我已将设备更新为Android ICS（4.0.3） 我有一个活动，其中包含一个列表视图，其中填入了从数据库中读取的数据。 使用ResourceCursorAdapter的扩展名将数据排列在列表视图中。
列表加载并显示在屏幕上后，我按下主屏幕以显示主屏幕。然后我从最近恢复我的应用程序（长按主屏幕）突然我得到以下异常：
05-10 15:49:17.925: E/AndroidRuntime(10721): Caused by: android.database.StaleDataException: Attempted to access a cursor after it has been closed.
05-10 15:49:17.925: E/AndroidRuntime(10721): at android.database.BulkCursorToCursorAdaptor.throwIfCursorIsClosed(BulkCursorToCursorAdaptor.java:75)
05-10 15:49:17.925: E/AndroidRuntime(10721): at android.database.BulkCursorToCursorAdaptor.requery(BulkCursorToCursorAdaptor.java:144)
05-10 15:49:17.925: E/AndroidRuntime(10721): at android.database.CursorWrapper.requery(CursorWrapper.java:186)
05-10 15:49:17.925: E/AndroidRuntime(10721): at android.app.Activity.performRestart(Activity.java:4505)
05-10 15:49:17.925: E/AndroidRuntime(10721): at android.app.Activity.performResume(Activity.java:4531)
05-10 15:49:17.925: E/AndroidRuntime(10721): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2446)
在我的案例中，我已经阅读过操作系统的行为，并且光标似乎无效。 问题是尽管我已经注册了一个DataSetObserver，但是从未调用onInvalidated方法，并且在崩溃之前也没有调用Activity的方法（比如onResume，onRestart）。代码甚至没有到达适配器中的bindView。
你可以帮帮我吗？ 如果需要，我可以提供更多信息和相关代码。提前致谢
这里的代码，对不起，如果它是一团糟但我只是在微调之前使其工作：
public class CallLogsList extends Activity implements Runnable,
OnItemClickListener {
// ... various declaration here
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case CALLLOGS_LOAD_DONE:
loadCurrCallLogsList(true);
break;
case SHOW_ALL_LOG:
case SHOW_MISSED_LOG:
case SHOW_OUTGOING_LOG:
case SHOW_INCOMING_LOG:
// - set the adapter
if (null == mCad) {
// the first time the adapter need to be called
mCad = new CallLogsCursorAdapter(mContext, mDataCursor);
mCallLogsListView.setAdapter(mCad);
} else {
mCad.changeCursor(mDataCursor);
mCad.notifyDataSetChanged();
}
break;
} // end of switch ctrl structure
return;
} // end of method handleMessage
}; // end of Handler object
/**
* The following inner class implements the custom adapter to contain the
* call log entries as read from the database
*
*/
class CallLogsCursorAdapter extends ResourceCursorAdapter {
Cursor mCallLogCursor = null;
CallLogDataSetObserver mLogDataObserver = null;
/**
* Class constructor
*
* @param context
* @param c
*/
public CallLogsCursorAdapter(Context context, Cursor c) {
super(context, R.layout.recent_calls_list_item, c);
mLogDataObserver = new CallLogDataSetObserver();
mCallLogCursor = c;
mCallLogCursor.registerDataSetObserver(mLogDataObserver);
return;
} // end of class constructor
/**
* This method binds an existing view to the data pointed to by the
* cursor
*/
@Override
public void bindView(View view, Context context, Cursor cursor) {
// ... bind data to the view here
} // end of method bindView
/**
* This method inflates the new view from the specified resource Such
* resource has been passed to the super class in the call at the parent
* class constructor we did in this derived class
*/
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
View view = super.newView(context, cursor, parent);
// ... create the view
return view;
} // end of method newView
/**
/**
* The data set observer for the data used by this adapter
*/
private class CallLogDataSetObserver extends DataSetObserver {
@Override
public void onChanged() {
return;
} // end of method onChanged
@Override
public void onInvalidated() {
if( null != mCallLogCursor ) {
// TODO: Remove this call coz the UI can get stuck
// if the call log is too long. Just ask for a new
// cursor asynchronously
mCallLogCursor.requery();
}
return;
} // end of method onInvalidated
} // end of class inner class CallLogDataSetObserver
} // end of class CallLogsCursorAdapter
/**
* This method is called the first time the activity is created
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
Log.d(THIS_FILE, "Enter onCreate");
super.onCreate(savedInstanceState);
// ... initialization code here
loadCurrCallLogsList(false);
return;
} // end of method onCreate
/**
* This method loads the current communication list
*/
private synchronized void loadCurrCallLogsList(final boolean fromPullDown) {
if (false == fromPullDown) {
showLoadingView(true);
}
// start the loader thread
Thread loader = new Thread(this);
loader.start();
return;
} // end of method loadCurrCommunicationsList
/**
* This method is called when the activity is going to be destroyed
*/
@Override
protected void onDestroy() {
if (null != database) database.close();
database = null;
if (mDataCursor != null) mDataCursor.close();
mDataCursor = null;
// call the super class onDestroy method
super.onDestroy();
}
/**
* This method create the menu for the activity
*
* @param menu
*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.in_call_log_list_menu, menu);
return super.onCreateOptionsMenu(menu);
} // end of method onCreateOptionsMenu
/**
* This method is called when the menu is going to be shown
*/
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
if (false == CordlessApplication.getInstance().canUseJungoApi()) {
menu.findItem(R.id.menu_item_edit).setEnabled(false);
} else {
// enable the edit item in the menu if the list is not empty
menu.findItem(R.id.menu_item_edit).setEnabled(
null != mCad && !mCad.isEmpty());
}
return super.onPrepareOptionsMenu(menu);
} // end of method onPrepareOptionsMenu
/**
* This method is called when the user click on an item in the menu
*
* @param item
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
item.setChecked(true);
// Handle item selection
switch (item.getItemId()) {
case R.id.sub_menu_item_all:
mCurrentLogView = CURR_LIST_ALL_LOG;
mListHeader.setText(R.string.all_calls_log_header_txt);
loadCurrCallLogsList(false);
break;
case R.id.sub_menu_item_in_only:
mCurrentLogView = CURR_LIST_INCOMING_LOG;
mListHeader.setText(R.string.received_calls_log_header_txt);
loadCurrCallLogsList(false);
break;
case R.id.sub_menu_item_out_only:
mCurrentLogView = CURR_LIST_OUTGOING_LOG;
mListHeader.setText(R.string.dialled_calls_log_header_txt);
loadCurrCallLogsList(false);
break;
case R.id.sub_menu_item_miss_only:
mCurrentLogView = CURR_LIST_MISSED_LOG;
mListHeader.setText(R.string.missed_calls_log_header_txt);
loadCurrCallLogsList(false);
break;
case R.id.menu_item_edit:
startModifyActivity();
break;
default:
return super.onOptionsItemSelected(item);
}
return (true);
} // end of method onOptionsItemSelected
/**
* This method is called when the user comes back to this activity from a
* sub activity
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (Activity.RESULT_OK != resultCode)
return;
switch (requestCode) {
case DialingUtils.REQ_CODE_ADD_NEW_CONTACT: // pass through
case DialingUtils.REQ_CODE_UPDATE_EXISTING_CONTACT:
// refresh the call log list
mCad.getCursor().requery();
mCad.notifyDataSetChanged();
break;
case DialingUtils.REQ_CODE_PICK_CONTACT:
DialingUtils.updateExistingContact(this, data.getData(),
mCallerInfo.mPhoneNumber, true);
break;
}
} // end of method onActivityResult
/**
/**
* This method load a filter version of the call logs
*
* @param filter
*/
private void loadFilteredData(final int filter) {
if( null != mDataCursor ) mDataCursor.close();
mDataCursor = null;
// see whether it is needed to recover the database
if (null == database) {
database = new DBAdapter(mContext);
database.open();
}
// read all the call logs from the database
mDataCursor = database.getFilteredCallLogs(filter);
return;
} // end of method loadFilterData
/**
* This method is called when the user press a key on the device We use this
* method to handle the press on the back key
*/
@Override
/**
* This method is called in order to load the data from the
* local database in a separated thread
*/
@Override
public synchronized void run() {
Looper.prepare();
synchronized (MyConstants.mCallLogsMutex) {
switch (mCurrentLogView) {
case CURR_LIST_ALL_LOG:
loadFilteredData(0);
mHandler.sendEmptyMessage(SHOW_ALL_LOG);
break;
case CURR_LIST_MISSED_LOG:
loadFilteredData(CallLog.Calls.MISSED_TYPE);
mHandler.sendEmptyMessage(SHOW_MISSED_LOG);
break;
case CURR_LIST_OUTGOING_LOG:
loadFilteredData(CallLog.Calls.OUTGOING_TYPE);
mHandler.sendEmptyMessage(SHOW_OUTGOING_LOG);
break;
case CURR_LIST_INCOMING_LOG:
loadFilteredData(CallLog.Calls.INCOMING_TYPE);
mHandler.sendEmptyMessage(SHOW_INCOMING_LOG);
break;
}
} // end of synch block
} // end of method run
} // end of class CallLogsList
答案 0 :(得分：9)
我找到了原因，解决方案如下： 当你必须处理Cursor或Database时，请避免使用Activity.managedQuery（...）和Activity.startManagingCursor（...）。 文档说他们确实被弃用了。
答案 1 :(得分：0)
而不是使用Activity.ManagedQuery()使用Context.Query()
string[] projection = new string[] { CalendarContract.Calendars.InterfaceConsts.Id };
string selection = CalendarContract.Calendars.InterfaceConsts.Id + "=?";
string[] selectionArgs =new string[]{Constants.CALENDAR_ID.ToString()};
var cursor = m_ContentResolver.Query(calendarUri, projection, selection, selectionArgs, null);
来自Xamarin App的示例，日历操作
答案 2 :(得分：0)
使用
Activity.getContentResolver().query()
而不是
Activity.managedQuery()