BaseAdapter + ViewHolder不工作

嗨我有一個viewholder +基地適配器，但它不是工作BaseAdapter + ViewHolder不工作

public View getView(int position, View convertView, ViewGroup parent) { 
    View v = convertView; 
    ViewHolder holder; 
    // get the selected entry 
    AI entry = (AI) mListAppInfo.get(position); 

    // inflate new layout if null 
    if(v == null) {   
     holder = new ViewHolder(); 
     v = inflater.inflate(R.layout.list, null); 

     holder.position = position; 
     holder.title = (TextView)v.findViewById(R.id.tvName); 
     holder.icon = (ImageView)v.findViewById(R.id.ivIcon); 
     holder.iconimg = entry.icon; 

     new ThumbnailTask(position, holder) 
     .executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, null); 

     v.setTag(holder); 
    }else{ 
     holder = (ViewHolder) v.getTag(); 
    } 

    holder.title.setText(entry.title); 

    // return view 
    return v; 
}

中列表中的項目不顯示任何東西我究竟做錯了什麼？

編輯這裏是全班

public class AIAdapter extends BaseAdapter { 
    private Context mContext; 
    private List<?> mListAppInfo; 
    private LayoutInflater inflater; 

    public AIAdapter(Context c, List<?> list, PackageManager pm) { 
     mContext = c; 
     mListAppInfo = list; 
     inflater = LayoutInflater.from(mContext); 
    } 

    @Override 
    public int getCount() { 
     return mListAppInfo.size(); 
    } 

    @Override 
    public Object getItem(int position) { 
     return mListAppInfo.get(position); 
    } 

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

    @SuppressWarnings("null") 
    @Override 
    public View getView(int position, View v, ViewGroup parent) { 
     ViewHolder holder; 
     // get the selected entry 
     AI entry = (AI) mListAppInfo.get(position); 

     // inflate new layout if null 
     if(v == null) {   
      holder = new ViewHolder(); 
      v = inflater.inflate(R.layout.list, null); 

      holder.position = position; 
      holder.title = (TextView)v.findViewById(R.id.tvName); 
      holder.icon = (ImageView)v.findViewById(R.id.ivIcon); 
      holder.iconimg = entry.icon; 

      new ThumbnailTask(position, holder) 
      .executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, null); 

      v.setTag(holder); 
     }else{ 
      holder = (ViewHolder) v.getTag(); 
     } 

     holder.title.setText(entry.title); 

     // return view 
     return v; 
    } 

    @SuppressWarnings("rawtypes") 
    private static class ThumbnailTask extends AsyncTask{ 
     private int mPosition; 
     private ViewHolder mHolder; 
     private Rect mOldBounds = new Rect(); 

     public ThumbnailTask(int position, ViewHolder holder) { 
      mPosition = position; 
      mHolder = holder; 
     } 

     @Override 
     protected Drawable doInBackground(Object... arg0) { 
      Drawable icon = mHolder.iconimg; 

      int width = 64; 
      int height = 64; 

      final int iconWidth = icon.getIntrinsicWidth(); 
      final int iconHeight = icon.getIntrinsicHeight(); 

      if (icon instanceof PaintDrawable) { 
       PaintDrawable painter = (PaintDrawable) icon; 
       painter.setIntrinsicWidth(width); 
       painter.setIntrinsicHeight(height); 
      } 

      if (width > 0 && height > 0 && (width < iconWidth || height < iconHeight)) { 
       final float ratio = (float) iconWidth/iconHeight; 

       if (iconWidth > iconHeight) { 
        height = (int) (width/ratio); 
       } else if (iconHeight > iconWidth) { 
        width = (int) (height * ratio); 
       } 

       final Bitmap.Config c = 
         icon.getOpacity() != PixelFormat.OPAQUE ? 
          Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565; 
       final Bitmap thumb = Bitmap.createBitmap(width, height, c); 
       final Canvas canvas = new Canvas(thumb); 
       canvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG, 0)); 
       mOldBounds.set(icon.getBounds()); 
       icon.setBounds(0, 0, width, height); 
       icon.draw(canvas); 
       icon.setBounds(mOldBounds); 
       icon = new BitmapDrawable(thumb); 
      } 

      return icon; 
     } 

     protected void onPostExecute(Drawable bitmap) { 
      if (mHolder.position == mPosition) { 
       mHolder.icon.setImageDrawable(bitmap); 
      } 
     } 

    } 
} 

class ViewHolder{ 
    public int position; 
    public TextView title; 
    public ImageView icon; 
    public Drawable iconimg; 
}

我不知道我做錯了。所有的entry.title和entry.icon都有數據。雖然沒有顯示在列表中。佈局列表中有一個imageview和textview。這工作沒有視圖的，但是一旦我添加視圖它不是

來源

2012-12-11 arberb

檢查幾件事1.你的數據源中有項目2.它進入你的getView（）3.嘗試設置你的文本視圖的顏色 –

「entry.title」是否返回任何內容？你的調試器顯示你什麼？ – Sam

此外，不相關，但如果每一行有不同的圖標，那麼你的縮略圖任務應該超出你的if-else塊 –

一方面沒有必要創建「v」對象，你可以直接使用convertView。你有沒有正確覆蓋你的BaseAdapter類？例如getCount（）方法......它是否返回mListAppInfo.size（）？

乍一看你的方法應該工作;你能複製/粘貼你的整個班級嗎？

來源

2012-12-11 18:36:41

我添加了類 – arberb

當應用viewHolder模式時，您的ViewHolder類需要是靜態的;

現在有點偏離主題，你應該小心那些你發佈了很多的異步任務，你可能要考慮使用線程池。同樣，嘗試考慮SparseArray或HashMap而不是您的適配器中的項目列表，它們在檢索給定索引處的項目然後在列表中更快。

試着在這一行設置一個剎車點：「holder.title.setText（entry.title）;」它到達那裏了嗎？所有的信息是否正確？

來源

2012-12-11 19:29:39

BaseAdapter + ViewHolder不工作

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