Deallocated NSMutableArray? - xcode

Question

I can't work out what I am doing wrong with an NSMustableArray. It is fair to say that I don't really understand memory allocation that well, so I apologize if this is a simple questions.
I have a tab bar application that is working well, and on one of the tab bars I have a front view and a back view of a person.
In the .h I have
#interface BurnsCalculatorViewController : UIViewController// <UIPickerViewDelegate, UIPickerViewDataSource>
{
UIView *frontView;
UIView *backView;
UIButton *frontButton;
UIButton *backButton;
NSMutableArray *frontBurnsArray;
}
#property (nonatomic, retain) UIView *frontView;
#property (nonatomic, retain) UIView *backView;
#property (nonatomic, retain) UIButton *frontButton;
#property (nonatomic, retain) UIButton *backButton;
#property (nonatomic, retain) NSMutableArray *frontBurnsArray;
-(IBAction)frontButtonSelect:(id)sender;
-(IBAction)backButtonSelect:(id)sender;
#end
Then I have the .m file
#implementation BurnsCalculatorViewController
#synthesize frontView;
#synthesize backView;
#synthesize frontButton;
#synthesize backButton;
#synthesize frontBurnsArray;
-(IBAction)frontButtonSelect:(id)sender
{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.0];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:[self view] cache:YES];
[self.view addSubview:backView];
[self.view addSubview:backButton];
[UIView commitAnimations];
NSLog(#"%#", frontBurnsArray);
}
-(IBAction)backButtonSelect:(id)sender
{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.0];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:[self view] cache:YES];
[self.view addSubview:frontView];
[self.view addSubview:frontButton];
[UIView commitAnimations];
NSLog(#"%#", frontBurnsArray);
}
-(void)viewDidLoad
{
frontBurnsArray = [NSMutableArray arrayWithObjects: #"frontHead", #"frontChest", #"frontAbdomen", #"frontGroin",#"frontLeftArm", #"frontLeftForeArm", #"frontRightArm", #"frontRightForearm", #"frontLeftThigh", #"frontLeftLowerLeg", #"frontRightThigh", #"frontRightLowerLeg",nil];
CGRect viewframe = CGRectMake(0, 0, 320, 480);
frontView = [[UIView alloc] initWithFrame:viewframe];
frontView.backgroundColor = [UIColor blueColor];
[self.view addSubview:frontView];
frontButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[frontButton addTarget:self action:#selector(frontButtonSelect:) forControlEvents:UIControlEventTouchDown];
[frontButton setTitle:#"Show Back" forState:UIControlStateNormal];
frontButton.frame = CGRectMake(210, 10, 100, 30);
[self.view addSubview:frontButton];
backView = [[UIView alloc] initWithFrame:viewframe];
backView.backgroundColor = [UIColor blackColor];
backButton = [[UIButton buttonWithType:UIButtonTypeRoundedRect] retain];
[backButton addTarget:self action:#selector(backButtonSelect:)forControlEvents:UIControlEventTouchDown];
[backButton setTitle:#"Show Front" forState:UIControlStateNormal];
backButton.frame = CGRectMake(210, 10, 100, 30);
}
-(void)dealloc
{
[super dealloc];
[frontButton release];
[backButton release];
[frontBurnsArray release];
}
#end
What I can't figure out is why the NSLogs in the IBActions are both telling me that the instance has been deallocated. Apart from the "release" in the dealloc, I am have said to retain the array and have not released it elsewhere.
I have spent ages searching for an answer to this, but just can't figure it out.
Thanks!!

Answer 1

frontBurnsArray = [NSMutableArray arrayWithObjects: #"frontHead", #"frontChest", #"frontAbdomen", #"frontGroin",#"frontLeftArm", #"frontLeftForeArm", #"frontRightArm", #"frontRightForearm", #"frontLeftThigh", #"frontLeftLowerLeg", #"frontRightThigh", #"frontRightLowerLeg",nil];
You are not using the retaining property
try
self.frontBurnsArray = [NSMutableArray arrayWithObjects: #"frontHead",
#"frontChest",
#"frontAbdomen",
//....
nil];
You are creating an array, that is autorealesed, meaning it will disappear on the next run-loop. If you assign it to the property, it get automatically retained and will exists until you release it. you also could call
frontBurnsArray = [[NSMutableArray arrayWithObjects: #"frontHead",
#"frontChest",
#"frontAbdomen",
//....
nil] retain];