首先显示错误的图像，然后在滚动列表视图期间显示正确的图像

Question

我在我的应用程序中使用带有图像的列表视图。但每当我 滚动列表首先显示错误的图像，然后显示正确的图像 图像正在显示。我不知道为什么会这样。我 认为已经加载的图像正在显示，直到设置位置。 这是我的适配器类，请帮助我哪里出错了

  public class MySimpleArrayAdapter extends ArrayAdapter<String> {
    private Activity context;
    ArrayList<String> namear,msgar,idar,profimage,postimage,commentsnum,objectid,urlString;
  ImageLoader imageLoader;
  Bitmap[] bitdata;

  public MySimpleArrayAdapter(Activity c,int i,ArrayList<String> postpic, ArrayList<String> names,ArrayList<String> msg,ArrayList<String> id,ArrayList<String> proimg,Bitmap[] bit,ArrayList<String> comment,ArrayList<String> objid,ArrayList<String> web) {

      super(c, i, names);
    Log.e("adapter","adap");
    this.context = c;
    this.namear = names;
    this.msgar = msg;
    this.idar = id;
    this.profimage=proimg;
    this.postimage=postpic;
    this.bitdata=bit;
    this.commentsnum=comment;
    this.objectid=objid;
    this.urlString=web;
   this.imageLoader = new ImageLoader(context);
  }

  @Override
  public View getView(final int position, View convertView, ViewGroup parent) {
  View rowView=convertView;
  ViewHolder holder = new ViewHolder();
      if(convertView == null) {
  LayoutInflater inflator = getLayoutInflater();
  rowView = inflator.inflate(R.layout.walldata, null);

  holder.name1 = (TextView) rowView.findViewById(R.id.name);
  holder.message1 = (TextView) rowView.findViewById(R.id.msg);
  holder.profimg= (ImageView) rowView.findViewById(R.id.profile_pic);
  holder.postimg= (ImageView) rowView.findViewById(R.id.picpost);
  holder.comments = (TextView) rowView.findViewById(R.id.comment);
  rowView.setTag(holder);
     Log.e("user",idar.get(position));
      }
      else
         {
          holder = (ViewHolder) rowView.getTag();
         }
    Log.e("adapter","adap");
    holder.name1.setText(namear.get(position));
    if(msgar.get(position)!=""){
        holder.message1.setText(msgar.get(position));

    }
    else
    {
        holder.message1.setVisibility(View.GONE);
    }
    if(!postimage.get(position).equals(""))
    {try{
         imageLoader.DisplayImage(postimage.get(position).replace(" ", "%20"), holder.postimg) ;

    }
    catch(Exception e){
        e.printStackTrace();
    }
    }
    else
    {
         holder.postimg.setVisibility(View.GONE);
    }
    try{
      imageLoader.DisplayImage(profimage.get(position).replace(" ", "%20"), holder.profimg) ;
    }
    catch(Exception e){
       e.printStackTrace();
    }

    holder.comments.setText(commentsnum.get(position)+"\t"+"Comments");
    holder.comments.setOnClickListener(new OnClickListener() {


        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent myintent=new Intent(Wall.this,Comments.class);
            myintent.putExtra("name", namear.get(position));
            myintent.putExtra("profimg", profimage.get(position));
            myintent.putExtra("message", msgar.get(position));
            myintent.putExtra("postpic", postimage.get(position));
            myintent.putExtra("objectid", objectid.get(position));
            myintent.putExtra("commentsnum",commentsnum.get(position));
            myintent.putExtra("webservice", urlString.get(position));
            startActivity(myintent);

        }
    });

    return rowView;
  }

}
public class ViewHolder{
    TextView name1, message1,comments;
    ImageView profimg,postimg;
}

Answer 1

确保在 getView 方法中尽早将 ImageView 中的图像设置为 null。由于 ListView 正在重复使用列表项，因此将显示旧的，直到设置了新的。