安卓：convertView ListView中總是空

Question

我想使用的ListView ViewHolder模式（我知道RecyclerView但我想它在ListView的！）。

我創造了它，但我注意到，在convertView getView（）總是空。每次調用getView（）。我究竟做錯了什麼？這一個

viewHolder = (ViewHolder) convertView.getTag(); 

：

public class ScheduleListAdapter extends BaseAdapter { 
    private LayoutInflater lInflater; 
    private List<ScheduleSubject> scheduleListItems; 

    public ScheduleListAdapter(Context context, List<ScheduleSubject> scheduleListItems) { 
     this.scheduleListItems = scheduleListItems; 
     lInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 

    @Override 
    public int getCount() { 
     return scheduleListItems.size(); 
    } 

    @Override 
    public Object getItem(int position) { 
     return scheduleListItems.get(position); 
    } 

    @Override 
    public long getItemId(int position) { 
     return position; 
    } 

    private static class ViewHolder { 
     TextView name, place; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder viewHolder; 
     if (convertView == null) { 
      convertView = lInflater.inflate(R.layout.schedule_item_show, parent, false); 
      viewHolder = new ViewHolder(); 
      viewHolder.name = (TextView) convertView.findViewById(R.id.schedule_item_name_textView); 
      viewHolder.place = (TextView) convertView.findViewById(R.id.schedule_item_place_textView); 
      convertView.setTag(viewHolder); 
     } else { 
      viewHolder = (ViewHolder) convertView.getTag(); 
     } 

     ScheduleSubject scheduleListItem = getScheduleListItem(position); 
     viewHolder.number.setText(String.valueOf(scheduleListItem.getLessonNumber())); 
     viewHolder.name.setText(scheduleListItem.getName()); 
     viewHolder.place.setText(scheduleListItem.getPlace()); 

     return convertView; 
    } 

    public ScheduleSubject getScheduleListItem(int position) { 
     return ((ScheduleSubject) getItem(position)); 
    } 
} 

Answer 1

嘗試用這個來更換此行

ViewHolder viewHolder; 

：

Holder viewHolder; 

而這一次

viewHolder = (Holder) convertView.getTag();