How can i refresh slices? about piecharts HOT 5 CLOSED

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(true)
       
        //remove subviews
        view.subviews.forEach({ $0.removeFromSuperview() })
        
        //label view
        label.text = "\(views!) views"
        view.addSubview(label)
        
        //add chart
        chartView = PieChart(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))
        chartView.delegate = self
        chartView.models = createModels()
        chartView.layers = [createCustomViewsLayer(), createTextLayer(), createTextWithLinesLayer()]
        view.addSubview(chartView)
        chartView.setNeedsDisplay()
        
      
    }