Different size collectionviewcells - ios

Question

http://postimg.org/image/6bws3catp/
As you can see on the image I need something that gives me the possibility of resizing a cell depending on the length of the text that contains.
I' ve been trying to do that with a UICollectionview but the cells have always the same size and if I try to alterate the size playing with the frame.size and location parameters the scroll gets crazy.
Maybe the UICollectionView isn't the best choice...
Thank you very much
EDIT:
Because of your answers my cells are able to change dynamically their size but the margins aren't behaving as I expected.
The margins of the cells depends always on the biggest cell of the same row
http://postimg.org/image/3scthf9rv/
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section{
return 6;
}
I have implement this to set my margin value between cells in 6 points, but maybe this only works when you have one cell in each row in a vertical collection view..
Thank you again for all your help

Answer 1

You can check out https://github.com/bryceredd/RFQuiltLayout . Looks
like something you can use for this...
you can override the following method and return a CGSize object that specifies the size you want to use for each cell. Using this method, you can actually have each cell be a different size:
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
Example:
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return CGSizeMake(100, 100);
}
Your view controller needs to be a delegate of UICollectionViewDelegateFlowLayout in order for this method to be called. So don't forget to add that delegate declaration to your view controller's .h file, such as:
#interface MyViewController () <UICollectionViewDelegateFlowLayout>

Answer 2

UICollectionView is the correct choice. You just need to customise the flow layout attributes.
Read Customizing the Flow Layout Attributes
Specifically you would need to implement Collection View Delegate method:
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
// In this method you can calculate the size of the string for each cell
UIFont *font = // font to create the text for each cell
NSString *string = // text string for each cell
CGSize size = [string sizeWithFont];
return size;
}