FirstListHeaderViewHolder vh = (FirstListHeaderViewHolder) holder;

            } else if (holder instanceof FirstListItemViewHolder) {
                FirstListItemViewHolder vh = (FirstListItemViewHolder) holder;
                vh.bindViewFirstList(position);

            } else if (holder instanceof SecondListHeaderViewHolder) {
                SecondListHeaderViewHolder vh = (SecondListHeaderViewHolder) holder;

            } else if (holder instanceof FooterViewHolder) {
                FooterViewHolder vh = (FooterViewHolder) holder;
                vh.bindViewFooter(position);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public int getItemCount() {

        int firstListSize = 0;
        int secondListSize = 0;

        if (secondList == null && firstList == null) return 0;

        if (secondList != null)
            secondListSize = secondList.size();
        if (firstList != null)
            firstListSize = firstList.size();

        if (secondListSize > 0 && firstListSize > 0)
            return 1 + firstListSize + 1 + secondListSize + 1;   // first list header, first list size, second list header , second list size, footer
        else if (secondListSize > 0 && firstListSize == 0)
            return 1 + secondListSize + 1;                       // second list header, second list size, footer
        else if (secondListSize == 0 && firstListSize > 0)
            return 1 + firstListSize;                            // first list header , first list size
        else return 0;
    }

    @Override
    public int getItemViewType(int position) {

        int firstListSize = 0;
        int secondListSize = 0;

        if (secondList == null && firstList == null)
            return super.getItemViewType(position);

        if (secondList != null)
            secondListSize = secondList.size();
        if (firstList != null)
            firstListSize = firstList.size();

        if (secondListSize > 0 && firstListSize > 0) {
            if (position == 0) return FIRST_LIST_HEADER_VIEW;
            else if (position == firstListSize + 1)
                return SECOND_LIST_HEADER_VIEW;
            else if (position == secondListSize + 1 + firstListSize + 1)
                return FOOTER_VIEW;
            else if (position > firstListSize + 1)
                return SECOND_LIST_ITEM_VIEW;
            else return FIRST_LIST_ITEM_VIEW;

        } else if (secondListSize > 0 && firstListSize == 0) {
            if (position == 0) return SECOND_LIST_HEADER_VIEW;
            else if (position == secondListSize + 1) return FOOTER_VIEW;
            else return SECOND_LIST_ITEM_VIEW;

        } else if (secondListSize == 0 && firstListSize > 0) {
            if (position == 0) return FIRST_LIST_HEADER_VIEW;
            else return FIRST_LIST_ITEM_VIEW;
        }

        return super.getItemViewType(position);
    }
}

请注意，我有五个不同的观点，并根据它们在ArrayList，我将从名为getItemViewType。

票数 0

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/-100005494

复制

相似问题

问ArrayList在回收视图中的动态显示数据
EN

回答 1

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问ArrayList在回收视图中的动态显示数据EN

回答 1

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问ArrayList在回收视图中的动态显示数据
EN