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我正在开发一个应用程序,其中主要任务是显示不同类型的项目列表(完全是4种不同类型的项目)。为此,我已经实现了一个自定义适配器象下面这样:当它加载的项目首次notifyDataSetChanged不适用于自定义适配器和不同类型的行

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); 
    } 
} 

,似乎一切都很好,但是当我要加载更多的数据,并更新listView没有什么变化,它只显示第一次加载的数据。

为了更新列表中我用下面的代码:

mAdapter.updateNjoftimeList(njoftime); 

这就要求在适配器内部的方法。例如,对于每种不同类型的项目,我都开发了一段代码来显示下面的数据;例如,

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; 

     } 
    } 
} 

我也试试:mAdapter.notifyDataSetChanged()但它没有奏效。

我知道这个问题看起来很像以前问过的很多问题,但我还没有找到解决方案。其中一个原因可能是我必须展示的不同类型的物品。

任何解决方案将不胜感激。

+0

它对我不清楚updateNjoftimeList()导致适配器成员“行”被更新? – CSmith

+0

以及我是基于这个问题:(http://stackoverflow.com/questions/15422120/notifydatasetchange-not-working-from-custom-adapter) – Xhulio

+2

你在做一个非常混乱的方式,这就是为什么它很难弄清楚什么是错的。你在notifyDataSetChanged()中改变的基本上是'njoftime',然而,你的整个逻辑是基于'rows',这是你自定义适配器的列表,它永远不会从我所能看到的更新。这意味着,即使在将新的“行”添加到“njoftime”之后,您的列表也永远不会知道您有更多项目,因为'rows.size()'保持不变。您需要重新填充“行”集合才能使解决方案发挥作用(我相信您可以弄清楚)。 – kha

回答

1

好吧,不知何故我找到了解决方案。诀窍是我已经建立了基于row的适配器,其类型为NjoftimeItemInterface。当我拨打this.notifyDataSetChanged();时,由于适配器的行数相同,因此我没有更新该行的ArrayList,因此没有任何反应。正确的实现如下:

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(); 

} 
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