我实现了一个简单的列表视图,其中包含一个选项,每次只选择一个项目,此功能正常工作。 我还有一个用于按Asc或Desc顺序对记录进行排序的按钮,当我选择一个记录时,在我对记录进行排序之后,旧记录的选择器保持在相同的旧位置,即使所选位置更新不同位置。
MainActivity:
public class MainActivity extends Activity
{
private ListView _listView;
private PersonAdapter _adapter;
private Button _sortBtn;
private List<Person> _data;
private int _sort;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
_listView = (ListView) findViewById(R.id.list);
_sortBtn = (Button) findViewById(R.id.sort_list_btn);
_sort = 1;
_data = new ArrayList<Person>();
_data.add(new Person("abc", "defg", 1));
_data.add(new Person("aaa", "defg", 12));
_data.add(new Person("ccc", "defg", 13));
_data.add(new Person("bb", "defg", 14));
_data.add(new Person("aa", "defg", 144));
_data.add(new Person("fff", "defg", 199));
_adapter = new PersonAdapter(this, _data);
_listView.setAdapter(_adapter);
_sortBtn.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Comparator<Person> sortById = Person.getComperatorByFirstName(_sort);
Collections.sort(_data, sortById);
_adapter.setData(_data);
_sort = -_sort;
}
});
}
public static class Person
{
public String _fName;
public String _lName;
public int _age;
public boolean _selected;
public Person(String fName, String lName, int age)
{
_fName = fName;
_lName = lName;
_age = age;
}
public static Comparator<Person> getComperatorByFirstName(final int ascendingFlag)
{
return new Comparator<Person>()
{
@Override
public int compare(Person patient1, Person patient2)
{
return patient1._fName.compareTo(patient2._fName) * ascendingFlag;
}
};
}
}
}
listView适配器
public class PersonAdapter extends BaseAdapter
{
private Context _con;
private List<Person> _data;
public PersonAdapter(Context context, List<Person> data)
{
_con = context;
_data = data;
}
@Override
public int getCount()
{
// TODO Auto-generated method stub
return _data.size();
}
@Override
public Person getItem(int position)
{
return _data.get(position);
}
@Override
public long getItemId(int position)
{
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
Holder h = null;
if (convertView == null)
{
h = new Holder();
convertView = LayoutInflater.from(_con).inflate(R.layout.item_layout, parent, false);
h._backgroundItem = (LinearLayout) convertView.findViewById(R.id.item_layout);
h._fName = (TextView) convertView.findViewById(R.id.f_name);
h._lName = (TextView) convertView.findViewById(R.id.l_name);
h._age = (TextView) convertView.findViewById(R.id.age);
convertView.setTag(h);
}
else
{
h = (Holder) convertView.getTag();
}
Person p = getItem(position);
h._fName.setText(p._fName);
h._lName.setText(p._lName);
h._age.setText(String.valueOf(p._age));
h._backgroundItem.setActivated(p._selected);
return convertView;
}
public void setData(List<Person> data)
{
_data = data;
notifyDataSetChanged();
}
private static class Holder
{
public LinearLayout _backgroundItem;
public TextView _fName;
public TextView _lName;
public TextView _age;
}
}
项目布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/item_layout"
android:layout_width="match_parent"
android:layout_height="48dp"
android:orientation="horizontal"
android:background="@drawable/list_selector"
android:weightSum="3" >
<TextView
android:id="@+id/f_name"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
<TextView
android:id="@+id/l_name"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
<TextView
android:id="@+id/age"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
</LinearLayout>
我已经尝试过使用clearChoices但是在排序之后我根本看不到选择器,我也尝试将选择模式从单一模式更改为无,然后再单一但没有任何成功。
答案 0 :(得分:1)
这是因为您正在切换列表项中的项目内容,但是单击被绑定到具有ListView的位置,因此它不会“更新”到项目的新位置。 我建议您在完成排序后以编程方式单击新项目。 获取所点击项目的ID
public int getItemPosition(long id)
{
for (int position=0; position<mList.size(); position++)
if (mList.get(position).getId() == id)
return position;
return 0;
}
然后在排序后点击
mList.performItemClick(
mList.getAdapter().getView(mActivePosition, null, null),
mActivePosition,
mList.getAdapter().getItemId(mActivePosition));
希望它有所帮助!
答案 1 :(得分:0)
我建议在选择项目时存储所选项目的ID,并在订购数据集后,搜索该ID并重新选择它。