I've read several related posts and even posted and answer here but it seems like I was not able to solve the problem.
I have 3 Activities:
Act1 (main)
Act2
Act3
When going back and forth Act1->Act2 and Act2->Act1 I get no issues
When going Act2->Act3 I get no issues
When going Act3->Act2 I get occasional crashes with the following error: java.lang.IllegalStateException: trying to requery an already closed cursor android.database.sqlite.SQLiteCursor#.... This is a ListView cursor.
What I tried:
1. Adding stopManagingCursor(currentCursor);to the onPause() of Act2 so I stop managing the cursor when leaving Act2 to Act3
protected void onPause()
{
Log.i(getClass().getName() + ".onPause", "Hi!");
super.onPause();
saveState();
//Make sure you get rid of the cursor when leaving to another Activity
//Prevents: ...Unable to resume activity... trying to requery an already closed cursor
Cursor currentCursor = ((SimpleCursorAdapter)getListAdapter()).getCursor();
stopManagingCursor(currentCursor);
}
When returning back from Act3 to Act2 I do the following:
private void populateCompetitorsListView()
{
ListAdapter currentListAdapter = getListAdapter();
Cursor currentCursor = null;
Cursor tournamentStocksCursor = null;
if(currentListAdapter != null)
{
currentCursor = ((SimpleCursorAdapter)currentListAdapter).getCursor();
if(currentCursor != null)
{
//might be redundant, not sure
stopManagingCursor(currentCursor);
// Get all of the stocks from the database and create the item list
tournamentStocksCursor = mDbHelper.retrieveTrounamentStocks(mTournamentRowId);
((SimpleCursorAdapter)currentListAdapter).changeCursor(tournamentStocksCursor);
}
else
{
tournamentStocksCursor = mDbHelper.retrieveTrounamentStocks(mTournamentRowId);
}
}
else
{
tournamentStocksCursor = mDbHelper.retrieveTrounamentStocks(mTournamentRowId);
}
startManagingCursor(tournamentStocksCursor);
//Create an array to specify the fields we want to display in the list (only name)
String[] from = new String[] {StournamentConstants.TblStocks.COLUMN_NAME, StournamentConstants.TblTournamentsStocks.COLUMN_SCORE};
// and an array of the fields we want to bind those fields to (in this case just name)
int[] to = new int[]{R.id.competitor_name, R.id.competitor_score};
// Now create an array adapter and set it to display using our row
SimpleCursorAdapter tournamentStocks = new SimpleCursorAdapter(this, R.layout.competitor_row, tournamentStocksCursor, from, to);
//tournamentStocks.convertToString(tournamentStocksCursor);
setListAdapter(tournamentStocks);
}
So I make sure I invalidate the cursor and use a different one. I found out that when I go Act3->Act2 the system will sometimes use the same cursor for the List View and sometimes it will have a different one.
This is hard to debug and I was never able to catch a crashing system while debugging. I suspect this has to do with the time it takes to debug (long) and the time it takes to run the app (much shorter, no pause due to breakpoints).
In Act2 I use the following Intent and expect no result:
protected void onListItemClick(ListView l, View v, int position, long id)
{
super.onListItemClick(l, v, position, id);
Intent intent = new Intent(this, ActivityCompetitorDetails.class);
intent.putExtra(StournamentConstants.App.competitorId, id);
intent.putExtra(StournamentConstants.App.tournamentId, mTournamentRowId);
startActivity(intent);
}
Moving Act1->Act2 Act2->Act1 never gives me trouble. There I use startActivityForResult(intent, ACTIVITY_EDIT); and I am not sure - could this be the source of my trouble?
I would be grateful if anyone could shed some light on this subject. I am interested in learning some more about this subject.
Thanks,D.
I call this a 2 dimensional problem: two things were responsible for this crash:
1. I used startManagingCursor(mItemCursor); where I shouldn't have.
2. I forgot to initCursorAdapter() (for autocomplete) on onResume()
//#SuppressWarnings("deprecation")
private void initCursorAdapter()
{
mItemCursor = mDbHelper.getCompetitorsCursor("");
startManagingCursor(mItemCursor); //<= this is bad!
mCursorAdapter = new CompetitorAdapter(getApplicationContext(), mItemCursor);
initItemFilter();
}
Now it seems to work fine. I hope so...
Put this it may work for you:
#Override
protected void onRestart() {
// TODO Auto-generated method stub
super.onRestart();
orderCursor.requery();
}
This also works
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB) {
startManagingCursor(Cursor);
}
Related
I am working on an xtext Project where I have to customize the Scope Provider. I need to add up some possible candidates for the scope. The first part (getServiceInputs()) works fine but for the second one (addAll(sub.GetSubRecipeParameters()) not. Debugging showed that they get removed from its original source (sub) and can therefore not be retrieved again. When simply commenting out the addAll line the SubRecipeParameters remain in sub. Really dont know how to solve that, tried already some work arounds. Anyone with an Idea?
public class AutomationServiceDslScopeProvider extends AbstractAutomationServiceDslScopeProvider {
#Override
public IScope getScope(EObject context, EReference reference) {
if (context instanceof ServiceInvocationParameter
&& reference == AutomationServiceDslPackage.Literals.LITERAL) {
ServiceInvocation serviceCall = (ServiceInvocation) invocationParameter.eContainer();
ServiceDefinition calledService = serviceCall.getService();
List<ServiceParameterDefinition> candidates= calledService.getServiceInputs();
final EObject rootContainer = EcoreUtil.getRootContainer(context);
List<SubRecipeDefinition> subs = EcoreUtil2.getAllContentsOfType(rootContainer, SubRecipeDefinition.class);
for(SubRecipeDefinition sub:subs) {
for(RecipeStep step:sub.getRecipeSteps()) {
if(step.getName()==serviceCall.getName()) {
candidates.addAll(sub.getSubRecipeParameters());
}
}
}
return Scopes.scopeFor(candidates);
Thanks for any help!!
This is normal EMF behaviour if you move elements from one EList to another one. The solution is to create a new list e.g. new ArrayList<>() and also add the inputs there
List<ServiceParameterDefinition> candidates = new ArrayList<>();
candidates.addAll(calledService.getServiceInputs());
There are some database operations I need to execute before the end of the final attempt of my Hangfire background job (I need to delete the database record related to the job)
My current job is set with the following attribute:
[AutomaticRetry(Attempts = 5, OnAttemptsExceeded = AttemptsExceededAction.Delete)]
With that in mind, I need to determine what the current attempt number is, but am struggling to find any documentation in that regard from a Google search or Hangfire.io documentation.
Simply add PerformContext to your job method; you'll also be able to access your JobId from this object. For attempt number, this still relies on magic strings, but it's a little less flaky than the current/only answer:
public void SendEmail(PerformContext context, string emailAddress)
{
string jobId = context.BackgroundJob.Id;
int retryCount = context.GetJobParameter<int>("RetryCount");
// send an email
}
(NB! This is a solution to the OP's problem. It does not answer the question "How to get the current attempt number". If that is what you want, see the accepted answer for instance)
Use a job filter and the OnStateApplied callback:
public class CleanupAfterFailureFilter : JobFilterAttribute, IServerFilter, IApplyStateFilter
{
public void OnStateApplied(ApplyStateContext context, IWriteOnlyTransaction transaction)
{
try
{
var failedState = context.NewState as FailedState;
if (failedState != null)
{
// Job has finally failed (retry attempts exceeded)
// *** DO YOUR CLEANUP HERE ***
}
}
catch (Exception)
{
// Unhandled exceptions can cause an endless loop.
// Therefore, catch and ignore them all.
// See notes below.
}
}
public void OnStateUnapplied(ApplyStateContext context, IWriteOnlyTransaction transaction)
{
// Must be implemented, but can be empty.
}
}
Add the filter directly to the job function:
[CleanupAfterFailureFilter]
public static void MyJob()
or add it globally:
GlobalJobFilters.Filters.Add(new CleanupAfterFailureFilter ());
or like this:
var options = new BackgroundJobServerOptions
{
FilterProvider = new JobFilterCollection { new CleanupAfterFailureFilter () };
};
app.UseHangfireServer(options, storage);
Or see http://docs.hangfire.io/en/latest/extensibility/using-job-filters.html for more information about job filters.
NOTE: This is based on the accepted answer: https://stackoverflow.com/a/38387512/2279059
The difference is that OnStateApplied is used instead of OnStateElection, so the filter callback is invoked only after the maximum number of retries. A downside to this method is that the state transition to "failed" cannot be interrupted, but this is not needed in this case and in most scenarios where you just want to do some cleanup after a job has failed.
NOTE: Empty catch handlers are bad, because they can hide bugs and make them hard to debug in production. It is necessary here, so the callback doesn't get called repeatedly forever. You may want to log exceptions for debugging purposes. It is also advisable to reduce the risk of exceptions in a job filter. One possibility is, instead of doing the cleanup work in-place, to schedule a new background job which runs if the original job failed. Be careful to not apply the filter CleanupAfterFailureFilter to it, though. Don't register it globally, or add some extra logic to it...
You can use OnPerforming or OnPerformed method of IServerFilter if you want to check the attempts or if you want you can just wait on OnStateElection of IElectStateFilter. I don't know exactly what requirement you have so it's up to you. Here's the code you want :)
public class JobStateFilter : JobFilterAttribute, IElectStateFilter, IServerFilter
{
public void OnStateElection(ElectStateContext context)
{
// all failed job after retry attempts comes here
var failedState = context.CandidateState as FailedState;
if (failedState == null) return;
}
public void OnPerforming(PerformingContext filterContext)
{
// do nothing
}
public void OnPerformed(PerformedContext filterContext)
{
// you have an option to move all code here on OnPerforming if you want.
var api = JobStorage.Current.GetMonitoringApi();
var job = api.JobDetails(filterContext.BackgroundJob.Id);
foreach(var history in job.History)
{
// check reason property and you will find a string with
// Retry attempt 3 of 3: The method or operation is not implemented.
}
}
}
How to add your filter
GlobalJobFilters.Filters.Add(new JobStateFilter());
----- or
var options = new BackgroundJobServerOptions
{
FilterProvider = new JobFilterCollection { new JobStateFilter() };
};
app.UseHangfireServer(options, storage);
Sample output :
I am using a DevExpress MVC Pivot Grid and trying to work out some problems with the loading and saving of layouts. So far I have the following:
I have set my CustomActionRouteValues in the PivotGridSettings as follows:
CustomActionRouteValues = new { Controller = "Home", Action = "PivotGridCustomCallback" },
Which points to the following:
public ActionResult PivotGridCustomCallback(string action, string reportName)
{
if (string.IsNullOrEmpty(reportName))
{
reportName = "Report 1";
}
var settings = PivotGridLayoutHelper.DefaultPivotGridSettings;
if (action == "Save")
{
// TODO: Find a better solution than this. At the moment, if Save is called once, it is then called again every time the user changes the layout.. which is why we have the 'saved' variable here.
bool saved = false;
settings.AfterPerformCallback = (sender, e) =>
{
if (saved)
{
return;
}
SaveLayout(((MVCxPivotGrid)sender).SaveLayoutToString(), reportName);
saved = true;
};
}
else if (action == "Load")
{
// TODO: Find a better solution than this. At the moment, if Load is called once, it is then called again every time the user changes the layout.. which is why we have the 'loaded' variable here.
bool loaded = false;
string layoutString = LoadLayout(reportName);
if (!string.IsNullOrEmpty(layoutString))
{
settings.BeforeGetCallbackResult = (sender, e) =>
{
if (loaded)
{
return;
}
((MVCxPivotGrid)sender).LoadLayoutFromString(layoutString, PivotGridWebOptionsLayout.DefaultLayout);
loaded = true;
};
}
}
ViewBag.PivotSettings = settings;
return PartialView("PivotPartial");
}
The problem, as you can see in the code comments, is that after performing an action just one time, it then gets called EVERY time I make any sort of change. So, for example... say I load a report.. that's fine.. but then when I try expand something or add a field.. or do ANYTHING, nothing seems to happen on the UI.. and I figured out that's because immediately, this code gets called again:
settings.BeforeGetCallbackResult = (sender, e) =>
{
((MVCxPivotGrid)sender).LoadLayoutFromString(layoutString, PivotGridWebOptionsLayout.DefaultLayout);
};
That just keeps resetting the values to the saved layout, which means the UI looks like it's unresponsive when trying to change anything.
This is why I now have the boolean variable called loaded to check if it's already loaded. That works.. but it's an ugly hack.. because it's making unnecessary trips to the server each and every time the user does anything on the pivot grid.
Surely there must be a way to prevent these actions from firing all the time?
Looking for some help over here.
When i run this code (below), it crashes when i process it for the second time.
it crashes with an object reference not set.. on the session.outputstream
var session= new EASession(accessory, "net.gebe");
session.OutputStream.Open();
the second time session.outputstream is null. Even when disposing session.
Richard
public void PrintIt()
{
var _accessoryList = EAAccessoryManager.SharedAccessoryManager.ConnectedAccessories;
accessory = null;
foreach(var obj in _accessoryList)
{
if(obj.ProtocolStrings.Contains("net.gebe"))
{
accessory = obj;
//break;
}
}
if(accessory == null)
{
//tmg.InfoAlert ("No Printer");
return;
}
var session= new EASession(accessory, "net.gebe");
session.OutputStream.Open();
string str2 = "HELLO THERE PRINTER 1 2 3 4 5";
byte[] printdata2;
ASCIIEncoding encoding2 = new ASCIIEncoding();
printdata2 = encoding2.GetBytes(str2);
uint nlen2 = Convert.ToUInt32 (str2.Length+1);
session.OutputStream.Write(printdata2,nlen2 );
session.OutputStream.Close ();
session.Dispose ();
}
I got mine working now. What I did:
Save the session as a variable in the class
Only create the session if session is null
You may not want to call session.OutputStream.Close() after every print. At least it's something to keep in mind while debugging for your situation.
This will allow for multiple print jobs on the same page without blowing up. session.OutputStream was not null in this case.
I also found that the ViewDidLoad/Unload events weren't great for detecting when the device becomes available/unavailable via the EAAccessoryDidConnectNotification and EAAccessory DidDisconnectNotification observers. Instead I used ViewDidAppear/ViewDidDisappear. In those methods, I tear down the session, and when I come back in to print a new job, the session gets created and OutputStream is assigned.
Lastly, I wasn't getting events fired for my device via session.OutputStream.OnEvent. Not sure if it's my device, a MonoTouch bug, or just a generic bug of mine yet.
UPDATE: Check out this nicely wrapped implementation of AccessoryAdapter
You need to list the external accessories you're going to use in your Info.plist.
There is some documentation on this on apple's site:
http://developer.apple.com/library/ios/#featuredarticles/ExternalAccessoryPT/Introduction/Introduction.html#//apple_ref/doc/uid/TP40009502
Here is a screenshot of how to set this value in Info.plist:
http://screencast.com/t/AYmOWjf8wkL
(This is from here: https://bugzilla.xamarin.com/show_bug.cgi?id=1635#c1)
I have written an add in that takes the active document as a parameter. So each time that the active document has changed, I need to know. To do so, I wanted to use "Events.DocumentEvents.DocumentOpened" event of the DTE2 object. But the problem is that event is never get fired even though I change the active document.
The code snippet is as follows
public void OnConnection(object application, ext_ConnectMode connectMode, object addInInst, ref Array custom)
{
_applicationObject = (DTE2)application;
_applicationObject.Events.DocumentEvents.DocumentOpened += new _dispDocumentEvents_DocumentOpenedEventHandler(DocumentEvents_DocumentOpened);
...
}
void DocumentEvents_DocumentOpened(Document Document)
{
MessageBox.Show("Not called");
}
I have tried with DocumentEvents as well but no success. Any ideas?
I had just realized that I focused on the wrong event and thats why it was not fired. With the code below I got what I intended to. So instead of DocumentEvents, I had to use WindowEvents.
....
_applicationObject.Events.WindowEvents.WindowActivated += new _dispWindowEvents_WindowActivatedEventHandler(WindowEvents_WindowActivated);
}
void WindowEvents_WindowActivated(Window GotFocus, Window LostFocus)
{
if (ucCAST != null && GotFocus.Document != null)
((CAST)ucCAST).refreshCode(GotFocus.Document.Name);
}