One of the benefits I thought of using CursorLoaders and Loadermanagers was that you didn't need to manually manage the lifecycle of the cursor. So I used a loadermanager to bind an adapter to an AutoCompleteTextView using the support package.
It works quite well except that it randomly throws an error saying "IllegalStateException - attempt to re-open an already closed object". Surely that's not supposed to happen if we're using the loader manager?
Here's the code:
package com.bhagwad.tennis;
import android.appwidget.AppWidgetManager;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.SimpleCursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter.CursorToStringConverter;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import com.bhagwad.tennis.TennisSchedule.TennisScheduleColumns;
public class WidgetConfiguration extends FragmentActivity implements OnClickListener, LoaderCallbacks<Cursor> {
Button mSaveWidget;
AutoCompleteTextView mPlayerName;
int mAppWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
String mSelection ="";
SimpleCursorAdapter mAdapter;
public static String PREFS = "com.bhagwad.tennis.appwidget";
public static final String PREFS_PREFIX_KEY = "prefix_";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.widget_configuration);
mPlayerName = (AutoCompleteTextView) findViewById(R.id.edit_filter);
mPlayerName.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (!s.equals(""))
mSelection = s.toString();
else
mSelection = "";
getSupportLoaderManager().restartLoader(0, null, WidgetConfiguration.this);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
});
// Set up the adapter
mAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, null, new String[] {TennisScheduleColumns.PLAYER_NAME}, new int[] {android.R.id.text1}, 0);
mAdapter.setCursorToStringConverter(new CursorToStringConverter() {
@Override
public CharSequence convertToString(Cursor c) {
return c.getString(c.getColumnIndexOrThrow(TennisScheduleColumns.PLAYER_NAME));
}
});
mPlayerName.setAdapter(mAdapter);
getSupportLoaderManager().initLoader(0, null, this);
}
@Override
public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) {
return new CursorLoader(this, TennisScheduleColumns.CONTENT_URI_PLAYERS, new String[] {TennisScheduleColumns._ID, TennisScheduleColumns.PLAYER_NAME}, TennisScheduleColumns.PLAYER_NAME + " LIKE ?", new String[] {"%"+mSelection+"%"}, null);
}
@Override
public void onLoaderReset(Loader<Cursor> arg0) {
mAdapter.swapCursor(null);
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
mAdapter.swapCursor(data);
}
}
Here's the error stack:
08-16 22:21:23.244: E/AndroidRuntime(25475): java.lang.IllegalStateException: attempt to re-open an already-closed object: android.database.sqlite.SQLiteQuery (mSql = SELECT _id, player_name FROM players WHERE (player_name LIKE ?))
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:33)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:82)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:164)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.database.sqlite.SQLiteCursor.onMove(SQLiteCursor.java:147)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.database.AbstractCursor.moveToPosition(AbstractCursor.java:178)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.database.CursorWrapper.moveToPosition(CursorWrapper.java:162)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.support.v4.widget.CursorAdapter.getItem(CursorAdapter.java:213)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.widget.AutoCompleteTextView.buildImeCompletions(AutoCompleteTextView.java:1113)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.widget.AutoCompleteTextView.showDropDown(AutoCompleteTextView.java:1072)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.widget.AutoCompleteTextView.updateDropDownForFilter(AutoCompleteTextView.java:950)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.widget.AutoCompleteTextView.onFilterComplete(AutoCompleteTextView.java:932)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.widget.Filter$ResultsHandler.handleMessage(Filter.java:285)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.os.Handler.dispatchMessage(Handler.java:99)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.os.Looper.loop(Looper.java:137)
08-16 22:21:23.244: E/AndroidRuntime(25475): at android.app.ActivityThread.main(ActivityThread.java:4507)
Any ideas on what could be wrong?
OnLoadFinished seems to get called sometimes with a dead cursor - if you put a test for isClosed() on the cursor you get passed you'll find it's closed in one in (some large number) attempts.
Unfortunately the 'standard' code to put in OnLoadFinished immediately does a changeCursor() on the adapter and, well, what follows is chaos, stackdumps, pestilence, etc.
My solution isn't any prettier than your try/catch.. ignore the bogus OnLoadFinished and risk the end user getting a blank UI.
来源：https://stackoverflow.com/questions/11999098/illegalstateexception-support-loadermanager-with-autocompletetextview