Regularly during my application run, I get
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at mx.managers::SystemManager/stageEventHandler()[C:\autobuild\3.4.0\frameworks\projects\framework\src\mx\managers\SystemManager.as:5649]
This is the full stack trace. Obviously, I guess there is something wrong, but I can't understand what.
Is there any way for me to find the origin of that bad behaviour ?
EDIT
Having added my SDK sources to my debugger, I can now say precisely which line it is :
private function stageEventHandler(event:Event):void
{
if (event.target is Stage)
mouseCatcher.dispatchEvent(event); // This is line 5649
}
mouseCatcher is indeed null. The current event target is indeed a Stage object, and event type contains the "deactivate" String. As event occurs at application startup (before I try to do any kind of user interaction), I guess it's a kind of initialization bug, but where ? and why ?
Look at the source code, this is always your best option. The 3.4 SDK is open source (datavisualization and the flash player itself aside) and you probably already have the source for it in your FlashBuilder/FlexBuilder install/sdks folder. Use grep or windows grep to find the file in question (or find, whatever floats your boat). Open the SystemManager file and check what's happening at that line, check for calls to the method (if it's public use grep again, if it's private you just need to look within the SystemManager). Try to understand why it gets to this point, as pointed out by some others it's likely a timing related issue where you're trying to access something before it has been assigned, in this case the SystemManager, you probably need to defer whatever action you're taking that is causing the error to a later part of the life-cycle (if you're using initialize event or pre-initialize try on creationComplete instead since that will be dispatched after the createChildren method is called).
Note: Mine is located here
C:\CleanFS\SDKs\flex\3.4.0.9271\frameworks\projects\framework\src\mx\managers
In my copy of SystemManager with the version of the SDK I have that line number doesn't make any sense since it's a block closure not an executable line so you'll have to look at your specific version.
It looks like you are using the Flex 3.4 SDK. Are you listening for the ADDED_TO_STAGE event when the application loads? Or doing anything with the Stage object on load? If so, you might be hitting a bug specific to the 3.4 SDK:
http://bugs.adobe.com/jira/browse/SDK-23332
The most obvious solution is to swap out the 3.4 SDK for a later version (3.4A, 3.5 or 3.6). You can do that here: http://opensource.adobe.com/wiki/display/flexsdk/Download+Flex+3
All of your code should be backwards compatable with the newer Flex 3 SDKs.
Related
I have import a dump file from .NET Core process into WinDbg.
There is an event handle
0:000> !handle 3760 f
Handle 0000000000003760
Type Event
Attributes 0
GrantedAccess 0x1f0003:
Delete,ReadControl,WriteDac,WriteOwner,Synch
QueryState,ModifyState
HandleCount 2
PointerCount 65534
Name <none>
Object specific information
Event Type Auto Reset
Event is Waiting
How can I use the SOS extension to analyze this event? To see where it is created in managed code?
As Event Type is Auto Reset, imho you should look at the instances of AutoResetEvent class.
Not sure about Core but in Framework you can take NetExt extension and perform queries to the heap.
AutoResetEvent has a private field waitHandle with IntPtr to the handle you observe.
So, after running !windex NexExt query will look like:
!wfrom -type System.Threading.AutoResetEvent where (waitHandle == 0000000000003760) select $addr(), $tohexstring(waitHandle)
If NetExt doesn't work with Core you can dump all instances on AutoResetEvents into text file like this and then find your event there.
.logopen c:\temp\autoresetevents.txt
.foreach (obj {!dumpheap -type AutoResetEvent -short}) {!do obj}
.logclose
With this approach you'll be able to find managed object that corresponds to the handle.
You'll also be able to see the roots with !GCRoot. But you won't be able to see where it is created.
You'll need to search around.
Or you'll need to use different approach, something with PerfView allocation tracing or maybe some special breakpoints.
I'm just looking into CefSharp and am confused about NewScreenshot. I've found lots of references to it as well as example code, but none of it works. I found it marked as obsolete in the 63.0 docs...
Has NewScreenshot been removed? If so, what replaces it (how can I tell that the screen has rendered)? For my purposes a blocking (non-async) method would work fine.
Update:
Searching the source for the latest version of CefSharp I find no reference to NewScreenshot.
I started with the Minimal Example that #amaitland referred to. I made a few changes, adapting it for my use. As part of that change I moved the Shutdown() call to the program's destructor.
When I ran the project I received a mystifying error about calling Shutdown() from a thread different than the thread from which Initialize() was called.
Looking through the code I saw ScreenshotAsync and, as I wasn't (knowingly) using another thread, suspected it may be involved. I looked for another way to get my SVG image and found NewScreenshot. Which of course didn't solve my problem, which was that the GC was running my destructor in a different thread (I had no idea that could happen).
At any rate, by this time I'd shucked ScreenshotAsync for NewScreenshot which is how I ended up here.
I set a breakpoint in my handler (which I haven't included as it's never called). Here's what I hope is the relevant code. I've omitted the init code but I believe it's unchanged from the example.
public static void Main()
{
private const string url = "https://www.google.com/";
browser = new ChromiumWebBrowser();
browser.Paint += OnBrowserPaint;
browser.Load(url)
Console.ReadKey();
}
In stepping through the code in the debugger, I set a breakpoint on browser.Load(url). If I examine browser.Paint, I find errors:
Here's the tooltip for DeclaringMethod:
I have no idea if this is related to my event handler not firing, but want to point it out in the event it is involved.
I appreciate your other suggestions but feel I need to find out why an event that should be firing is not.
I'll be happy to reduce and upload the project if it will help. Oh, and thanks for your help!
I've installed collective.quickupload on a blank Plone 4.1 site,
and noticed that when you add a quickupload portlet, kss calls for field validation (plone.app.form.kss), getSite function will return a FormlibValidation object, which cause the quickupload vocabularies crash.
The traceback is here: http://pastebin.com/nvwChpZd
My question is:
Is that (getSite function returns a FormlibValidation object) a bug or intended behaviour ?
Solution to fix/work around/make collective.quickupload work ?
getSite() returns the nearest component site (where local utilities can be stored), which really just means whatever was last set with setSite(), which usually happens on traversal.
Most of the time, the only traversal hook that calls setSite() is the one that's triggered when you traverse over the Plone site. But I think the old KSS inline form validation machinery used (uses?) a hack that creates a local component site on the fly (in a view) and sets that as the local site during the remainder of the request so that it can override certain things.
You can disable validation (e.g. disable the relevant KSS file in portal_kss) or fix c.quickupload to check whether the result of getSite() is an ISiteRoot. If it isn't, it should be acquisition-wrapped, so you can do aq_parent(site) (or maybe site.parent) to get the parent in a loop until you find an ISiteRoot.
I'm getting error while running a game I created with flex.
I know there has been some question about this, but my case is quite weird. I created a simple typing game that is running OK on my computer, but when I tried to deploy it online to facebook, I got those errors. I used code from the tutorial from adobe here http://www.adobe.com/devnet/facebook/articles/flex_fbgraph_pt4.html to deploy my flex game to facebook
This is the error message:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at FacebookUserStatusWeb/init()
at FacebookUserStatusWeb/___FacebookUserStatusWeb_Application1_creationComplete()
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()
at mx.core::UIComponent/set initialized()
at mx.managers::LayoutManager/doPhasedInstantiation()
at mx.managers::LayoutManager/doPhasedInstantiationCallback()
And here is snippet of the init() function:
protected var text1:String="Text to be typed"; //hard-coded temporarily
protected const TIMER_INTERVAL:int = 10;
protected var t:Timer = new Timer(TIMER_INTERVAL);
protected var topURL:String=ExternalInterface.call('top.location.toString');
protected function init():void
{
t.addEventListener(TimerEvent.TIMER, updateTimer);
ProblemText.text = new String(text1);
Facebook.init("<my app id>",loginHandler);
currentState = (topURL) ? "loggedout": "loggedoutonfacebook";
}
Some notes:
1.my app id is my facebook app id which I prefer not to show
2.ProblemText is a richtext which I placed the paragraph to be typed by the player.
3.I have deleted the method Application1_creationComplete() but it still appears at the error listing
And also I am curious about the errors other than the first two. What do they mean?
Ah, and if it is helpful, I can post some more of the code
First: You're only seeing one error. Everything you see below the #1009 error is your stack trace, not additional errors.
The stack trace basically tells you the series of things that happened prior to the error occurring, with the most recent at the top. This is useful because often things which happen prior to the actual error you see will contribute to said error.
Second: The null object reference is occurring because something in your init() function tried to access a property in an object that doesn't exist, or an object that doesn't exist. One (slightly messy but effective) way to debug this would be to drop some trace statements in the code to see how far it gets before barfing with the error -- the idea being to isolate the specific line that's causing the problem. Once you've done that, you need to work backwards to figure out why the object or property you're trying to use is null. It could be something simple, like a typo, or it could be more complex. You'll have to sleuth it out, one way or another =)
Good luck!
Finally got the bug. Just in case people have the same case with me, what exactly happened is at my computer I simulated the game with just one state, but when I'm deploying to facebook I have several states (loggedin,loggedout,etc). In the init() I tried to access ProblemText Label that is not present in the current state.
In my AIR application (with mate-Framework) i did follwing things:
click on a button
call a method in my model "onApplicationBusy"
apply some filter in arraycollections.
In my onApplicationBusy there is this code:
FlexGlobals.topLevelApplication.enabled = false;
FlexGlobals.topLevelApplication.
I trace every step and all methods are called in right order.
But my application never becomes disabled.
Why. Is there a method for this purpose.
I try InvalidateDisplayList or ValidateNow or callLater. But all tries won't work. Probably i try it on the wrong place?
I assume, my application is so busy while applying filters (4 values for 10.000 lines) that the disabled property can't processed.
If i call the method without applying the filters all works fine.
If i call just the disbaled property but never enable the app again, the app will shown as disabled after applying the filters. for me too late.
What i origin want is a clear behavior, when the app is busy and when not (ready for clicking on buttons and all this stuff).
If you can help me or know a method, how can i shown a busy application, please help me
Thanks
Frank
All right, the setTimeout Method solve my issue. I assume, I have to wait for the next screen refresh.
Why callLater won't work and when i have to implement those functions, because i have too less ressources while my filterFunction is running?
Frank
I'm using FlexGlobals.topLevelApplication.stage.mouseChildren = false | true;
Worth noting that I first tried setting the mouseEnabled flag but found various visual elements would not update at all while mouseEnabled = false.