滚动时显示随机项目的getView

Posted 2023-04-19

【中文标题】滚动时显示随机项目的getView

【英文标题】：getView showing random items when scrolling

【发布时间】：2015-11-20 19:16:05

【问题描述】：

我的类 PlannerListAdapter 扩展了 BaseAdapter，我的 getView() 方法有 2 个问题。

1) 当我将适配器设置为列表视图时，一切正常，列表视图显示我列表中的所有元素，我向下滚动，我可以看到列表中的所有元素。但是当我向上滚动时，元素开始相互切换并且正在重复，而且它正在改变我的元素顺序，为什么会发生这种情况？

2) 在我的 BrandPlannersList 中，我有一个 String[] socialNetworks 对象。如果社交网络存在于 socialNetworks 中，我想更改社交网络（twitter、facebook、instagram）的默认图像。我认为我做得对，但它在不必要的时候改变了我在某些行中的一些图像。这是我的 getView 方法。

public View getView(int position, View convertView, ViewGroup parent) 
    // TODO Auto-generated method stub
    ViewHolder viewHolder;
    if (convertView == null) 
        LayoutInflater mInflater = (LayoutInflater)
                context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        convertView = mInflater.inflate(R.layout.planificacion_item, null);
        viewHolder = new ViewHolder();
        viewHolder.txtDate = (TextView) convertView.findViewById(R.id.date);
        viewHolder.txtTime = (TextView) convertView.findViewById(R.id.time);
        viewHolder.txtContent = (TextView) convertView.findViewById(R.id.content);
        viewHolder.txtStatus = (TextView) convertView.findViewById(R.id.status);
        viewHolder.txtBrandName = (TextView) convertView.findViewById(R.id.brandNameTextView);
        viewHolder.imgInstagram = (ImageView) convertView.findViewById(R.id.instagramPlanImg);
        viewHolder.imgTwitter = (ImageView) convertView.findViewById(R.id.twitterPlanImg);
        viewHolder.imgFacebook = (ImageView) convertView.findViewById(R.id.facebookPlanImg);
        viewHolder.contentImg = (ImageView) convertView.findViewById(R.id.image);
        convertView.setTag(viewHolder);
     else 
        viewHolder = (ViewHolder)item.getTag();
    
    viewHolder = (ViewHolder) convertView.getTag();
    viewHolder.txtDate.setText(brandPlannersList.get(position).publicationDate);
    viewHolder.txtTime.setText(brandPlannersList.get(position).publicationTime);
    viewHolder.txtBrandName.setText(brandPlannersList.get(position).brandName);

        if (brandPlannersList.get(position).status.equalsIgnoreCase("0")) 
            viewHolder.txtStatus.setText(R.string.to_publish);
         else 
            viewHolder.txtStatus.setText(R.string.published);
        
        viewHolder.txtContent.setText(brandPlannersList.get(position).content);
        if (brandPlannersList.get(position).image.trim().equalsIgnoreCase("")) 
            viewHolder.contentImg.setVisibility(View.GONE);
         else 
            Log.d("Imagen", brandPlannersList.get(position).image + "");
            new ImageLoadTask(context.getResources().getString(R.string.short_endpoint) + brandPlannersList.get(position).image, viewHolder.contentImg).execute();
        
//This is where i'm trying to change the social networks image
        if (brandPlannersList.get(position).socialNetworks.length > 0) 
            for (int i = 0; i < brandPlannersList.get(position).socialNetworks.length; i++) 
                Log.d("PlannerListAdapter", "Array de redes sociales en planner en posicion: "+position +" "+ Arrays.toString(brandPlannersList.get(position).getSocialNetworks()));
                if (brandPlannersList.get(position).socialNetworks[i].equalsIgnoreCase("twitter")) 
                    viewHolder.imgTwitter.setImageDrawable(twDrawable);
                
                if (brandPlannersList.get(position).socialNetworks[i].equalsIgnoreCase("instagram")) 
                    viewHolder.imgInstagram.setImageDrawable(inDrawable);
                
                if (brandPlannersList.get(position).socialNetworks[i].equalsIgnoreCase("facebook")) 
                    viewHolder.imgFacebook.setImageDrawable(fbDrawable);
                
            
        

    return convertView;

这是我的 viewHolder 类

static class ViewHolder
    TextView txtDate;
    TextView txtTime;
    TextView txtContent;
    TextView txtStatus;
    TextView txtBrandName;
    ImageView imgInstagram;
    ImageView imgTwitter;
    ImageView imgFacebook;
    ImageView contentImg;

如果您想查看其余方法：

public PlannerListAdapter(List<BrandPlanners> brandPlannersList, Drawable twDrawable, Drawable inDrawable, Drawable fbDrawable, Context context) 
    super();
    this.brandPlannersList = brandPlannersList;
    this.twDrawable = twDrawable;
    this.inDrawable = inDrawable;
    this.fbDrawable = fbDrawable;
    this.context = context;


@Override
public int getCount() 
    // TODO Auto-generated method stub
    return brandPlannersList.size();


@Override
public Object getItem(int arg0) 
    // TODO Auto-generated method stub
    return null;


@Override
public long getItemId(int arg0) 
    // TODO Auto-generated method stub
    return 0;

P.D.抱歉，我的英语不是最好的。

【问题讨论】：

为什么让 getItem 为空？

感谢您的评论，我已经将其更改为返回 brandPlannersList.get(i);但这不是问题

【参考方案1】：

问题已解决，我在适配器中添加了这两种方法：

@Override
public int getViewTypeCount()                  
return getCount();


@Override
public int getItemViewType(int position) 
return position;