自动填充项目消失

Question

关于Android 2.2上的AutocompleteView的建议项,我有一个奇怪的问题.我正在使用自定义ArrayAdapter和Filter类实现.

当我输入AutocompleteView时,输入两个字符后会弹出建议下拉菜单,如以下屏幕截图所示:

当我输入第三个字符时,下拉列表消失:

输入第四个字符后,将再次显示建议下拉列表:

我不明白为什么输入的字符数量不均匀时下拉列表会消失.

在调试时我注意到,当输入偶数字符时,getView()被调用两次,但是对于不均匀的数量,则调用一次.这可能是导致错误行为的原因吗？

这是我的源代码:

public class AutoCompleteActivity extends Activity {

protected AutoCompleteTextView autoCompleteView;
protected AutoCompleteAdapter suggsAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.autocomp);

    autoCompleteView = (AutoCompleteTextView) findViewById(R.id.autocomplete);
    autoCompleteView.setAdapter(new AutoCompleteAdapter(this, android.R.layout.simple_dropdown_item_1line, new String[1]));
}

private class AutoCompleteAdapter extends ArrayAdapter implements Filterable {

    protected LayoutInflater mInflater;
    protected Filter filter;

    public AutoCompleteAdapter(Context context, int textViewResourceId, String[] items) {
        super(context, textViewResourceId, items);
        filter = new SuggestionsFilter();
        mInflater = LayoutInflater.from(context);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            v = mInflater.inflate(android.R.layout.simple_dropdown_item_1line, parent, false);
        }

        TextView tt = (TextView) v.findViewById(android.R.id.text1);
        tt.setText("Suggestion item");

        return v;
    }

    public Filter getFilter() {
        return filter;
    }

    private class SuggestionsFilter extends Filter {

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            return null;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            notifyDataSetChanged();
        }
    }
}

}

...和我的布局文件:

<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<!-- Pretty hint text, and maxLines -->
<AutoCompleteTextView android:id="@+id/autocomplete" 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:inputType="text"
    android:maxLines="1"
    android:imeOptions="actionSearch"
    android:layout_toLeftOf="@+id/spinner"  />

Answer 1

我找到了解决问题的方法.我没有设置results.count我的performFiltering方法.将此属性设置为例如results.count = 1解决了消失的建议项目的问题.