根据单元格不改变单元格高度动态地更改UICollectionView高度

Question

I am developing IOS App.Click to Tableview cell Than value show on collectionViewCell but I want change collectionView height according to cell's.

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    return CGSizeMake(_collectionView.frame.size.width , _collectionView.frame.size.height+30);

}

Answer 1

you can change it by using contentSize of its scrollView after the collectionview is loaded.. if you update any cell insert items or delete items you need to update height again ie

myCollectionView.reload()

now updating frame or height

//if you are using auto-resizing you can update frame
let frame = myCollectionView.frame
frame.height = myCollectionView.contentSize.height
myCollectionView.frame = frame

and if you are using autolayout make and iboutlet for your collectionview's height constraint

@IBOutlet collectionViewHeightConstraint:NSLayoutContraint!

now update this contraint

collectionViewHeightConstraint.constant = myCollectionView.contentSize.height

Answer 2

You need to add this code

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize
{
    var numberOfCellInRow : Int = yourArray.count
    var padding : Int = 5
    var collectionCellWidth : CGFloat = (self.view.frame.size.width/CGFloat(numberOfCellInRow)) - CGFloat(padding)
    return CGSize(width: collectionCellWidth , height: collectionCellWidth)
}