Why can't I change custom view background in cell of UICollectionView - swift

Question

I have a UICollectionView and a custom UICollectionViewCell.
The UICollectionViewCell contains a custom UIView.
I need to change the color of the UIView according to a property in my array.
I have created the custom UIView in the storyboard, assigned appropriate class to it and even a tag.
I am trying to change the color of the my custom circleView in cellForItemAtIndexPath
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
var cell = collectionView.dequeueReusableCellWithReuseIdentifier("circleCell", forIndexPath: indexPath) as! BRGameCollectionViewCell
var circle = BRGameManager.sharedInstance.gameArray[indexPath.section][indexPath.row] as BRCircle!
cell.circleView.circleColor = UIColor.redColor()
return cell
}
I have tried it even with getting the circleView via tag but it doesn't work either.
What Am I doing wrong?
My custom view Class looks like this:
class BRCircleView: UIView {
var circleSize : CGFloat = 10
var circleColor : UIColor!
override init(frame: CGRect) {
if( frame == CGRectZero){
var newFrame = CGRectMake(0, 0, self.circleSize, self.circleSize)
}
self.circleColor = UIColor(rgba: GlobalConstants.colors.hexColorGreen)
super.init(frame: frame)
}
convenience init(frame: CGRect, circleColor : UIColor){
self.init(frame: frame)
self.circleColor = circleColor
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func drawRect(rect: CGRect) {
self.layer.cornerRadius = self.frame.size.width/2
self.clipsToBounds = true
self.backgroundColor = self.circleColor
}
}

Answer 1

If you want to reflect your circleView's background color change,you need to redraw your view's content.Use setNeedsDisplay method of UIView would do this trick.More about setNeedsDisplay
So before returning cell, add this line of code.
...
cell.circleView.circleColor = UIColor.redColor()
cell.circleView.setNeedsDisplay() // add this line.
return cell