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Answer 1

+1 A:

I've been hitting messages like this as well, and it's usually because the program is trying to access some memory location that has been released already.

Make sure your userView setPerson method is retaining the object (and releasing it in the dealloc).

Also, how are you creating & pushing your 2nd view controller? is it an instance variable or are you creating it each time?

Ben Scheirman 2009-06-12 13:12:08

The view controller is created on the fly; however this is not the problem as I've commented out all the navigation code, it seems to be the [personArray getObjectAtIndex] that makes it break :(

2009-06-12 17:13:39

Answer 2

+5 A:

Just going out on a limb, but did you make sure to add nil as the last element in the array when you created it?

NSMutableArray *array = [NSMutableArray arrayWithObjects: @"one", @"two", @"three", @"four", nil];

Tony Eichelberger 2009-06-12 13:13:51

Good idea, this has also tripped me up before!

Ben Scheirman 2009-06-12 13:15:52

The NSMutableArray had objects added to it using 'addObject' within a fast enumeration loop.

2009-06-12 17:14:13

Answer 3

A:

The NSMutableArray had objects added to it using 'addObject' within a fast enumeration loop.

Rich 2009-06-12 13:31:38

Answer 4

A:

Looks to me like indexPath.row is not what you think it is, and is requesting an object that is out of bounds.

Have you tried logging with something like this:

NSLog(@"personArraysize: %u, object I'm accessing: %@", [personArray count], indexPath.row);
[userView setPerson:[personArray objectAtIndex:indexPath.row]];

Aftermathew 2009-06-12 13:57:43

I have tried that!indexPath.row is whichever row I select, and personArray count is 3 - which is right.

2009-06-12 17:11:38

It's not the personArray that is throwing the msg_send exception. userView must have been deallocated. (according to the trace)

Jason Harwig 2009-06-12 17:25:07

Answer 5

+1 A:

Either person, userView, or personArray has been deallocated OR personArray is not as big as you think. You need to place breakpoints to find out which is the case.

You should follow the entire lifecycle of each object and make sure it is properly retained.

You can implement dealloc in custom classes and set breakpoints in there and make sure nothing gets deallocated that shouldn't.

Also try enabling NSZombie to see if it gets any messages.

Corey Floyd 2009-06-12 17:43:27

Answer 6

A:

Check if the objects, added to personArray are still valid and not autoreleased yet.
Check setPerson implementation, it may work with other objects, which are already autoreleased.

Valerii Hiora 2009-06-13 06:12:29

I believe this was the case.Rather than calling the setPerson method on userView, I've implemented a custom initialiser that accepts a Person object. This seems to work!Thanks for all the help everyone!

2009-06-16 06:50:32

Answer 7

A:

I got the same problem, I used NSArray (with nil at the end) but whenever I send objectAtIndex it crashes, today I found apple's core animation sample code, it uses NSArray as well, the initialization line is as follows:

names = [[NSArray arrayWithObjects:@"Item 1", @"Item 2", @"Item 3", @"Item 4", @"Item 5", nil] retain];

so I guess you should do it this way.

2009-09-17 16:48:12

Also, I wonder why it makes thing complicated, hard to understand, I was using Java for several years and did not have any of these problems.

2009-09-17 16:49:36

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