java - 试图重新查询一个已经关闭的游标 - 如何找到这个已经关闭的游标？

Question

我的应用程序在我触摸手机上的“后退”按钮(返回上一页)后抛出此错误:

11-06 19:16:56.016: E/AndroidRuntime(24018): java.lang.RuntimeException: Unable to resume activity {app.piotrek.learning/app.piotrek.learning.AddNewQuestion}: java.lang.IllegalStateException: trying to requery an already closed cursor  android.database.sqlite.SQLiteCursor@40f84ab8
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2567)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2595)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1183)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.os.Looper.loop(Looper.java:137)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.ActivityThread.main(ActivityThread.java:4575)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at java.lang.reflect.Method.invokeNative(Native Method)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at java.lang.reflect.Method.invoke(Method.java:511)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at dalvik.system.NativeStart.main(Native Method)
11-06 19:16:56.016: E/AndroidRuntime(24018): Caused by: java.lang.IllegalStateException: trying to requery an already closed cursor  android.database.sqlite.SQLiteCursor@40f84ab8
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.Activity.performRestart(Activity.java:4508)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.Activity.performResume(Activity.java:4531)
11-06 19:16:56.016: E/AndroidRuntime(24018):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2557)
11-06 19:16:56.016: E/AndroidRuntime(24018):    ... 10 more

我不知道怎么解决。几乎所有的游标都在 onCreate 函数中的“setOnClickListener”等函数中。我找不到错误在哪里。

编辑:这是我的代码:

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.Point;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.Display;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.SimpleCursorAdapter;
import android.widget.Spinner;

public class AddNewQuestion extends Activity {
    Context context;
    Database db;

    Button wczytajobrazek;
    Button addquestion;
    ImageView obrazekdoedycji;
    Bitmap wczytanyobrazek;
    Spinner spinnerSubject;
    Spinner spinnerTitles;
    EditText quest;
    EditText answ;
    Button addprzedmiot;
    Button addtitles;

    Display display;
    Point size;
    int screenWidth;
    int screenHeight;
    int IdOfSubjectfromSpinner;
    int IdOfTitlesfromSpinner;
    Bitmap bmp;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.dodajpytania);
        context = getApplicationContext();

        display = getWindowManager().getDefaultDisplay();
        size = new Point();
        screenWidth = display.getWidth();
        screenHeight = display.getHeight();

        quest = (EditText) findViewById(R.id.editText1);
        answ = (EditText) findViewById(R.id.editText2);
        wczytajobrazek = (Button) findViewById(R.id.button1);
        spinnerSubject = (Spinner) findViewById(R.id.spinner1);
        spinnerTitles = (Spinner) findViewById(R.id.spinner2);
        obrazekdoedycji = (ImageView) findViewById(R.id.imageButton1);
        addquestion = (Button) findViewById(R.id.add_question);
        addprzedmiot = (Button) findViewById(R.id.addprzedmiot);
        addtitles = (Button) findViewById(R.id.addTitles);


        db = new Database(getApplicationContext());
        db.open();

        fillSpinner(db.getAllEntriesSubjects(), spinnerSubject, DatabaseData.KEY_NAME);
        long data = spinnerSubject.getSelectedItemId();
        Log.v("ADDNEWQUESTION", "Wybrano: " + data);
        //fillSpinner(db.getAllEntriesTitles(), spinnerTitles);
        db.close();


        wczytajobrazek.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(
                        Intent.ACTION_PICK,
                        android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(intent, 0);
            }
        });

        addprzedmiot.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(context, AddNewSubjectOrTitle.class);
                startActivity(intent);
            }
        });
        addtitles.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(context, AddNewSubjectOrTitle.class);
                startActivity(intent);
            }
        });

        addquestion.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                String question = quest.getText().toString();
                String answer = answ.getText().toString();
                String img = "abc";
                String desc = "desc";
                Log.v("AddNewQuestion", "Question: " + question + " Answer: " + answer + " Save in (ID): Subject: " + IdOfSubjectfromSpinner + " Titles: " + IdOfTitlesfromSpinner);
                db.open();
                db.insertD(new Questions(question, answer, img, desc, IdOfTitlesfromSpinner).returnData(), DatabaseData.DB_THIRD_TABLE);
                db.close();
                quest.setText("");
                answ.setText("");
            }
        });


        spinnerSubject.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
                db.open();
                //String item = parent.getItemAtPosition(pos).toString();
                Cursor c = (Cursor)parent.getItemAtPosition(pos);
                startManagingCursor(c);
                String item = c.getString( c.getColumnIndex( DatabaseData.KEY_NAME ) );
                IdOfSubjectfromSpinner = c.getInt( c.getColumnIndex( DatabaseData.KEY_ID ) );
                Log.v("AddQuestion", "Wybrano: " + item + "("+ c.getInt(c.getColumnIndex(DatabaseData.KEY_ID)) +")");

                fillSpinner(db.getSomeEntriesTitles(c.getInt(c.getColumnIndex(DatabaseData.KEY_ID))), spinnerTitles, DatabaseData.KEY_TITLES_NAME);
                db.close();

            }
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

        spinnerTitles.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
                Cursor c = (Cursor)parent.getItemAtPosition(pos);
                startManagingCursor(c);

                //String item = c.getString( c.getColumnIndex( DatabaseData.KEY_NAME ) );   
                IdOfTitlesfromSpinner = c.getInt( c.getColumnIndex( DatabaseData.KEY_TITLES_ID ) );
            }
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });


    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);

        if (resultCode == RESULT_OK) {
            Uri targetUri = data.getData();
            File newfile = new File(targetUri.toString());
            try {
                wczytanyobrazek = MediaStore.Images.Media.getBitmap(this.getContentResolver(), targetUri);
                wczytanyobrazek = scaleImages(wczytanyobrazek, screenWidth/4, screenWidth/4);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            obrazekdoedycji.setImageBitmap(wczytanyobrazek);
        }
    }

    @Override
    protected void onStart(){
        super.onStart();
    }

    public void fillSpinner(Cursor cs, Spinner spinner, String dane){
        startManagingCursor(cs);

        SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_spinner_item, cs, new String[] {dane}, new int[] {android.R.id.text1});
        mAdapter.setDropDownViewResource(android.R.layout.simple_spinner_item);
        spinner.setAdapter(mAdapter);
    }


    public Bitmap scaleImages(Bitmap qBitmap, float nbwdth, float nbhght){
        float skalujSzer = ((float) nbwdth) / qBitmap.getWidth();
        float skalujWys = ((float) nbhght) / qBitmap.getHeight();
        Matrix matrixMAP1 = new Matrix();
        matrixMAP1.postScale(skalujSzer, skalujWys);

        qBitmap = Bitmap.createBitmap(qBitmap, 0, 0, qBitmap.getWidth(), qBitmap.getHeight(), matrixMAP1, true);

        return qBitmap;
    }

}

Answer 1

把这个它可能对你有用:

    @Override
    protected void onRestart() {
        // TODO Auto-generated method stub
        super.onRestart();

        cursorObject.requery();

    }