Android Listview在开始时重复开始特定项目

Question

的项目，该列表显示三个项目，当我向下滚动时，它会创建第四个和第五个项目，但是第六个和下一个项目未创建。这些视图将信息与前五项混合在一起，重复这些视图直到应用程序崩溃并出现ClassCastException。原因很简单，每个项目都有不同的布局和类型，并且每个项目都有不同的ViewHolder。所以当视图没有被创建时，ViewHolders与前五项相同，并且当列表到达具有不同ViewHolder的列表时，它会崩溃（这很可能发生在第十二项）。我需要发现为什么这些项目正在与第一个混合。

这是适配器的代码，我认为这就够了。

public class PostsListAdapter extends BaseAdapter { 
    private FacebookPost[] posts; 
    private LayoutInflater mInflater; 

    public PostsListAdapter (Context ctx, FacebookPost[] user_posts) { 
     mInflater = (LayoutInflater)ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     posts = user_posts; 
    } 

    @Override 
    public int getCount() { 
     return posts.length; 
    } 

    @Override 
    public Object getItem(int position) { 
     return posts[position]; 
    } 

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

    private abstract static class ViewHolder { 
     TextView fromName; 
     TextView arrow; 
     TextView toName; 
     TextView message; 
     TextView attribution; 

    } 
    private static class VideoViewHolder extends ViewHolder { 
     TextView name; 
     TextView caption; 
     TextView description; 
     ImageView icon; 
    } 
    private static class PhotoViewHolder extends ViewHolder { 
    } 
    private static class LinkViewHolder extends ViewHolder { 
    } 
    private static class StatusViewHolder extends ViewHolder { 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder holder; 
     Log.d("POSITION",""+position); 
     if(convertView == null) { 
      switch(posts[position].getType()) { 
       case FacebookPost.VIDEO: 
        Log.d(""+position,"VIDEO"); 
        convertView = mInflater.inflate(R.layout.post_list_item_video, parent, false); 
        holder = new VideoViewHolder(); 
        holder.fromName = (TextView)convertView.findViewById(R.id.post_list_item_video_from_name); 
        holder.arrow = (TextView)convertView.findViewById(R.id.post_list_item_video_arrow); 
        holder.toName = (TextView)convertView.findViewById(R.id.post_list_item_video_to_name); 
        holder.message = (TextView)convertView.findViewById(R.id.post_list_item_video_message); 
        ((VideoViewHolder)holder).name = (TextView)convertView.findViewById(R.id.post_list_item_video_name); 
        ((VideoViewHolder)holder).caption = (TextView)convertView.findViewById(R.id.post_list_item_video_caption); 
        ((VideoViewHolder)holder).description = (TextView)convertView.findViewById(R.id.post_list_item_video_description); 
        break; 
       case FacebookPost.LINK: 
        Log.d(""+position,"LINK"); 
        convertView = mInflater.inflate(R.layout.post_list_item_link, parent, false); 
        holder = new LinkViewHolder(); 
        holder.fromName = (TextView)convertView.findViewById(R.id.post_list_item_link_from_name); 
        holder.arrow = (TextView)convertView.findViewById(R.id.post_list_item_link_arrow); 
        holder.toName = (TextView)convertView.findViewById(R.id.post_list_item_link_to_name); 
        holder.message = (TextView)convertView.findViewById(R.id.post_list_item_link_message); 
        break; 
       case FacebookPost.STATUS: 
        Log.d(""+position,"STATUS"); 
        convertView = mInflater.inflate(R.layout.post_list_item_status, parent, false); 
        holder = new StatusViewHolder(); 
        holder.fromName = (TextView)convertView.findViewById(R.id.post_list_item_status_from_name); 
        holder.arrow = (TextView)convertView.findViewById(R.id.post_list_item_status_arrow); 
        holder.toName = (TextView)convertView.findViewById(R.id.post_list_item_status_to_name); 
        holder.message = (TextView)convertView.findViewById(R.id.post_list_item_status_message); 
        break; 
       case FacebookPost.PHOTO: 
        Log.d(""+position,"PHOTO"); 
        convertView = mInflater.inflate(R.layout.post_list_item_photo, parent, false); 
        holder = new PhotoViewHolder(); 
        holder.fromName = (TextView)convertView.findViewById(R.id.post_list_item_photo_from_name); 
        holder.arrow = (TextView)convertView.findViewById(R.id.post_list_item_photo_arrow); 
        holder.toName = (TextView)convertView.findViewById(R.id.post_list_item_photo_to_name); 
        holder.message = (TextView)convertView.findViewById(R.id.post_list_item_photo_message); 
        break; 
       default: 
        holder=null; 
        break; 
      } 
      convertView.setTag(holder); 
     } 
     else { 
      holder = (ViewHolder)convertView.getTag(); 
     } 

     Spanned text = Html.fromHtml(posts[position].getFrom().getName()); 
     holder.fromName.setText(text); 

     if(posts[position].getTo() != null) 
      text = Html.fromHtml(posts[position].getTo()[0].getName()); 
     else 
      text=null; 
     if(text==null) { 
      holder.arrow.setVisibility(View.GONE); 
      holder.toName.setVisibility(View.GONE); 
     } else 
      holder.toName.setText(text); 

     text = Html.fromHtml(posts[position].getMessage()); 
     holder.message.setText(text); 

     switch(posts[position].getType()) { 
      case FacebookPost.VIDEO: 
       text = Html.fromHtml(((FacebookVideoPost)posts[position]).getCaption()); 
       Log.d("CAST: "+position,holder.getClass().getName()); 
       ((VideoViewHolder)holder).caption.setText(text); 
       text = Html.fromHtml(((FacebookVideoPost)posts[position]).getName()); 
       ((VideoViewHolder)holder).name.setText(text); 
       text = Html.fromHtml(((FacebookVideoPost)posts[position]).getDescription()); 
       ((VideoViewHolder)holder).description.setText(text); 
       break; 
      case FacebookPost.LINK: 
       break; 
      case FacebookPost.STATUS: 
       Log.d("CAST: "+position,holder.getClass().getName()); 
       break; 
      case FacebookPost.PHOTO: 
       break; 
     } 

     return convertView; 
    } 
} 

谢谢你的一切。

Answer 1

我猜你缺少getViewTypeCount