UIViewをフェードイン

CameraViewController.swift

    func renderView() {

        /**
         * ボタン
         */
        let buttonTake = UIButton(frame: CGRect.init(x: 0, y: 0, width: self.view.frame.size.width - 50, height: 50))
        buttonTake.backgroundColor = UIColor.init(colorLiteralRed: 0.3, green: 0.3, blue: 0.7, alpha: 0.5)
        buttonTake.alpha = 0
        buttonTake.layer.cornerRadius = 5.0
        buttonTake.layer.masksToBounds = true
        buttonTake.setTitle("ボタンです", forState: UIControlState.Normal)
        buttonTake.layer.position = CGPoint(x: self.view.bounds.width/2, y:self.view.bounds.height - 55)
        buttonTake.addTarget(self, action: "takePhoto:", forControlEvents: .TouchUpInside)
        self.view.addSubview(buttonTake)
        
        /**
         * フェードイン
         */
        UIView.animateWithDuration(0.8, delay: 1.0, options: UIViewAnimationOptions.CurveEaseInOut,
            animations: {() -> Void in
                buttonTake.alpha = 0.6
            },
            completion: {(finished: Bool) -> Void in
        })
        
    }