Question

I has written following code and then run.
In after, When I touch uibutton, this app is terminated.

I want to know why terminated.

I doubt if autorelease?

Are there anyone who can explicitly explain

why myClass instance is released and

where myClass is released and

the way that myClass can use autorelease?

    @interface MyClass : NSObject
    - (void)testMethod;
    @end

    @implementation MyClass{
        NSMutableArray *array;
    }

    - (id)init{
        if ((self = [super init])) {
            array = [[NSMutableArray alloc] initWithCapacity:0];
        }
        return self;
    }

    - (void)dealloc {
        [array release];
        [super dealloc];
    }

    - (void)testMethod {
        NSLog(@"after init : %@", array);
    }

    @end

    @implementation ViewController {
        MyClass *myClass;
    }

    - (void)viewDidLoad
    {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.

        myClass = [[[MyClass alloc] init] autorelease];  <== cause of ternimate?

        UIButton *aButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
        [aButton addTarget:self action:@selector(testArray:) forControlEvents:UIControlEventTouchUpInside];
        aButton.frame=CGRectMake(110.0f, 129.0f, 100.0f, 57.0f);
        [aButton setTitle:@"title" forState:UIControlStateNormal & UIControlStateHighlighted & UIControlStateSelected];
        [self.view addSubview:aButton];

    }

    - (void)testArray:(id)sender {
        [myClass testMethod];
    }
@end

Answer 1

Seems that due to

myClass = [[[MyClass alloc] init] autorelease];

the instance of MyClass is already deallocated when you touch the button. Don’t be lazy – autorelease is not an ultimate ‘solve my memory management problem and make me not have to think’ solution – here you need to use just

myClass = [[MyClass alloc] init];

then release it manually when needed – probably in your ViewController class’ -dealloc method.