Adding UIImageView into NSArray crashing

Question

I would like to know how to add a UIImageView into an NSArray without it crashing.

Currently I am doing this.

//.h
@property (strong, nonatomic) UIImageView *transButtonImageView;
@property (strong, nonatomic) UIImage *transButtonImage;

//.m
@synthesize transButtonImageView;
@synthesize transButtonImage;

transButtonImage = [UIImage imageNamed:@"trans.png"];
[transButtonImageView setImage:transButtonImage];

 NSMutableArray *arrayOfButtonImages = [[NSMutableArray alloc] init];
[arrayOfButtonImages addObject:transButtonImageView]; // this is where the error happens

When I try to add transButtonImageView to the NSArray if I look at the value of the imageView it's set at nil, even though I have added the image?

1) You must know by now that you when posting a question about an error you need to post what the actual error is. 2) Have you verified whether `transButtonImageView` is `nil` or not? — rmaddy, Jul 22 '14 at 00:13
Well when I say error, it just crashes the only reason I caught it because I used an All Exceptions breakpoint.. and it just shows the "Thread 1: breakpoint 1.1" where its crashing. I used poor wording sorry. — HurkNburkS, Jul 22 '14 at 00:46
Did you ever create the image view? I don't see it in your code. — rdelmar, Jul 22 '14 at 00:51
Yeah, like @rdelmar said, you never initialized transButtonImageView, so you're adding "nil" to arrayOfButtonImages which should raise an NSInvalidArgumentException. — Lyndsey Scott, Jul 22 '14 at 01:17
To see the error message, you must press "Continue" several times after hitting the initial exception breakpoint. But before then you need to make note of where the exception occurred. Or [add logic to your main to dump the exception stack](http://stackoverflow.com/a/12268397/581994). — Hot Licks, Jul 22 '14 at 01:33

score 2 · Accepted Answer · edited Jul 22 '14 at 01:16

2

There is no crash log, so the error may come from any where, but the following are the possible ones:

Does the UIImageView initialise? As we know, nil is equal to the NSInteger 0, is not an object, so when nil is added into any container, there will be a crash;
Is the container initialised with capacity? We can only add or remove object from Mutable containers, it must be a NSMutableArray with capacity.
May the image is too large, which hold a high memory, cause the memory warning.

You'd better try all the above. Good luck!

edited Jul 22 '14 at 01:16

ccjmne

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answered Jul 22 '14 at 00:48

Niu Sir

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okay I am going to try using **transButtonImageView = [[UIImageView alloc] initWithImage:transButtonImage];** – HurkNburkS Jul 22 '14 at 00:52

score 0 · Answer 2 · answered Jul 22 '14 at 00:36

0

You need to use an NSMutableArray to be able to modify it. You can then use [mutableArray copy] to copy it to an NSArray.

answered Jul 22 '14 at 00:36

WillyCornbread

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whops.. it is a NSMutableArray.. I used poor naming convention for it and just assumed it was an array. I have checked and its definatly a NSMutableArray. – HurkNburkS Jul 22 '14 at 00:45
Then we need to see more code, are you sure you have alloc/init it? – WillyCornbread Jul 22 '14 at 00:47

Adding UIImageView into NSArray crashing

2 Answers2