【发布时间】:2016-09-22 09:24:08
【问题描述】:
我想在两种情况下刷新我的适配器,但什么也没发生。首先我尝试调用
adapter.clear();
adapter.addAll(filteredList); //filtered list is a new list to show on adapter
adapter.notifyDataSetChanged();
第二次我尝试通过notifyDataSetInvalidated();在我的过滤器中刷新它
我的适配器类:
public class DatabaseAdapter extends ArrayAdapter<Exhibition> {
private Context context;
private List<Exhibition> records;
private List<Exhibition>filterRecords;
private Dao<Exhibition, Integer> exhibitionDAO;
private ViewHolder viewHolder;
private SearchFilter searchFilter;
public DatabaseAdapter(Context context,
int itemView,
List objects,
Dao<Exhibition, Integer> exhibitionDAO) {
super(context, itemView, objects);
this.context=context;
this.records = new ArrayList<>(objects);
this.filterRecords=new ArrayList<>(objects);
this.searchFilter=new SearchFilter();
this.exhibitionDAO = exhibitionDAO;
}
@Override
public View getView(int position, View view, ViewGroup parent) {
final Exhibition exhibition= records.get(position);
if(view==null){
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view= inflater.inflate(R.layout.museum_list_item_layout,parent,false);
viewHolder = new ViewHolder();
view.setTag(viewHolder);
}else
viewHolder = (ViewHolder) view.getTag();
viewHolder.eventName=(TextView)view.findViewById(R.id.list_item);
viewHolder.eventName.setText(exhibition.getName());
return view;
}
@Override
public int getCount() {
return records.size();
}
@Override
public Filter getFilter() {
if(searchFilter==null)
searchFilter=new SearchFilter();
return searchFilter;
}
public class ViewHolder{
TextView eventName;
}
private class SearchFilter extends Filter {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
List<Exhibition> list;
if (constraint == null || constraint.length() == 0){
list = new ArrayList<Exhibition>(records);
results.values = list;
results.count = list.size();}
else{
try{
list = exhibitionDAO.queryBuilder().where().like("name","%"+constraint+"%").query();
synchronized (list){
results.values=list;
results.count=list.size();}
}
catch (SQLException e){e.printStackTrace();}}
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
filterRecords = (ArrayList<Exhibition>)results.values;
notifyDataSetChanged();
clear();
int count = filterRecords.size();
for(int i = 0; i<count; i++){
add(filterRecords.get(i));
notifyDataSetInvalidated();
}
}
}
}
更新:我通过添加两个函数解决了我的问题:
public void addAllItems(List< Exhibition> exhibitions){
records.clear();
records.addAll(exhibitions);
}
public void addItems(List<Exhibition> exhibitions){
records.addAll(exhibitions);
}
一个是刷新所有项目,第二个是添加到列表中。我想这不是非常有效的解决方案。如果有人给我提示如何改进,我将不胜感激。
【问题讨论】:
-
使用 ArrayAdapter 作为基类的原因是什么?
ArrayAdapter.clear()使数据集失效,之前notifyDataSetChanged的意义何在? ...与ArrayAdapter.add()的故事相同 -
我认为我应该通过 adapter.clear() 删除适配器中的所有项目,而不是添加新项目并通知更改。
-
@Override public int getCount() { return records.size(); } ... public View getView(int position, View view, ViewGroup parent) { final Exhibition exhibition= records.get(position);您没有使用AA.getCount的默认实现...并且您没有在AA.getView()实现中使用AA.getItem()...所以使用AA.clear和AA.add没有意义 -
删除 getCount() 后 AA.clear 和 AA.add 工作并且列表正在刷新,但它在使用过滤器时通过抛出 IndexOutOfBoundsException:| 崩溃
-
那么你有一些想法如何刷新列表并离开getCount?
标签: android refresh adapter notify notifydatasetchanged