The saved data in my app stored using sqlite is not displayed when I go to a different activity deeper in the app and press the up button to go back to the original activity.
Here is the listfragment that is inflated by the listactivity.
Notice that I put the query in the onCreate to have it perform it again when going back to the activity.
package com.example.sample;
import java.util.ArrayList;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import com.actionbarsherlock.app.SherlockListFragment;
/**
* A list fragment representing a list of Courses. This fragment also supports
* tablet devices by allowing list items to be given an 'activated' state upon
* selection. This helps indicate which item is currently being viewed in a
* {@link CourseDetailFragment}.
* <p>
* Activities containing this fragment MUST implement the {@link Callbacks}
* interface.
*/
public class CourseListFragment extends SherlockListFragment {
SQLiteDatabase db;
DbHelper dbHelper;
boolean bool = false;
private static String courseName;
ArrayList<String> courseItems;
ArrayAdapter<String> adapter;
/**
* The serialization (saved instance state) Bundle key representing the
* activated item position. Only used on tablets.
*/
private static final String STATE_ACTIVATED_POSITION = "activated_position";
/**
* The fragment's current callback object, which is notified of list item
* clicks.
*/
private Callbacks mCallbacks = sDummyCallbacks;
/**
* The current activated item position. Only used on tablets.
*/
private int mActivatedPosition = ListView.INVALID_POSITION;
/**
* A callback interface that all activities containing this fragment must
* implement. This mechanism allows activities to be notified of item
* selections.
*/
public interface Callbacks {
/**
* Callback for when an item has been selected.
*/
public void onItemSelected(String id);
}
/**
* A dummy implementation of the {@link Callbacks} interface that does
* nothing. Used only when this fragment is not attached to an activity.
*/
private static Callbacks sDummyCallbacks = new Callbacks() {
@Override
public void onItemSelected(String id) {
}
};
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public CourseListFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dbHelper = new DbHelper(getActivity());
db = dbHelper.getReadableDatabase();
courseItems = new ArrayList<String>();
int layout = (Build.VERSION.SDK_INT >= 11) ? android.R.layout.simple_list_item_activated_1
: android.R.layout.simple_list_item_1;
adapter = new ArrayAdapter<String>(getActivity(), layout, courseItems);
// TODO: replace with a real list adapter.
setListAdapter(adapter);
if (bool) {
String[] projection = { DbHelper.COURSE_NAME };
Cursor c = db.query(DbHelper.TABLE_NAME, projection, null, null,
null, null, null);
c.moveToFirst();
while (c.moveToNext()) {
courseName = c
.getString(c.getColumnIndex(DbHelper.COURSE_NAME));
courseItems.add(courseName);
}
c.close();
adapter.notifyDataSetChanged();
}
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// Restore the previously serialized activated item position.
if (savedInstanceState != null
&& savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
setActivatedPosition(savedInstanceState
.getInt(STATE_ACTIVATED_POSITION));
}
}
public void addCourse() {
String[] projection = { DbHelper.COURSE_NAME };
Cursor c = db.query(DbHelper.TABLE_NAME, projection, null, null, null,
null, null);
c.moveToFirst();
while (c.moveToNext()) {
courseName = c.getString(c.getColumnIndex(DbHelper.COURSE_NAME));
courseItems.add(courseName);
}
c.close();
adapter.notifyDataSetChanged();
bool = true;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
// Activities containing this fragment must implement its callbacks.
if (!(activity instanceof Callbacks)) {
throw new IllegalStateException(
"Activity must implement fragment's callbacks.");
}
mCallbacks = (Callbacks) activity;
}
@Override
public void onDetach() {
super.onDetach();
// Reset the active callbacks interface to the dummy implementation.
mCallbacks = sDummyCallbacks;
}
@Override
public void onListItemClick(ListView listView, View view, int position,
long id) {
super.onListItemClick(listView, view, position, id);
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
mCallbacks.onItemSelected(null);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (mActivatedPosition != ListView.INVALID_POSITION) {
// Serialize and persist the activated item position.
outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
}
}
/**
* Turns on activate-on-click mode. When this mode is on, list items will be
* given the 'activated' state when touched.
*/
public void setActivateOnItemClick(boolean activateOnItemClick) {
// When setting CHOICE_MODE_SINGLE, ListView will automatically
// give items the 'activated' state when touched.
getListView().setChoiceMode(
activateOnItemClick ? ListView.CHOICE_MODE_SINGLE
: ListView.CHOICE_MODE_NONE);
}
public void setActivatedPosition(int position) {
if (position == ListView.INVALID_POSITION) {
getListView().setItemChecked(mActivatedPosition, false);
} else {
getListView().setItemChecked(position, true);
}
mActivatedPosition = position;
}
}
Edit updated for onoviewstaterestored
package com.example.sample;
import java.util.ArrayList;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import com.actionbarsherlock.app.SherlockListFragment;
/**
* A list fragment representing a list of Courses. This fragment also supports
* tablet devices by allowing list items to be given an 'activated' state upon
* selection. This helps indicate which item is currently being viewed in a
* {@link CourseDetailFragment}.
* <p>
* Activities containing this fragment MUST implement the {@link Callbacks}
* interface.
*/
public class CourseListFragment extends SherlockListFragment {
SQLiteDatabase db;
DbHelper dbHelper;
boolean bool = false;
private static String courseName;
ArrayList<String> courseItems;
ArrayAdapter<String> adapter;
/**
* The serialization (saved instance state) Bundle key representing the
* activated item position. Only used on tablets.
*/
private static final String STATE_ACTIVATED_POSITION = "activated_position";
/**
* The fragment's current callback object, which is notified of list item
* clicks.
*/
private Callbacks mCallbacks = sDummyCallbacks;
/**
* The current activated item position. Only used on tablets.
*/
private int mActivatedPosition = ListView.INVALID_POSITION;
/**
* A callback interface that all activities containing this fragment must
* implement. This mechanism allows activities to be notified of item
* selections.
*/
public interface Callbacks {
/**
* Callback for when an item has been selected.
*/
public void onItemSelected(String id);
}
/**
* A dummy implementation of the {@link Callbacks} interface that does
* nothing. Used only when this fragment is not attached to an activity.
*/
private static Callbacks sDummyCallbacks = new Callbacks() {
@Override
public void onItemSelected(String id) {
}
};
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public CourseListFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dbHelper = new DbHelper(getActivity());
db = dbHelper.getReadableDatabase();
courseItems = new ArrayList<String>();
int layout = (Build.VERSION.SDK_INT >= 11) ? android.R.layout.simple_list_item_activated_1
: android.R.layout.simple_list_item_1;
adapter = new ArrayAdapter<String>(getActivity(), layout, courseItems);
// TODO: replace with a real list adapter.
setListAdapter(adapter);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// Restore the previously serialized activated item position.
if (savedInstanceState != null
&& savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
setActivatedPosition(savedInstanceState
.getInt(STATE_ACTIVATED_POSITION));
}
}
@Override
public void onViewStateRestored(Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
String[] projection = { DbHelper.COURSE_NAME };
Cursor c = db.query(DbHelper.TABLE_NAME, projection, null, null, null,
null, null);
c.moveToFirst();
while (c.moveToNext()) {
courseName = c.getString(c.getColumnIndex(DbHelper.COURSE_NAME));
courseItems.add(courseName);
}
c.close();
adapter.notifyDataSetChanged();
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
// Activities containing this fragment must implement its callbacks.
if (!(activity instanceof Callbacks)) {
throw new IllegalStateException(
"Activity must implement fragment's callbacks.");
}
mCallbacks = (Callbacks) activity;
}
@Override
public void onDetach() {
super.onDetach();
// Reset the active callbacks interface to the dummy implementation.
mCallbacks = sDummyCallbacks;
}
@Override
public void onListItemClick(ListView listView, View view, int position,
long id) {
super.onListItemClick(listView, view, position, id);
// Notify the active callbacks interface (the activity, if the
// fragment is attached to one) that an item has been selected.
mCallbacks.onItemSelected(null);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (mActivatedPosition != ListView.INVALID_POSITION) {
// Serialize and persist the activated item position.
outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
}
}
/**
* Turns on activate-on-click mode. When this mode is on, list items will be
* given the 'activated' state when touched.
*/
public void setActivateOnItemClick(boolean activateOnItemClick) {
// When setting CHOICE_MODE_SINGLE, ListView will automatically
// give items the 'activated' state when touched.
getListView().setChoiceMode(
activateOnItemClick ? ListView.CHOICE_MODE_SINGLE
: ListView.CHOICE_MODE_NONE);
}
public void setActivatedPosition(int position) {
if (position == ListView.INVALID_POSITION) {
getListView().setItemChecked(mActivatedPosition, false);
} else {
getListView().setItemChecked(position, true);
}
mActivatedPosition = position;
}
}
I fixed it! I had to update the listview with the initially used addCourse method and then update it each time the activity resumes with the onViewStateRestored method. They both contain the same content in terms of what goes inside the method.
Here’s the code to my working list fragment.