当我从设置活动返回到主要活动时出现此错误
java.lang.RuntimeException: Unable to resume activity {rewaya.books.ahadithviewer/rewaya.books.ahadithviewer.ViewerActivity}: java.lang.IllegalStateException: trying to requery an already closed cursor android.database.sqlite.SQLiteCursor@415708c0
HadithExpandableListFragment 的这段代码，我在其中调用数据库
package rewaya.books.ahadithviewer.fragment;
import rewaya.books.ahadithviewer.database.DatabaseAdapter;
import rewaya.books.ahadithviewer.R;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.app.Fragment;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ExpandableListView;
import android.widget.SimpleCursorTreeAdapter;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.Toast;
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@SuppressLint("NewApi")
public class HadithExpandableListFragment extends Fragment {
private OnItemSelectedListener listener;
private DatabaseAdapter mDbHelper;
public static Cursor mGroupsCursor;
private HadithExpandableListAdapter mAdapter;
ExpandableListView chapterListView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.hadith_expandablelist_fragment_layout,
container, false);
// Button button = (Button) view.findViewById(R.id.button1);
chapterListView=(ExpandableListView) view.findViewById(R.id.expandableView);
fillData();
return view;
}
public interface OnItemSelectedListener {
public void onChildSelected(String text);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (activity instanceof OnItemSelectedListener) {
listener = (OnItemSelectedListener) activity;
} else {
throw new ClassCastException(activity.toString()
+ " must implemenet MyListFragment.OnItemSelectedListener");
}
}
// May also be triggered from the Activity
public void updateDetail(int groupPosition, int childPosition,long id) {
// try
// {
String Paragraph = getText(groupPosition, childPosition,id);
listener.onChildSelected(Paragraph);
// }
// catch (Exception e){
//
// Toast.makeText(getActivity().getBaseContext(),
// "Exception" + Log.getStackTraceString(e),
// ).show();
// }
}
private String getText(int groupPosition, int childPosition,long id) {
// mDbHelper =new DatabaseAdapter(getActivity(),"hadith.db",1);
final Cursor cursor = (Cursor) mAdapter.getChild(groupPosition, childPosition);
final String accountGuid = cursor.getString(cursor.getColumnIndex("_id"));
// changeAccount(accountGuid, true);
String query = "SELECT [Hadith] FROM [Hadith] where HadithID=1";
Cursor selectedrow = mDbHelper.selectQuery(query);
String Paragraph = selectedrow.getString(selectedrow
.getColumnIndex("Hadith"));
// return Paragraph;
return accountGuid;
// TODO Auto-generated method stub
}
@SuppressWarnings("deprecation")
@SuppressLint("NewApi")
private View fillData() {
mDbHelper =new DatabaseAdapter(getActivity(),"hadith.db",1);
// mDbHelper.open();
mGroupsCursor = mDbHelper.selectQuery("SELECT [ChapterID] as _id,[ChapterName] FROM [Chapters] ");
getActivity().startManagingCursor(mGroupsCursor);
mGroupsCursor.moveToFirst();
// final ExpandableListView chapterListView = new ExpandableListView(getActivity());
mAdapter = new HadithExpandableListAdapter(mGroupsCursor, getActivity(),
android.R.layout.simple_expandable_list_item_1,
android.R.layout.simple_expandable_list_item_2,
new String[] { "ChapterName" },
new int[] { android.R.id.text1 },
new String[] { "Hadith" },
new int[] { android.R.id.text1 });
chapterListView.setAdapter(mAdapter);
chapterListView.setOnChildClickListener(new OnChildClickListener()
{
@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id)
{
chapterListView.setSelector(android.R.color.darker_gray);
updateDetail(groupPosition,childPosition,id );
// // System.out.println("Item: " + parent.getExpandableListAdapter().getChild(groupPosition, childPosition));
// Toast.makeText(getActivity().getBaseContext(),
// "Exception" + "Item: " + parent.getExpandableListAdapter().getChild(groupPosition, childPosition), childPosition).show();
//
// // ChildClick(childPosition);
return true;
}
});
mDbHelper.close();
return chapterListView;
}
public class HadithExpandableListAdapter extends SimpleCursorTreeAdapter {
public HadithExpandableListAdapter(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);
}
@SuppressLint("NewApi")
@Override
protected Cursor getChildrenCursor(Cursor groupCursor) {
Cursor childCursor = mDbHelper.selectQuery("SELECT [HadithID] as _id,[Hadith] ,ChapterID FROM [Hadith] where ChapterID=1 ");
getActivity().startManagingCursor(childCursor);
childCursor.moveToFirst();
return childCursor;
}
}
}
以及 DatabaseAdapter 的这段代码
package rewaya.books.ahadithviewer.database;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DatabaseAdapter extends SQLiteOpenHelper {
private Context mycontext;
private String DB_PATH = "data/data/rewaya.books.ahadithviewer/databases/";
private static String DB_NAME = "hadith.db";
private String DataBaseName;
// the extension may be .sqlite
// or .db
public SQLiteDatabase myDataBase;
public DatabaseAdapter(Context dummySectionFragment, String dbName, int dbVersion) {
super(dummySectionFragment, dbName, null, dbVersion);
DataBaseName =dbName;
this.mycontext = dummySectionFragment;
boolean dbexist = checkdatabase();
if (dbexist) {
} else {
System.out.println("Database doesn't exist");
try {
createdatabase();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void createdatabase() throws IOException {
boolean dbexist = checkdatabase();
if (dbexist) {
} else {
this.getReadableDatabase();
try {
copydatabase();
} catch (IOException e) {
throw new Error(e.toString());
}
}
}
private boolean checkdatabase() {
boolean checkdb = false;
try {
String myPath = DB_PATH + DataBaseName;
File dbfile = new File(myPath);
checkdb = dbfile.exists();
} catch (SQLiteException e) {
System.out.println("Database doesn't exist");
}
return checkdb;
}
private void copydatabase() throws IOException {
// Open your local db as the input stream
InputStream myinput = mycontext.getAssets().open(DataBaseName);
// Path to the just created empty db
@SuppressWarnings("unused")
String outfilename = DB_PATH + DataBaseName;
// Open the empty db as the output stream
OutputStream myoutput = new FileOutputStream(
"data/data/rewaya.books.ahadithviewer/databases/"+DataBaseName);
// transfer byte to inputfile to outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myinput.read(buffer)) > 0) {
myoutput.write(buffer, 0, length);
}
// Close the streams
myoutput.flush();
myoutput.close();
myinput.close();
}
public void open() {
// Open the database
String mypath = DB_PATH + DataBaseName;
myDataBase = SQLiteDatabase.openDatabase(mypath, null,
SQLiteDatabase.OPEN_READWRITE);
}
public synchronized void close() {
myDataBase.close();
super.close();
}
public Cursor selectQuery(String query)
{
String myPath = DB_PATH + DataBaseName;
//myData = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
myDataBase = SQLiteDatabase.openDatabase(myPath,null, SQLiteDatabase.CREATE_IF_NECESSARY);
Cursor mCursor =myDataBase.rawQuery(query, null);
mCursor.moveToFirst();
myDataBase.close();
return mCursor;
}
public Cursor getEmpByName(int Id)
{
SQLiteDatabase db=this.getReadableDatabase();
Cursor c = db.rawQuery("select * from GaddHyatek_Book where ID=1", null);
return c;
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}