无法转换“[UICollectionViewLayoutAttributes]”类型的值？ 到指定类型 'NSMutableArray'

Question

I have a class subclass of UICollectionViewFlowLayout and i have defined the layoutAttributesForElementsInRect method

And inside i am trying to make a NSMutable array so i can enumerate the objects.

the code for this is below

override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
    // I get the error at this line
    var attributes : NSMutableArray = super.layoutAttributesForElementsInRect(rect)
}

i cant subclass the attributes element as UICollectionViewLayoutAttributes as i would not be able to enumerate through it with a block

Answer 1

If you want an NSMutableArray why don't you use:

var attributes : NSMutableArray = NSMutableArray(array: super.layoutAttributesForElementsInRect(rect))

The code you have now expects an NSMutableArray but receives an array of UICollectionViewLayoutAttributes