I am parsing quite a large JSON model, and I have a LOT of objects set up to handle all the data. I recently added more data to the JSON model, to test it out, and I am getting this error
-[NSNull count]: unrecognized selector sent to instance 0xaed678
However, I need to know EXACTLY which function is crashing in order to fix it, but for some reason, xCode does not tell you where the function crashes which seems very odd, as that is very important information if you want to rectify the bug. Is there anyway for me to find out exactly which method or function caused the application to crash?
Thanks in advance
Set a breakpoint on unrecognized selector:
Creating breakpoint in Xcode for unrecognized selector
Then trace back in the code.
Related
It looks like there is a lot of way to get this error. I couldn't find any solution that worked in my case. The difference with most thread with the same error, is that the view that throw the error is my initial view and not called by a segue.
Here Is my error log:
Tabuleo[87837:3767493] -[loginViewController _setViewDelegateContentOverlayInsetsAreClean:]:
unrecognized selector sent to instance 0x7fb513d104e0
2018-07-03 13:37:25.365645+0200 Tabuleo[87837:3767493]
*** Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '-[loginViewController _setViewDelegateContentOverlayInsetsAreClean:]:
unrecognized selector sent to instance
I can't figure out by myself where it comes from because in my code I don't have any method called "_setViewDelegateContentOverlayInsetsAreClean".
At this point I don't have any clue and I read almost all post related to that.
My code is about 350 lines so I put a link to download it if it helps.
loginViewController.m
Thanks for your help.
I figured it out finally.
I don't know exactly where it was messed up but redo every link of my elements in my storyboard for this view finally ended up working !
So if that happen just redo your links from storyboard to .h file.
How do i figure out which selector is this , from this error message ?
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayM length]: unrecognized selector sent to instance 0x178059b30'
how do I make xcode give me normal error messages, ones that will tell me where the problem is exactly?
That is a normal error message. The system can't tell you more than this.
But with the help of the debugger (exception breakpoints enabled), and a good understanding of Objective-C you should be able to diagnose the problem.
Here is what we know from the exception message:
The unrecognized selector was length. The most common class that has this method is NSString.
The object that received this method was a NSArray
After the exception breakpoint was triggered type po 0x178059b30 into the debugger to inspect the array. This content of the array can give you hints to figure out how the problem was caused initially.
From the debugger position in your code you can see what triggered the bug.
You say your code failed at [_label setText:name].
This method expects a NSString, during assignment a couple of NSString specific methods are called, length is one of these methods. Which confirms point one of our guess.
There are two possibilities:
name is actually a NSArray because you wrote code that assigned the wrong object. This often happens if you don't check the results you get from a dictionary or an array.
You have a memory problem and name was deallocated prematurely and an array is now where the NSString should be.
To rule out the second option a run of the Analyzer is often enough. It will point out most memory problems.
Another way to decide which of the two is more likely you use the output of po 0x178059b30. If the array holds objects that are related to the expected value of name (e.g. it actually contains name) there is a high chance that you did assign the wrong object. In this case look where you set name, and put a check around it.
If you use a property you can use something like this to figure out where you assign the wrong object:
- (void)setName:(NSString *)name
_name = [name copy];
if (![name isKindOfClass:[NSString class]]) {
NSAssert(NO, #"Wrong class %#", name);
}
}
A breakpoint will be triggered when the assigned object is not a NSString instance, and you can inspect the call stack to see where you did something wrong.
Make sure to remove that code after you are done debugging. You MUST NOT use such checks to prevent bugs in your code.
I have the following output from my app at the moment:
2012-09-14 11:55:32.558 projectname[2172:707] -[__NSCFBoolean isEqualToString:]:
unrecognized selector sent to instance 0x3ec4ba18
2012-09-14 11:55:32.570 projectname[2172:707] *** Terminating app due to uncaught
exception 'NSInvalidArgumentException', reason: '-[__NSCFBoolean isEqualToString:]:
unrecognized selector sent to instance 0x3ec4ba18'
*** First throw call stack:
(0x3263788f 0x3468d259 0x3263aa9b 0x32639915 0x32594650 0x41e47 0x417d3 0x46af7
0x320beefb 0x320bdfd9 0x320bd763 0x32061f15 0x325961fb 0x342faaa5 0x342fa6bd
0x342fe843 0x342fe57f 0x342f64b9 0x3260bb1b 0x32609d57 0x3260a0b1 0x3258d4a5
0x3258d36d 0x316e4439 0x3208ccd5 0x17e77 0x15ca4)
terminate called throwing an exception
I can see that the problem is that I'm trying to compare a BOOL to an NSString, the comparison is on data from a web service and it's always been BOOL before now. That's besides the point in this case anyway.
What information is in that log that can actually help me find the line of code that's causing the problem? I can see which instances (e.g. 0x3ec4ba18) are causing it but the log doesn't even tell me what type they are, let alone a line number.
Add an exception breakpoint by going to the exceptions pane (in the left sidebar), clicking the + and selection "Exception breakpoint". Then when you run the debugger will pause where the exception is actually thrown rather then when it is caught (or rather uncaught) at the top level.
There are many tutorials on this, Raywinderlich has one of good tutorial for determining crash from the console log..
Here you can get them..
My App Crashed, Now What? – Part 1
My App Crashed, Now What? – Part 2
After following these, come to know the specific reason of crash then google for this, you can resolve it easily.
How do I go about finding out where in my code caused the following exception?
2012-08-15 09:24:27.414 TestProject[82870:17303] -[TestObj doIt]: unrecognized selector sent to instance 0x1106f320
Best way to do it: Add a breakpoint to capture all exceptions, that will give you the line of code where you are getting the exception. From the console, you will get the same message you are posting on your question, so, use the pointer address to print the object that is getting the exception. If the object is garbage(the debugger wont print it), that means you are overreleasing an object. If you have zombies enabled, you will find a prefix NSZombie__ on your class name. That also means overrelease. If you get a different class than the one you are expecting, you are switching the objects at some point and sending a message to the wrong object.
Go to the breakpoints navigator (on the left)
at the bottom you have a +,
add an exception breakpoint on all exceptions
set a breakpoint for thrown exceptions. by default, it will pause when an exception is thrown -- there you will see the backtrace and values.
if it's completely random (e.g. not reproducible), then you may have best luck running Instruments with zombies enabled.
I have been up and running with RestKit for ios and I feel it is great. But, I have some serious problem. I am trying to use the objectmapper in a application. While a test application with only a single view controller works fine and is able to load all the data in array. But, I try to integrate into the existing application, it always crashes with error ;
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString objectForKey:]: unrecognized selector sent to instance 0x8b55e90'
I have a core data datamodel but I have not used it for the mapping until. The code in both the test application and the existing app are same. It is annoying that the same code works fine with a single view controller while the same things does not work for integration. Any help would be much appreciated !
"unrecognized selector sent to instance" usually means that you are trying to call a method on an object that is no longer existent in memory. First you need to find out which object this is by enabling zombies in xcode.
Then you have to make sure that this object persists as long as you need it, e. g. make it a property of the parent view controller.
There was error because I was using RestKit Object loader and RestKit client to load two different urls from the same controller at the same time. And both of them would call the request delegate at first. So, the json I was expecting the requestDidLoad delegate was different as it also loaded the same delegate for objectDidLoad at first. This has been fixed now.