notifyDataSetChanged不適用於自定義適配器和不同類型的行

Question

我正在開發一個應用程序，其中的主要任務是顯示不同類型的項目的列表（恰好是4種不同類型的項目）。 為此，我實現了一個自定義適配器，如下所示：

public class NjoftimeAdapter extends BaseAdapter {


    final List<NjoftimeItemInterface> rows;
    final ArrayList<Njoftime> njoftime;


    NjoftimeAdapter(ArrayList<Njoftime> njoftime, Context context) {

        this.njoftime = njoftime;
        rows = new ArrayList<NjoftimeItemInterface>();// member variable
        // iteron mbi objektet e bizneset dhe kontrollon cfare tipi eshte. Ne
        // varesi te tipit theret adapterin e tij
        for (Njoftime njoftim : njoftime) {

            if (njoftim.getType() == NjoftimeKategori.PUNA_IME.ordinal()) {
                rows.add(new PunaImeAdapter(LayoutInflater.from(context),
                        njoftim, context));
            }
            if (njoftim.getType() == NjoftimeKategori.NJOFTIME_CATEGORY.ordinal()) {
                rows.add(new OthersAdapter(LayoutInflater.from(context),
                        njoftim, context));
            }

            if (njoftim.getType() == NjoftimeKategori.MAKINA_CATEGORY.ordinal()) {
                rows.add(new MakinaAdapter(LayoutInflater.from(context),
                        njoftim, context));
            }

            if (njoftim.getType() == NjoftimeKategori.PRONA_CATEGORY.ordinal()) {
                rows.add(new PronaAdapter(LayoutInflater.from(context),
                        njoftim, context));
            }

        }
    }

    @Override
    public int getViewTypeCount() {
        return NjoftimeKategori.values().length;
    }

    @Override
    public int getItemViewType(int position) {
        return rows.get(position).getViewType();
    }

    public int getCount() {
        return rows.size();
    }

    public void updateNjoftimeList(ArrayList<Njoftime> newList){

        njoftime.clear();
        njoftime.addAll(newList);
        this.notifyDataSetChanged();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        return rows.get(position).getView(convertView);
    }
}

當它第一次加載項目時，一切似乎都很好，但是當我想加載更多數據並更新listView沒有任何變化，它只顯示第一次加載的數據。

為了更新列表，我使用了以下代碼：

 mAdapter.updateNjoftimeList(njoftime);

在適配器內部調用該方法。

例如，對於每種不同類型的項目，我開發了一段代碼來顯示數據，如下所示；

OtherAdapter:

public class OthersAdapter implements NjoftimeItemInterface {

    private Njoftime njoftime;
    private LayoutInflater inflater;
    private Context mContext;

    public OthersAdapter(LayoutInflater inflater, Njoftime njoftime, Context context) {
        this.njoftime = njoftime;
        this.inflater = inflater;
        this.mContext = context;
    }

    public View getView(View convertView) {
        ViewHolder holder;
        View view;
        //we have a don't have a converView so we'll have to create a new one
        if (convertView == null) {
            ViewGroup viewGroup = (ViewGroup) inflater.inflate(R.layout.other_element, null);

            //use the view holder pattern to save of already looked up subviews
            holder = new ViewHolder(
                    (TextView) viewGroup.findViewById(R.id.tittle),
                    (TextView) viewGroup.findViewById(R.id.short_desc),
                    (TextView) viewGroup.findViewById(R.id.category),
                    (RelativeLayout)viewGroup.findViewById(R.id.card));
            viewGroup.setTag(holder);

            view = viewGroup;
        } else {
            //get the holder back out
            holder = (ViewHolder) convertView.getTag();

            view = convertView;
        }

        //change the font
        Typeface typeFace = Typeface.createFromAsset(mContext.getAssets(), "fonts/Lato-Regular.ttf");

        holder.category.setTypeface(typeFace);
        holder.short_description.setTypeface(typeFace);
        holder.title.setTypeface(typeFace);

        Others other = (Others) njoftime;

        holder.title.setText(other.getTitle());
        holder.short_description.setText(other.getShort_desc());
        holder.category.setText(other.getCategory());

        if(other.getSponsor()){
            holder.card.setBackgroundResource(R.drawable.njoftime_item_background_sponsor);
        }

        return view;
    }


    public int getViewType() {
        return NjoftimeKategori.NJOFTIME_CATEGORY.ordinal();
    }

    public class ViewHolder {

        public TextView title;
        public TextView short_description;
        public TextView category;
        public RelativeLayout card;


        public ViewHolder(TextView title, TextView short_description, TextView category,RelativeLayout card) {

            this.title = title;
            this.short_description = short_description;
            this.category = category;
            this.card = card;

        }
    }
}

我也嘗試過： mAdapter.notifyDataSetChanged()但也沒有用。

我知道這個問題似乎像以前問過的很多問題一樣，但是我還沒有找到解決方案。 原因之一可能是我必須顯示的項目類型不同。

任何解決方案將不勝感激。

Answer 1

好吧，我以某種方式找到了解決方案。 訣竅是我已經基於NjoftimeItemInterface類型的row構建了適配器。 當我調用this.notifyDataSetChanged(); 因為適配器沒有相同的行數，所以沒有任何反應，因為我沒有更新該行的ArrayList。 正確的實現如下：

public void updateNjoftimeList(ArrayList<Njoftime> newList){


    for (Njoftime njoftim : newList) {

        if (njoftim.getType() == NjoftimeKategori.PUNA_IME.ordinal()) {
            rows.add(new PunaImeAdapter(LayoutInflater.from(mContext),
                    njoftim, mContext));
        }
        if (njoftim.getType() == NjoftimeKategori.NJOFTIME_CATEGORY.ordinal()) {
            rows.add(new OthersAdapter(LayoutInflater.from(mContext),
                    njoftim, mContext));
        }

        if (njoftim.getType() == NjoftimeKategori.MAKINA_CATEGORY.ordinal()) {
            rows.add(new MakinaAdapter(LayoutInflater.from(mContext),
                    njoftim, mContext));
        }

        if (njoftim.getType() == NjoftimeKategori.PRONA_CATEGORY.ordinal()) {
            rows.add(new PronaAdapter(LayoutInflater.from(mContext),
                    njoftim, mContext));
        }
    }

    this.notifyDataSetChanged();

}