问题
Hey, I am trying to convert my existing App using Tabhost and Activities to a Action Bar based App with fragments. In this process a ran into the issue to implement Expandable Lists.
I haven´t found any simple example in the internet on how to implement this Expandable List. As ExpandableListActivity has no counterpart for fragments I think I need to use and extend ListFragment but as I am quite new to android I haven´t got any clue how. :)
I would be glad if someone could shed some light on how to use an expandable list with fragments.
Thanks.
Attached is also a snippet of my existing code.
Fragment 1 with two spinners already
public class Configurator_Fragment extends SherlockListFragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (container == null) {
}
final View v = inflater.inflate(R.layout.configurator_layout,
container, false);
final Spinner spinner = (Spinner) v
.findViewById(R.id.spinner1);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
getActivity(), R.array.array1,
android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
final Spinner spinner2 = (Spinner) v.findViewById(R.id.spinner2);
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(
getActivity(), R.array.array2,
android.R.layout.simple_spinner_item);
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(adapter2);
return v;
}
}
FragmentActivity
public class TabActivity extends SherlockFragmentActivity {
ViewPager mViewPager;
TabsAdapter mTabsAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tab_navigation);
if (savedInstanceState == null) {
Fragment newFragment = new Configurator_Fragment();
Fragment newFragment2 = new SecondFragment();
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.pager, newFragment, "First");
ft.add(R.id.pager, newFragment2, "Second");
ft.commit();
}
getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.Tab tab1 = getSupportActionBar().newTab().setText("Fragment 1");
ActionBar.Tab tab2 = getSupportActionBar().newTab().setText("Fragment 2");
mViewPager = (ViewPager)findViewById(R.id.pager);
mTabsAdapter = new TabsAdapter(this, getSupportActionBar(), mViewPager);
mTabsAdapter.addTab(tab1, Configurator_Fragment.class, null);
mTabsAdapter.addTab(tab2, SecondFragment.class, null);
if (savedInstanceState != null) {
getSupportActionBar().setSelectedNavigationItem(savedInstanceState.getInt("index"));
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("index", getSupportActionBar().getSelectedNavigationIndex());
}
public static class TabsAdapter extends FragmentPagerAdapter implements ViewPager.OnPageChangeListener, ActionBar.TabListener {
private final Context mContext;
private final ActionBar mBar;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
private FragmentTransaction mCurTransaction = null;
static final class TabInfo {
private final Class<?> clss;
private final Bundle args;
TabInfo(Class<?> _class, Bundle _args) {
clss = _class;
args = _args;
}
}
public TabsAdapter(FragmentActivity activity, ActionBar bar, ViewPager pager) {
super(activity.getSupportFragmentManager());
mContext = activity;
mBar = bar;
mViewPager = pager;
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}
public void addTab(ActionBar.Tab tab, Class<? extends Fragment> clss, Bundle args) {
TabInfo info = new TabInfo(clss, args);
tab.setTag(info);
tab.setTabListener(this);
mTabs.add(info);
mBar.addTab(tab);
notifyDataSetChanged();
}
@Override
public int getCount() {
return mTabs.size();
}
@Override
public Fragment getItem(int position) {
TabInfo info = mTabs.get(position);
return Fragment.instantiate(mContext, info.clss.getName(), info.args);
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
mBar.setSelectedNavigationItem(position);
}
@Override
public void onPageScrollStateChanged(int state) {
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
Object tag = tab.getTag();
for (int i=0; i<mTabs.size(); i++) {
if (mTabs.get(i) == tag) {
mViewPager.setCurrentItem(i);
}
}
}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}
}
回答1:
A couple disclaimers first...
1) I haven't used ABS, so I'm not sure what changes that would make.
2) My ExpandableListView is backed by a database, not arrays. I say this becasue it looks like you are using arrays. I post this anyway in the hopes it might still provide you with some direction.
That said, I've done it simply by extending Fragment.
public class EventListFragment extends Fragment {
private AttendanceDB mDbHelper;
public static Cursor mGroupsCursor;
private MyExpandableListAdapter mAdapter;
private String mGroup;
private String mChild;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.explistfragment, container, false);
header = (TextView) v.findViewById(R.id.header1);
header.setText(R.string.event_header);
return v;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Bundle extras = getIntent().getExtras();
mGroup = extras.getString("Group");
mChild = extras.getString("Child");
mDbHelper = new AttendanceDB(getActivity());
mDbHelper.open();
fillData(mGroup, mChild);
}
private void fillData(String group, String child) {
ExpandableListView lv;
mGroupsCursor = mDbHelper.fetchGroup(group);
getActivity().startManagingCursor(mGroupsCursor);
mGroupsCursor.moveToFirst();
lv = (ExpandableListView) getActivity().findViewById(R.id.explist);
mAdapter = new MyExpandableListAdapter(mGroupsCursor, getActivity(),
R.layout.explistlayout,
R.layout.explistlayout1,
new String[] { "_id" },
new int[] { android.R.id.text1 },
new String[] { child },
new int[] { android.R.id.text1 });
lv.setAdapter(mAdapter);
}
public class MyExpandableListAdapter extends SimpleCursorTreeAdapter {
public MyExpandableListAdapter(Cursor cursor, Context context,
int groupLayout, int childLayout, String[] groupFrom,
int[] groupTo, String[] childrenFrom, int[] childrenTo) {
super(context, cursor, groupLayout, groupFrom, groupTo,
childLayout, childrenFrom, childrenTo);
}
@Override
protected Cursor getChildrenCursor(Cursor groupCursor) {
Cursor childCursor = mDbHelper.fetchChildren(mGroup, groupCursor
.getString(groupCursor
.getColumnIndex(AttendanceDB.EVENT_ROWID)));
getActivity().startManagingCursor(childCursor);
childCursor.moveToFirst();
return childCursor;
}
}
}
来源：https://stackoverflow.com/questions/11072683/android-expandable-list-within-fragments