Release an array of uiimageviews

[juanchofern]

Hello i have an array of uiimage views in a function.

But the problem is when i call the function is sometimes i would like
to change the images, so how could i do it and releasing the memory
to avoid memory leaks.

this is my function

fullarray
{
imageBolaGris = [ImageCache loadImage:[ficherosBolasGrises objectAtIndex:i]];

tBolasGrises[i] = [[UIImageView alloc] initWithImage:imageBolaGris];
}

Thanks a lot for your help

[juanchofern]

FicherosBolasGrises is a NSMutable array of strings where i save the names
Of the images files.

In another function if i need i change the images in FicheroBolasGrises,
The problem is when i call the function to assing the images to the array
Of image views because i have not releases before, how i could release the array of image views to avoid memory leaks?
Any help?

Thanks a lot

Originally Posted by juanchofern

Hello i have an array of uiimage views in a function.

But the problem is when i call the function is sometimes i would like
to change the images, so how could i do it and releasing the memory
to avoid memory leaks.

this is my function

fullarray
{
imageBolaGris = [ImageCache loadImage:[ficherosBolasGrises objectAtIndex:i]];

tBolasGrises[i] = [[UIImageView alloc] initWithImage:imageBolaGris];
}

Thanks a lot for your help

[Duncan C]

Originally Posted by juanchofern

Hello i have an array of uiimage views in a function.

But the problem is when i call the function is sometimes i would like
to change the images, so how could i do it and releasing the memory
to avoid memory leaks.

this is my function

fullarray
{
imageBolaGris = [ImageCache loadImage:[ficherosBolasGrises objectAtIndex:i]];

tBolasGrises[i] = [[UIImageView alloc] initWithImage:imageBolaGris];
}

Thanks a lot for your help

Is tBolasGrises a C style array? The code above implies that it is.

I would advise against using a C style array to manage objects. That requires that you manage object ownership yourself.


if tBolasGrises was an NSMutableArray, your code would look like this:

UIImageView *anImageView = [[UIImageView alloc] initWithImage:imageBolaGris];
[tBolasGrises addObject: anImageView];
[anImageView release];

NSArrays and mutable arrays retain the objects that they contain. By adding anImageView to the NSMutableArray, the array becomes the owner.

The code above creates the image view using an alloc call, which returns an object you own and must release.

We pass ownership of the image view to the array, and then release the object.

After that code, only the array owns the image view. That's what you want. Then, if you later remove the object from the array, the array will release it and it will be deallocated.

If you release the array, all of the objects in the array will be released and deallocated.

Note that you usually add image views as subviews in your view hierarchy. Adding a view as a subview of another view also retains that view.

If you add an image view to an array AND add it as a subview of your view controller, it will be retained twice. To release it and free it up, you would need to both remove it from the array and remove it from it's parent view (or superview, as Cocoa touch calls it.) That's ok, but you need to make sure your code removes it from it's superview.

[juanchofern]

Ok Duncan, hello and thanks a lot. I am going to try the way you do, i have declared tBolasGrises as C style array in .h

UIImageView *tBolasGrises[91];

Thanks again for the advice.

[juanchofern]

Originally Posted by Duncan C

Is tBolasGrises a C style array? The code above implies that it is.

I would advise against using a C style array to manage objects. That requires that you manage object ownership yourself.


if tBolasGrises was an NSMutableArray, your code would look like this:

UIImageView *anImageView = [[UIImageView alloc] initWithImage:imageBolaGris];
[tBolasGrises addObject: anImageView];
[anImageView release];

NSArrays and mutable arrays retain the objects that they contain. By adding anImageView to the NSMutableArray, the array becomes the owner.

The code above creates the image view using an alloc call, which returns an object you own and must release.

We pass ownership of the image view to the array, and then release the object.

After that code, only the array owns the image view. That's what you want. Then, if you later remove the object from the array, the array will release it and it will be deallocated.

If you release the array, all of the objects in the array will be released and deallocated.

Note that you usually add image views as subviews in your view hierarchy. Adding a view as a subview of another view also retains that view.

If you add an image view to an array AND add it as a subview of your view controller, it will be retained twice. To release it and free it up, you would need to both remove it from the array and remove it from it's parent view (or superview, as Cocoa touch calls it.) That's ok, but you need to make sure your code removes it from it's superview.

Hello Duncan again,
i have created a NSMutableArray as you said me.

But now how can i acces to the properties of an UIImageView.

Before i did tBolasGrises[i].hidden=Yes.

But now i cannot do [tBolasGrises ObjectAtIndex:i].hidden=Yes
i suppose because is a array of objects.
How can i do it?

Thanks a lot for your help!!!

[apatsufas]

Yes you can't do that. You need to cast the object to an UIImageView.

(UIImageView*)[yourArray objectAtIndex:i]

[juanchofern]

Originally Posted by apatsufas

Yes you can't do that. You need to cast the object to an UIImageView.

(UIImageView*)[yourArray objectAtIndex:i]

Ok thanks a lot, but i must change a lot of code.
so i would to try with the code i have.

Do you know how can i release the array of uimageviews when i want
to change the images?

The array is Style Old C.

UIImageView tBolasGrandes[5];


this is my code

for (int i =0; i<5;i++)
{
imageBolaGrande = [ImageCache loadImage:[ficherosBolasGrandes objectAtIndex:i]];

tBolasGrandes[i] = [[UIImageView alloc] initWithImage:imageBolaGrande];
}

so in another function i would like to change ficherosbolasGrandes to assign
new images.

ficherosBolasGrandes is a NSMutableArray. This is not a problem, i can
release ficherosBolasGrandes and add new images.

Then after i would like to release tBolasGrandes to avoid memory leaks and assign the new images from ficherosBolasGrandes.

Could you help me please?

Thanks a lot, and regards.

[Duncan C]

Originally Posted by juanchofern

Ok thanks a lot, but i must change a lot of code.
so i would to try with the code i have.

Do you know how can i release the array of uimageviews when i want
to change the images?

The array is Style Old C.

UIImageView tBolasGrandes[5];


this is my code

for (int i =0; i<5;i++)
{
imageBolaGrande = [ImageCache loadImage:[ficherosBolasGrandes objectAtIndex:i]];

tBolasGrandes[i] = [[UIImageView alloc] initWithImage:imageBolaGrande];
}

so in another function i would like to change ficherosbolasGrandes to assign
new images.

ficherosBolasGrandes is a NSMutableArray. This is not a problem, i can
release ficherosBolasGrandes and add new images.

Then after i would like to release tBolasGrandes to avoid memory leaks and assign the new images from ficherosBolasGrandes.

Could you help me please?

Thanks a lot, and regards.

As the other poster said, you have to type cast an item from the array to the desired type before you can change it's properties:

((UIImageView*)[yourArray objectAtIndex:i]).hidden = TRUE;

Using a C array of objects is a lot more work, and much more prone to errors.

You need to:

Initialize the array elements to nil in your init method.

Before you store a new value into the C array, release the old value and set it to nil.

Add code in your dealloc method that loops through the C array and releases all the objects.

It gets even messier if you're using ARC, since ARC doesn't support object pointers in C arrays or structures.

[juanchofern]

Originally Posted by Duncan C

As the other poster said, you have to type cast an item from the array to the desired type before you can change it's properties:

((UIImageView*)[yourArray objectAtIndex:i]).hidden = TRUE;

Using a C array of objects is a lot more work, and much more prone to errors.

You need to:

Initialize the array elements to nil in your init method.

Before you store a new value into the C array, release the old value and set it to nil.

Add code in your dealloc method that loops through the C array and releases all the objects.

It gets even messier if you're using ARC, since ARC doesn't support object pointers in C arrays or structures.

Thanks a lot Duncan, you are very nice, ok tomorrow i ll try as you said, i will change a lot of code,

Regards!!!

[juanchofern]

Originally Posted by Duncan C

As the other poster said, you have to type cast an item from the array to the desired type before you can change it's properties:

((UIImageView*)[yourArray objectAtIndex:i]).hidden = TRUE;

Using a C array of objects is a lot more work, and much more prone to errors.

You need to:

Initialize the array elements to nil in your init method.

Before you store a new value into the C array, release the old value and set it to nil.

Add code in your dealloc method that loops through the C array and releases all the objects.

It gets even messier if you're using ARC, since ARC doesn't support object pointers in C arrays or structures.

Hello Duncan, with this question i think i finish the program

How can i do this sentence if both arrays are NSMutableArray

tUltimasCincoBolas[ContadorUltimasBolas]=tBolasPeques[bola-1];

Thanks a lot!!!

[juanchofern]

Originally Posted by juanchofern

Hello Duncan, with this question i think i finish the program

How can i do this sentence if both arrays are NSMutableArray

tUltimasCincoBolas[ContadorUltimasBolas]=tBolasPeques[bola-1];

Thanks a lot!!!

i have done it with this

[tUltimasCincoBolas replaceObjectAtIndex:ContadorUltimasBolas withObject: [tBolasPeques objectAtIndex:bola-1]];

Thanks a lot!!!!