我的应用程序中有两个片段的布局（一个listFragment包含标题，另一个包含详细信息。）
启动后一切正常。每次单击listfragment中的条目时，都会更新Detail-Fragment。
然而，在改变方向之后，每个新的细节片段都只是在旧细节片段上打开。 （由于我的声誉很低，我无法发布任何截图，对不起。）
我的活动包含两个片段：
/**
* A fragment representing a list of Items.
* <p />
* Large screen devices (such as tablets) are supported by replacing the ListView
* with a GridView.
* <p />
*/
public class MedicationTitlesFragment extends ListFragment
implements AdapterView.OnItemClickListener, SearchView.OnQueryTextListener, SearchView.OnCloseListener, LoaderManager.LoaderCallbacks<Cursor> {
/**
* The Adapter which will be used to populate the ListView/GridView with
* Views.
*/
//private ListAdapter mAdapter;
private static final String TAG = MedicationTitlesFragment.class.getSimpleName();
private static final int LOADER_ID = 1;
//private OnFragmentInteractionListener mListener;
private OnMedicationSelectedListener mMedicationSelectedListener;
/**
* The fragment's ListView/GridView.
*/
private ListView mListView;
private LoaderManager.LoaderCallbacks<Cursor> mLoaderCallbacks;
private SearchView mSearchView;
private String mCurFilter;
private SimpleCursorAdapter mAdapter;
static final String[] RPINFO_SUMMARY_PROJECTION = new String[] {
RpEntry.Columns.SNAME, RpEntry.Columns._ID, RpEntry.Columns.ONAME, RpEntry.Columns.PHZNR,
RpEntry.Columns.ZNR_FORMATTED, RpEntry.Columns.RSIGN_P1, RpEntry.Columns.RSIGN_P5
};
// TODO: Rename and change types of parameters
public static MedicationTitlesFragment newInstance(String param1, String param2) {
MedicationTitlesFragment fragment = new MedicationTitlesFragment();
Bundle args = new Bundle();
return fragment;
}
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public MedicationTitlesFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
Log.d(TAG, "entered onCreate");
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_item_list, container, false);
// Set the adapter
mListView = (ListView) view.findViewById(android.R.id.list);
((AdapterView<ListAdapter>) mListView).setAdapter(mAdapter);
// Set OnItemClickListener so we can be notified on item clicks
mListView.setOnItemClickListener(this);
setEmptyText("Keine Einträge");
return view;
}
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mMedicationSelectedListener = (OnMedicationSelectedListener) activity;
//this.getListView().setOnItemClickListener(this);
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mMedicationSelectedListener = null;
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
Log.d(TAG, "entered onListItemClick");
getListView().setItemChecked(position, true);
Uri rpDetailUri = Uri.parse(RpInfoContentProvider.CONTENT_URI + "/" + id);
Log.d(TAG, "rpDetailUri: " + rpDetailUri.toString());
mMedicationSelectedListener.onMedicationSelected(rpDetailUri);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (null != mMedicationSelectedListener) {
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
//mListener.onFragmentInteraction(DummyContent.ITEMS.get(position).id);
}
}
/**
* The default content for this Fragment has a TextView that is shown when
* the list is empty. If you would like to change the text, call this method
* to supply the text it should use.
*/
public void setEmptyText(CharSequence emptyText) {
View emptyView = mListView.getEmptyView();
if (emptyText instanceof TextView) {
((TextView) emptyView).setText(emptyText);
}
}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
// This is called when a new Loader needs to be created. This
// sample only has one Loader, so we don't care about the ID.
// First, pick the base URI to use depending on whether we are
// currently filtering.
Uri baseUri = null;
if (null != mCurFilter)
baseUri = Uri.withAppendedPath(RpEntry.CONTENT_URI, Uri.encode(mCurFilter));
else
baseUri = RpEntry.CONTENT_URI;
// Now create and return a CursorLoader that will take care of
// // creating a Cursor for the data being displayed.
return new CursorLoader(
getActivity().getBaseContext(),
baseUri,
RPINFO_SUMMARY_PROJECTION,
null,
null,
RpEntry.Columns.SNAME + " COLLATE LOCALIZED ASC");
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
// Der Loader hat fertig geladen, die Daten können nun im UI angezeigt werden
// switch to handle multiple loaders
switch(loader.getId()) {
case LOADER_ID:
mAdapter.swapCursor(data);
}
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
mAdapter.swapCursor(null);
}
@Override
public boolean onClose() {
if (!TextUtils.isEmpty(mSearchView.getQuery())) {
mSearchView.setQuery(null, true);
}
return true;
}
@Override
public boolean onQueryTextSubmit(String query) {
Log.d(TAG, "entered onQueryTextSubmit");
return true;
}
@Override
public boolean onQueryTextChange(String newText) {
Log.d(TAG, "enteredOnQueryTextChanged");
// Called when the action bar search text has changed. Update
// the search filter, and restart the loader to do a new query
// with this filter.
mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
getLoaderManager().restartLoader(LOADER_ID, null, mLoaderCallbacks);
return true;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnMedicationSelectedListener {
// TODO: Update argument type and name
public void onMedicationSelected(Uri uri);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setEmptyText("Keine Arzneimitteldaten geladen");
setHasOptionsMenu(true);
String[] dataColums = { RpEntry.Columns.SNAME };
int[] viewIDs = { android.R.id.text1};
mAdapter = new SimpleCursorAdapter(
getActivity().getBaseContext(),
android.R.layout.simple_list_item_1,
null,
dataColums,
viewIDs,
0);
this.setListAdapter(mAdapter);
// this.setListShown(false);
mLoaderCallbacks = this;
LoaderManager lm = getLoaderManager();
lm.initLoader(LOADER_ID, null, mLoaderCallbacks);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// Inflate the menu; this adds items to the action bar if it is present.
Log.d(TAG, "entered onCreateOptionsMenu");
// Place an action bar item for searching.
MenuItem item = menu.add("Search");
item.setIcon(android.R.drawable.ic_menu_search);
item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
SearchView sv = new SearchView(getActivity());
sv.setOnQueryTextListener(this);
item.setActionView(sv);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()) {
case R.id.action_settings:
Log.d(TAG, "action_settings clicked");
Toast.makeText(getActivity().getApplicationContext(), "Einstellungen",
Toast.LENGTH_LONG).show();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public static class MySearchView extends SearchView {
public MySearchView(Context context) {
super(context);
}
// The normal SearchView doesn't clear its search text when
// collapsed, so we will do this for it.
@Override
public void onActionViewCollapsed() {
setQuery("", false);
super.onActionViewCollapsed();
}
}
}
非常感谢！
答案 0 :(得分：0)
请确保您的活动onCreate中有
void onCreate(Bundle savedState) {
...
if(savedState == null) {
// add your details fragment
} else {
// do not add your details fragment it's already there
}
}