ios - 如何使用研究工具包构建饼图

您好，我是 swift 新手，我尝试使用研究工具包应用构建饼图。

我引用这个 link 写了一些代码

运行我的代码时，它显示错误“类型'ViewController'不符合协议(protocol)'ORK PieChartView DataSource'”

请建议如何解决这个问题。

这是我的代码:

import UIKit
    import ResearchKit

    class ViewController: UIViewController,ORKPieChartViewDataSource {


        @IBOutlet weak var pieChartView: ORKPieChartView!
        var colors : NSArray!

        override func viewDidLoad() {
            super.viewDidLoad()

                colors = [
                UIColor(red: 217/225, green: 217/255, blue: 217/225, alpha: 1),
                UIColor(red: 142/255, green: 142/255, blue: 147/255, alpha: 1),
                UIColor(red: 244/255, green: 200/255, blue: 74/255, alpha: 1)
            ]

            // Connect the pie chart object to a data source
            pieChartView.dataSource = pieChartDataSource

            // Optional custom configuration
            pieChartView.showsTitleAboveChart = false
            pieChartView.showsPercentageLabels = true
            pieChartView.drawsClockwise = true
            pieChartView.titleColor = UIColor.purple
            pieChartView.textColor = UIColor.purple
            pieChartView.title = "Weekly"
            pieChartView.text = "Report"
            pieChartView.lineWidth = 10
            pieChartView.showsPercentageLabels = true

        }

        override func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
            // Dispose of any resources that can be recreated.
        }

        func numberOfSegmentsInPieChartView(pieChartView: ORKPieChartView ) -> Int {
            return 3
        }

        func pieChartView(_ pieChartView: ORKPieChartView, valueForSegmentAt index: Int) -> CGFloat {
            switch index {
            case 0:
                return 60.0
            case 1:
                return 25.0
            case 2:
                return 15.0
            }

            // Optional methods
            // Give a color to each segment in the pie chart.
            func pieChartView(pieChartView: ORKPieChartView, colorForSegmentAtIndex index: Int) -> UIColor {
                return colors[index]
            }

            // Give a title to each segment in the pie chart.
            func pieChartView(pieChartView: ORKPieChartView, titleForSegmentAtIndex index: Int) -> String {
                switch index {
                case 0:
                    return "Steps taken"
                case 1:
                    return "Tasks completed"
                case 2:
                    return "Surveys completed"
                default:
                    return "task \(index + 1)"
                }
            }
        }
    }

---

Best Answer-推荐答案

The error 'Type 'ViewController' does not conform to protocol 'ORK PieChartView DataSource' means that you are not implemented all the required data source methods..... Here in your code you wrote a wrong datasource method as func pieChartView(_ pieChartView: ORKPieChartView, valueForSegmentAt index: Int) -> CGFloat, change it like below.....

func pieChartView(pieChartView: ORKPieChartView, valueForSegmentAt index: Int) -> CGFloat {
                switch index {
                case 0:
                    return 60.0
                case 1:
                    return 25.0
                case 2:
                    return 15.0
                }

关于ios - 如何使用研究工具包构建饼图，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45053763/