NSMutableArray = Application Crash

[reisuke]

Hello to everybody

I am trying to create an app, and in this app I will need to hold a lot of images for a UIImageView.

Creating different variables for each image I want to load isn't hard, but it's not the right way to load many images.

So I'm trying the following:

NSMutableArray *images; //global variable in .m file

- (void)viewDidLoad {
images = [NSMutableArray arrayWithCapacity:30];
	for(NSInteger imageNum=0;imageNum<30;imageNum++)
	{
		NSString *pictureName = [[NSString alloc]initWithFormat:@"%d.png",imageNum];
		UIImage *image = [UIImage imageNamed:pictureName];
		[images addObject:image];
	}

But, even though it compiles ok without any errors or warnings, the app crashes when trying to open.

Please, someone tell me what I am doing wrong and how I can fix it.

Thank you.

(also, can someone tell me if e.g. images[5] is the right way to access an element in the array?)

[kapps11]

wats the error for the crash? because the only thing that I could think of possibly crashing with this code was if you added too many objects to the array. Maybe dont give it a specific size when you init it, just use [[NSMutableArray alloc] init]; instead. But you are leaking that NSString for the image name btw.

And in response to your uestion about accessing, NO lol. use [array objectAtIndex:]; go read the docs they explain all that stuff

[Duncan C]

Originally Posted by reisuke

Hello to everybody

I am trying to create an app, and in this app I will need to hold a lot of images for a UIImageView.

Creating different variables for each image I want to load isn't hard, but it's not the right way to load many images.

So I'm trying the following:

NSMutableArray *images; //global variable in .m file

- (void)viewDidLoad {
images = [NSMutableArray arrayWithCapacity:30];
	for(NSInteger imageNum=0;imageNum<30;imageNum++)
	{
		NSString *pictureName = [[NSString alloc]initWithFormat:@"%d.png",imageNum];
		UIImage *image = [UIImage imageNamed:pictureName];
		[images addObject:image];
	}

But, even though it compiles ok without any errors or warnings, the app crashes when trying to open.

Please, someone tell me what I am doing wrong and how I can fix it.

Thank you.

(also, can someone tell me if e.g. images[5] is the right way to access an element in the array?)

What line is it crashing on?

I'll tell you my guess. My guess is that the code you're posting works fine. It's not until later in another method when you try to USE the array that you're crashing. Why? You're not retaining the array.

You should make the array variable a retained property, and change your code to set the property using property notation, like this:

self.images = [NSMutableArray arrayWithCapacity:30];

That way, the setter for the images will retain the array and it won't get released.