如何在Swift3 IOS饼图中添加点击手势识别？

Question

我正在使用Swift 3开发小型IOS应用程序。在那个应用程序里，我想有一个饼图。为了构建饼图，我遵循了这个链接，饼图正在生成。

现在我想再添加一个功能。当用户像任何月份一样点击饼图的某个区域时，它应该打开一个新的控制器并仅显示该月份的详细信息。

我设法添加了手势识别功能。但是当我点击屏幕的任何部分时，它会打开新屏幕。我想限制该抽头功能仅为饼图部分，饼图月份应被捕获。代码是

let gestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.handleTap))

pieChartView.addGestureRecognizer(gestureRecognizer)

和处理点击代码是

func handleTap(gestureRecognizer: UIGestureRecognizer) {
let monthDetail = storyboard?.instantiateViewController(withIdentifier: "MonthTableView") as! MonthDetailsTableViewController
monthDetail = month  //Should be the month value of Tap area
navigationController?.pushViewController(monthDetail, animated: true)

}

感谢任何帮助！！

==========================

import UIKit
import Charts
import CoreData

class ExpenseViewController: UIViewController, ChartViewDelegate {

@IBOutlet weak var pieChartView: PieChartView!

    let months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun"]
    var unitsSold = [10.0, 20.0, 10.0, 30.0, 10.0, 10.0]

     override func viewDidLoad() {
        super.viewDidLoad()

        setChart(dataPoints: months, values: unitsSold)

        pieChartView.delegate = self
     }

     func setChart(dataPoints: [String], values: [Double]) {
        var dataEntries: [ChartDataEntry] = []

        for i in 0..<dataPoints.count {
            let dataEntry = PieChartDataEntry(value: values[i], label: dataPoints[i])
            dataEntries.append(dataEntry)
        }


        let pieChartDataSet = PieChartDataSet(values: dataEntries, label: "Units Sold")
        let pieChartData = PieChartData(dataSet: pieChartDataSet)

        pieChartView.data = pieChartData

      }

     func chartValueSelected(chartView: ChartViewBase, entry: ChartDataEntry, dataSetIndex: Int, highlight: ChartHighlighter) {
        //print("\(entry.value) in \(months[entry.xIndex])")
        print("Y = \(entry.y) ")
        print("X = \(entry.x) ")
    }

}

Answer 1

在handleTap中，使用手势识别器的locationInView来找出点击在图表的哪个部分（如果有的话），并做出相应的响应。

Answer 2

检查Appcoda教程中的触摸事件部分，您会发现ChartViewDelegate方法chartValueSelected，因此您需要使用该方法而不是UITapgestureRecognitizer。

func chartValueSelected(_ chartView: ChartViewBase, entry: ChartDataEntry, highlight: Highlight) {
     print("\(entry.value) in \(yourArray[entry.xIndex])")
}