addSubview animation

Question

I have main UIView where I display different data. Then I put a button, which displays subview like this:

- (IBAction) buttonClicked:(id)sender
{
    UIView          


        

Answer 1

Let's do this in swift.

var redView = UIView(frame:CGRectMake(20,20,100,100))
redView.backgroundColor = UIColor.redColor
redView.alpha = 0.0
view.addSubview(redView)

UIView.animateWithDuration(0.25) { () -> Void in
    redView.alpha = 1.0
}

Adding a subview cannot be animated by simply putting it in an animateWithDuration block. And it can't be animated using hidden.