Question

您好我搜索了SO并尽力而为但无法使其工作..我有一个列表视图，我正在加载带图像的手机联系人。下面是我的代码

public ProfileAdapter(Activity activity, int textViewResourceId, List<Profile> listCont,int renderer, String profileType) {
    super(activity, textViewResourceId, listCont);
    this.renderer = renderer;
    this.listCont = listCont;
    this.activity = activity;
    this.profileType = profileType;
}

public class ViewHolder {
    View rowView;
    public TextView textEmailId= null;
    public TextView textContNo= null;
    public TextView text= null;
    public ImageView photo= null;
    public int position;
}

@Override 
public View getView( int position, View convertView, ViewGroup parent) { 
    //View view = convertView; 
    ViewHolder holder;

    if (convertView == null) { 
        LayoutInflater inflater = (LayoutInflater) getContext() 
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
        convertView = inflater.inflate(renderer, null); 
        holder = new ViewHolder(convertView);
        holder.text = (TextView) convertView.findViewById(R.id.name); 
        holder.textContNo = (TextView) convertView.findViewById(R.id.contactno); 
        holder.textEmailId = (TextView) convertView.findViewById(R.id.emailId);  
        holder.photo = (ImageView ) convertView.findViewById(R.id.quickContactBadge1);  
        convertView.setTag(holder);
    }
    else {
        holder =(ViewHolder) convertView.getTag();       
        holder.position = position;
        Profile contact = listCont.get(position); 
        holder.text.setText(contact.getName()); 
        ImageView photo = (ImageView ) convertView.findViewById(R.id.quickContactBadge1);   
        photo.setTag(contact.getMobileNo()); 
        photo.setImageResource(R.drawable.stub_image);
        new LoadImage(photo).execute(contact.getMobileNo()); 
    } 
    return convertView;    
}

class LoadImage extends AsyncTask<String, Void, Bitmap>{ 
    // private final WeakReference<ImageView> viewReference;
    private ImageView img; 

    public LoadImage(ImageView img) { 
        //viewReference = new WeakReference<ImageView>( view );
        this.img=img;
    } 

    @Override 
    protected Bitmap doInBackground(final String... params) { 
        new QuickContactHelper(activity, img, (String) params[0]).addThumbnail(); 
        return null;
    }

    @Override 
    protected void onPostExecute(Bitmap bitmap) {
        // nothing
    }
}

问题是，我正在获取列表，但是当我开始滚动时图像正在加载，只有在滚动后图像稳定并处于正确位置...不确定哪里做错了，我希望图像应该加载在列表加载和图像应该在正确的位置...任何帮助表示赞赏

Answer 1

如果convertView == null，您似乎没有做任何事情。您需要在if和else中分配图片。

if (convertView == null) { 
    LayoutInflater inflater = (LayoutInflater) (getContext() 
.getSystemService(Context.LAYOUT_INFLATER_SERVICE)); 
    convertView = inflater.inflate(renderer, null); 

    holder = new ViewHolder(convertView);
    holder.text = (TextView) convertView.findViewById(R.id.name); 
    holder.textContNo = (TextView) convertView.findViewById(R.id.contactno); 
    holder.textEmailId = (TextView) convertView.findViewById(R.id.emailId);  
    holder.photo = (ImageView ) convertView.findViewById(R.id.quickContactBadge1);  

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

holder.position = position;
Profile contact = listCont.get(position); 
holder.text.setText(contact.getName()); 

ImageView photo = (ImageView ) convertView.findViewById(R.id.quickContactBadge1);   
photo.setTag(contact.getMobileNo()); 
photo.setImageResource(R.drawable.stub_image);

new LoadImage（photo）.execute（contact.getMobileNo（））;

Answer 2

您可以在适配器充气机中设置图像，以便滚动适配器在运行时修改。你应该在活动中设置图像

Answer 3

你只能在convertview！= null时启动AsynckTask。

要解决这个问题，只需将所有这些代码放在if语句之外：

   holder.position = position;
   Profile contact = listCont.get(position); 
   holder.text.setText(contact.getName()); 

   ImageView photo = (ImageView ) convertView.findViewById(R.id.quickContactBadge1);   
   photo.setTag(contact.getMobileNo()); 
   photo.setImageResource(R.drawable.stub_image);
   new LoadImage(photo).execute(contact.getMobileNo());

对于图片加载，我强烈推荐这个库：

Android-Universal-Image-Loader

希望这会对你有所帮助。

Android：错误地分配了Listview问题图像

3 个答案: