所以我有一些不同的活动，它们将 SimpleCursorAdapter 用于 ListView。我现在主要担心的是内存泄漏等等。我需要确保光标在应该关闭的时候关闭。
我注意到，由于空指针异常，在我进行更改后重新运行代码时，我的应用程序崩溃了。
有人可以查看我的一项活动的代码，并告诉我光标未正确关闭是否存在问题？或者您看到的任何其他可能导致内存泄漏或 ANR 的问题？
RoutinesActivity.java：
package com.gauvion.gfit;
import android.annotation.SuppressLint;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
public class RoutinesActivity extends ListActivity {
private RoutinesDataSource datasource;
private SimpleCursorAdapter dataAdapter;
private boolean isEditing = false;
private Toast toast_deleted;
private String[] columns = new String[] { MySQLiteHelper.COLUMN_NAME };
private int[] to;
@SuppressLint("ShowToast")
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_routines);
getActionBar().setDisplayHomeAsUpEnabled(true);
toast_deleted = Toast.makeText(this, "", Toast.LENGTH_SHORT);
datasource = new RoutinesDataSource(this);
datasource.open();
Cursor cursor = datasource.fetchAllRoutines();
to = new int[] { R.id.listitem_routine_name };
dataAdapter = new SimpleCursorAdapter(this, R.layout.listitem_routine, cursor, columns, to, 0);
setListAdapter(dataAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.activity_routines, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
Cursor cursor = datasource.fetchAllRoutines();
switch (item.getItemId()) {
case android.R.id.home:
this.finish();
return true;
case R.id.button_routines_add:
Intent startRoutineAdd = new Intent(this, RoutineAddActivity.class);
this.startActivity(startRoutineAdd);
return true;
case R.id.button_routines_edit:
to = new int[] { R.id.listitem_routine_edit_name };
dataAdapter = new SimpleCursorAdapter(this, R.layout.listitem_routine_edit, cursor, columns, to, 0);
setListAdapter(dataAdapter);
isEditing = true;
invalidateOptionsMenu();
return true;
case R.id.button_routines_edit_done:
to = new int[] { R.id.listitem_routine_name };
dataAdapter = new SimpleCursorAdapter(this, R.layout.listitem_routine, cursor, columns, to, 0);
setListAdapter(dataAdapter);
isEditing = false;
invalidateOptionsMenu();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
menu.findItem(R.id.button_routines_edit).setVisible(!isEditing);
menu.findItem(R.id.button_routines_edit_done).setVisible(isEditing);
return true;
}
@Override
protected void onListItemClick(ListView l, View v, int position, long thisID)
{
Cursor cursor = ((SimpleCursorAdapter)l.getAdapter()).getCursor();
cursor.moveToPosition(position);
long id = cursor.getLong(cursor.getColumnIndex(MySQLiteHelper.COLUMN_ID));
String name = cursor.getString(cursor.getColumnIndex(MySQLiteHelper.COLUMN_NAME));
if (!isEditing) {
Intent startDaysActivity = new Intent(this, DaysActivity.class);
startDaysActivity.putExtra("routineDataID", id);
startDaysActivity.putExtra("routineDataName", name);
this.startActivity(startDaysActivity);
}
}
public void onClick(View view) {
ListView l = getListView();
int position = l.getPositionForView(view);
Cursor cursor = ((SimpleCursorAdapter)l.getAdapter()).getCursor();
cursor.moveToPosition(position);
long id = cursor.getLong(cursor.getColumnIndex(MySQLiteHelper.COLUMN_ID));
String name = cursor.getString(cursor.getColumnIndex(MySQLiteHelper.COLUMN_NAME));
switch (view.getId()) {
case R.id.button_routine_edit:
Intent startRoutineEdit = new Intent(this, RoutineEditActivity.class);
startRoutineEdit.putExtra("routineDataID", id);
startRoutineEdit.putExtra("routineDataName", name);
this.startActivity(startRoutineEdit);
break;
case R.id.button_routine_delete:
toast_deleted.setText(getString(R.string.toast_routine_deleted));
toast_deleted.show();
datasource.deleteRoutine(id);
onResume();
break;
}
}
@Override
protected void onResume() {
super.onResume();
datasource.open();
Cursor cursor = datasource.fetchAllRoutines();
dataAdapter.changeCursor(cursor);
}
@Override
protected void onPause() {
super.onPause();
datasource.close();
}
}