recyclerview现在可以很好地向上或向下滚动

Question

我使用的是拥有两个项目，一个ImageView和一个TextView的卡片视图的recyclerview适配器。 但是当我向上或向下滚动时，我收到奇怪的数据。

这里是我的全部代码

public class MyCustomAdapterDishes extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements View.OnClickListener{ 

private Button sendBtn; 
private ChatAdapter adapter; 
    private ArrayList<Dishes> dish; 
    private Context mContext; 
View rowView; 

private static final int TYPE_HEADER = 0; 
private static final int TYPE_ITEM = 1; 
private static final int TYPE_FOOTER = 2; 
private static final int TYPE_Paid = 3; 
int id =0; 

CommentsAsyncTask Commentstask; 
Typeface custom_font; 
    public MyCustomAdapterDishes(Context context, ArrayList<Dishes> dish) { 
      this.dish = dish; 
      this.mContext = context; 
     custom_font = Typeface.createFromAsset(mContext.getAssets(), "fonts/HelveticaNeueLTArabic-Light.ttf"); 
    } 

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




     if(viewType == TYPE_HEADER) { 
      View v = LayoutInflater.from (mContext).inflate (R.layout.drawer_header, null); 
      return new HeaderViewHolder (v); 


     } 
     else if(viewType == TYPE_Paid&&id==0) { 
      View v = LayoutInflater.from (mContext).inflate (R.layout.drawer_header, null); 
      id=2; 
      return new HeaderViewHolder (v); 
     } 

     else if(viewType == TYPE_FOOTER) { 
      View v = LayoutInflater.from (mContext).inflate (R.layout.activity_chat, null); 
      return new FooterViewHolder (v); 
     } else if(viewType == TYPE_ITEM) { 
      View v = LayoutInflater.from (mContext).inflate (R.layout.dish_row_item, null); 
      v.setOnClickListener(this); 
      return new GenericViewHolder (v); 
     } 
     return null; 
    } 

@Override 
public int getItemViewType (int position) { 
    if(isPositionHeader (position)) { 
     return TYPE_HEADER; 
    } else if(isPositionFooter (position)) { 
     return TYPE_FOOTER; 
    } 
    else if(isPositionPaid (position)&&id<=1) { 
     return TYPE_Paid; 
    } 

    return TYPE_ITEM; 
} 




private boolean isPositionHeader (int position) { 
    return position == 0; 
} 

private boolean isPositionPaid (int position) { 

    return !(dish.get (position-1).getIsFree()); 
} 


private boolean isPositionFooter (int position) { 
    return position == dish.size() + 1; 
} 



private Dishes getItem (int position) { 
    return dish.get (position); 
} 



@Override 
public void onClick(final View view) { 

} 


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




     if(holder instanceof HeaderViewHolder) { 
      HeaderViewHolder headerHolder = (HeaderViewHolder) holder; 
     } 

    else if(holder instanceof FooterViewHolder) 

{ 
    FooterViewHolder footerHolder = (FooterViewHolder) holder; 




} 

else if(holder instanceof GenericViewHolder) { 
      Dishes currentItem = getItem(position - 1); 
      GenericViewHolder genericViewHolder = (GenericViewHolder) holder; 



      if(!currentItem.getIsFree()){ 
       genericViewHolder.arrow.setVisibility(View.INVISIBLE); 
       genericViewHolder.lock.setVisibility(View.VISIBLE); 
      } 
      //Download image using picasso library 
      Picasso.with(mContext).load(currentItem.getDishThumbnailUrl()) 
        .error(R.drawable.no_internet) 
        .tag(mContext) 
        .placeholder(R.drawable.no_spic) 
        .into(genericViewHolder.imageView); 

      genericViewHolder.DishName.setTypeface(custom_font); 
      genericViewHolder.DishName.setText(currentItem.getDishName()); 
      genericViewHolder.LikesCount.setText(currentItem.getDishLikesCount()); 

      View.OnClickListener clickListener = new View.OnClickListener() { 
       @Override 
       public void onClick(View view) { 
        // CustomViewHolder holder = (CustomViewHolder) view.getTag(); 
        // int position = holder.getPosition(); 

        //  Dishes di = dish.get(position); 
        // Toast.makeText(mContext, di.getDishName(), Toast.LENGTH_SHORT).show(); 
       } 
      }; 


} 



    } 

@Override 
    public int getItemCount() { 
      return dish.size() + 2; 
    } 

class FooterViewHolder extends RecyclerView.ViewHolder { 


    public FooterViewHolder (View itemView) { 
     super (itemView); 


    } 
} 

class HeaderViewHolder extends RecyclerView.ViewHolder { 
    TextView txtTitleHeader; 

    public HeaderViewHolder (View itemView) { 
     super (itemView); 
    // this.txtTitleHeader = (TextView) itemView.findViewById (R.id.txtHeader); 
    } 
} 

class GenericViewHolder extends RecyclerView.ViewHolder { 
    protected ImageView lock; 
    protected ImageView arrow; 
    protected ImageView imageView; 
    protected TextView DishName; 
    protected TextView LikesCount; 

    public GenericViewHolder (View view) { 
     super (view); 
     this.imageView = (ImageView) view.findViewById(R.id.thumbnail); 
     this.DishName = (TextView) view.findViewById(R.id.DishName); 
     this.LikesCount = (TextView) view.findViewById(R.id.LikesCount); 
     this.lock= (ImageView) view.findViewById(R.id.lock); 
     this.arrow=(ImageView) view.findViewById(R.id.arrow); 


     imageView.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 



      } 
     }); 

    } 





} 

} 

Answer 1

您正在使用

 if(!currentItem.getIsFree()){ 
      genericViewHolder.arrow.setVisibility(View.INVISIBLE); 
      genericViewHolder.lock.setVisibility(View.VISIBLE); 
     } 

但没有else块。由于回收站视图重用了行，因此您的箭头和锁的可见性将从重用行中获取，而不是从xml中获取。

尝试使用下面的代码，我想它会解决您的问题。否则，请详细说明您正在收到什么奇怪的数据。

 if(!currentItem.getIsFree()){ 
      genericViewHolder.arrow.setVisibility(View.INVISIBLE); 
      genericViewHolder.lock.setVisibility(View.VISIBLE); 
     }else{ 
      genericViewHolder.arrow.setVisibility(View.VISIBLE); 
      genericViewHolder.lock.setVisibility(View.INVISIBLE); 
     }