android listview在滚动背景图像时停止一秒钟

我使用的是自定义列表视图（其中有一个图像和文本框作为布局），所有数据都是从类对象和图像表单web检索的，所有的事情都运行得非常好，唯一的事情是在emulator中列表视图没有显示任何异常行为，但当我将其部署到设备上时，listview并没有像它应该做的那样滚动。它只敲了一下，整个列表视图的背景图像消失，然后在滚动结束时出现。我应该做的是调用和填充列表视图数据的代码

public void item_display(){
    String[] separated = eventIDForList.split(",");
    final List_class ObjListClass[] = new List_class[separated.length];
    for(int i=0;i<separated.length;i++){
        String temp=separated[i];
        eventIdVal=Integer.parseInt(temp);
        Log.d("events id for displaying id",eventIdVal+"");
        ObjListClass[i]=new List_class();
        ObjListClass[i]=new List_class(FBEvents.getInstance().object_info.get(eventIdVal).fbEventId,FBEvents.getInstance().object_info.get(eventIdVal).fbPic,"Title:  "+FBEvents.getInstance().object_info.get(eventIdVal).fbName,"desc :"+FBEvents.getInstance().object_info.get(eventIdVal).fbDescription,"location :"+FBEvents.getInstance().object_info.get(eventIdVal).fbLocation,FBEvents.getInstance().object_info.get(eventIdVal).fbAttending_count);

   }
    List_class_adapter adapter = new List_class_adapter(this,
            R.layout.listview_item_row, ObjListClass);
    listView1 = (ListView)findViewById(R.id.listView2);

    listView1.setAdapter(adapter);

   // View header = (View)getLayoutInflater().inflate(R.layout.listview_header_row, null);
   // listView1.addHeaderView(header);
   // listView1.setAdapter(adapter);
    listView1.setOnItemClickListener(new OnItemClickListener()
    {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long duration)
            {

            Log.d("position val",position+"");
            eventIdForDetails=ObjListClass[position].eventId;
            Log.d("String val",eventIdForDetails);
            eventdetails(view);

            }
    });  

public void item_display（）{
String[]separated=eventIDForList.split（“，”）；
最终列表_类ObjListClass[]=新列表_类[separated.length]；
对于（int i=0；i我认为您应该使用
线程
或
异步任务
。这将避免延迟，并在另一个
线程
中运行后台进程到底发生了什么事？listView的背景是黑色的？不，它的白色或用户定义的颜色，但当我开始滚动时，背景会消失，只要我是滚动>查看Ajmal Salims答案。在
getView（）
-方法中下载和创建图像就像乞求性能不佳。这应该异步完成，并且您可能还应该实现某种缓存。在我调用适配器的主要活动中或在适配器中添加asyntask的位置>
public class List_class_adapter extends ArrayAdapter<List_class>{

Context context;
int layoutResourceId;   
List_class data[] = null;

public List_class_adapter(Context context, int layoutResourceId, List_class[] data) {
    super(context, layoutResourceId, data);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data = data;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    ListHolder holder = null;

    if(row == null)
    {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new ListHolder();
        holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
        holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);
        holder.txtTitle2 = (TextView)row.findViewById(R.id.txtTitle2);
        holder.txtTitle3 = (TextView)row.findViewById(R.id.txtTitle3);
        holder.txtTitle4 = (TextView)row.findViewById(R.id.txtTitle4);

        row.setTag(holder);

    }
    else
    {
        holder = (ListHolder)row.getTag();
    }

    List_class list_class = data[position];
    String url = list_class.pic;           
    Drawable image =ImageOperations(this,url);
    holder.txtTitle.setText(list_class.title);
    holder.imgIcon.setImageDrawable(image);
    holder.txtTitle2.setText(list_class.description);
    holder.txtTitle3.setText(list_class.startdate);
    holder.txtTitle4.setText(list_class.attending_count);

    return row;
}

static class ListHolder
{
    ImageView imgIcon;
    TextView txtTitle;
    TextView txtTitle2;
    TextView txtTitle3;
    TextView txtTitle4;


}




public Object fetch(String address) throws MalformedURLException,
IOException {
    URL url = new URL(address);
    Object content = url.getContent();
    return content;
}  

private Drawable ImageOperations(List_class_adapter list_class_adapter, String url) {
    try {
        InputStream is = (InputStream) this.fetch(url);
        Drawable d = Drawable.createFromStream(is, "src");
        return d;
    } catch (MalformedURLException e) {
        return null;
    } catch (IOException e) {
        return null;
    }
}