饼图使用图表库与iOSswift3

我想在Github上使用piechart danielgindi/Charts库.我的代码是这样的:

import UIKit
import Charts

class ChartViewController: UIViewController {

    @IBOutlet weak var pieChartView: PieChartView!

    override func viewDidLoad() {
        super.viewDidLoad()

    // Do any additional setup after loading the view.

        let mOnths= ["Jan", "Feb", "Mar", "Apr", "May", "Jun"]
        let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0]

        setChart(dataPoints: months, values: unitsSold)

    }


    func setChart(dataPoints: [String], values: [Double]) {

        var dataEntries: [ChartDataEntry] = []

        for i in 0..

但是当我运行它时,请分解这一行:

pieChartView.data = pieChartData


我没有在任何图表库之前使用,但是我必须使用一个项目.这个图书馆或其他图书馆对我来说无关紧要.如果您知道回答我的问题,请帮助我解决.或者您可以告诉我另一个与switf 3兼容的库.谢谢.


1> KrishnaCA..：
我以pieChartView编程方式初始化并将其添加到子视图中.代码运行正常,不会崩溃.我做了必要的更改并在下面添加了它:

import UIKit
import Charts

class ChartViewController: UIViewController {

   var pieChartView: PieChartView!

   override func viewDidLoad() {
       super.viewDidLoad()

       // Do any additional setup after loading the view.

       let mOnths= ["Jan", "Feb", "Mar", "Apr", "May", "Jun"]
       let unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0]

       pieChartView = PieChartView(frame: self.view.bounds)
       self.view.addSubview(pieChartView!)
       setChart(dataPoints: months, values: unitsSold)
   }

   func setChart(dataPoints: [String], values: [Double]) {

       var dataEntries: [ChartDataEntry] = []

       for i in 0..