实现可过滤的 Android 适配器不显示结果

Question

我有一个自定义适配器，用于过滤搜索结果。这适用于查找自动完成搜索标记。但是，它已被修改为在用户首次触摸搜索文本视图时显示最近搜索的项目。通过在搜索文本视图中将文本设置为 " 来启动筛选过程：

TextView.OnTouchListener onTouchListener = new View.OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
searchTextView.setText("");
recentSearches = true;
return false;
}
};

还有一个文本观察器：

TextWatcher onSearchSuggestionTextChanged = new TextWatcher()
{
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after)
{
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count)
{
if (s.length() > 0)
{
recentSearches = false;
}
}
@Override
public void afterTextChanged(Editable s)
{
if (!recentSearches && s.length() == 0)
{
cancelSearch();
}
}
};

搜索文本视图初始化如下：

searchTextView.setAdapter(new SearchAdapter(this));
searchTextView.addTextChangedListener(onSearchSuggestionTextChanged);
searchTextView.setOnTouchListener(onTouchListener);

SearchAdapter 是：

public class SearchAdapter extends BaseAdapter implements Filterable
{
private Context context;
private List<FoundItem> resultList = new ArrayList<FoundItem>();
private List<FoundItem> recentSearches = null;
public SearchAdapter(Context context)
{
this.context = context;
}
@Override
public int getCount()
{
return resultList.size();
}
@Override
public FoundItem getItem(int index)
{
return resultList.get(index);
}
@Override
public long getItemId(int position)
{
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
if (convertView == null)
{
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.simple_dropdown_item, parent, false);
}
FoundItem item = getItem(position);
((TextView) convertView.findViewById(R.id.text)).setText(item.name());
return convertView;
}
@Override
public Filter getFilter()
{
Filter filter = new Filter()
{
@Override
protected FilterResults performFiltering(CharSequence constraint)
{
FilterResults filterResults = new FilterResults();
if (constraint != null)
{
List<FoundItem> items = findSuggestions(context, constraint.toString());
// Assign the data to the FilterResults
filterResults.values = items;
filterResults.count = items.size();
}
else
{
filterResults.values = getRecentSearches();
filterResults.count = getRecentSearches().size();
}
return filterResults;
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results)
{
if (results != null && results.count > 0)
{
resultList = (List<FoundItem>) results.values;
notifyDataSetChanged();
}
else
{
notifyDataSetInvalidated();
}
}
};
return filter;
}
private List<FoundItem> findSuggestions(Context context, String query)
{
...
return foundItems;
}
private List<FoundItem> getRecentSearches()
{
...
return recentSearches;
}

适配器确实会获取最近搜索的结果，因此按预期调用performFiltering和publishResults方法，但随后仅调用一次getCount方法，并且不显示任何结果。相反，键入几个字符时，自动完成项目将按预期显示。请注意，最近的搜索不为空，并且在调用时searchTextView.getAdapter().getCount()文本更改前后，将返回正确的先前搜索次数。

那么为什么它不显示结果呢？有什么想法吗？

谢谢

Answer 1

手动我们必须调用

onSearchSuggestionTextChanged.onTextChanged()

在编辑文本的 ontouch(action_down( 内，如果其中的文本长度为零！

这将反过来触发过滤器的所有事件

TextView.OnTouchListener onTouchListener = new View.OnTouchListener()
{
@Override
public boolean onTouch(View v, MotionEvent event)
{
searchTextView.setText("");
recentSearches = true;
onSearchSuggestionTextChanged.onTextChanged("",0,0,0);
return false;
}
};