ios-charts缺少PieChart的标签(传说)

这是我的代码 –

// This is the delegate method for creaTing data for chart
        func offDaysDidLoaded(controller: DataModel,chartArray:[PFObject]) {


                let formatter = NSDateFormatter()
                formatter.dateFormat = "MMM"
                dataDict = [:]
                for od in chartArray {
                    let date = od["Date"] as! NSDate
                    let month = formatter.StringFromDate(datE)
                    if self.dateDict.indexForKey(month) != nil {
                        self.dateDict[month]! += 1.0
                    }else{
                        self.dateDict.updateValue(1.0,forKey: month)
                    }
                }
                let dataPointArray = Array(dateDict.keys)
                let valuesArray = Array(dateDict.values)
                pieChartView.data = nil
                pieChartView.BACkgroundColor = UIColor.grayColor()
                setChart(dataPointArray,values: valuesArray)
            }


func setChart(dataPoints: [String],values: [Double]) {
    var dataEntries: [ChartDataEntry] = []
    for i in 0..<dataPoints.count {

        let dataEntry = ChartDataEntry(value: values[i],xIndex: i)
        dataEntries.append(dataEntry)
    }

    let pieChartDataSet = PieChartDataSet(yVals: dataEntries,label: "Months")

    let pieChartData = PieChartData(xVals: dataPoints,dataSet: pieChartDataSet)
    pieChartData.setDrawValues(false)
    pieChartView.data = pieChartData
    pieChartView.animate(xAxisDuration: NSTimeInterval(5))

    var colors: [UIColor] = []

    for _ in 0..<dataPoints.count {
        let red = Double(arc4random_uniform(256))
        let green = Double(arc4random_uniform(256))
        let blue = Double(arc4random_uniform(256))

        let color = UIColor(red: CGFloat(red/255),green: CGFloat(green/255),blue: CGFloat(blue/255),alpha: 1)
        colors.append(color)
    }

    pieChartDataSet.colors = colors

}

我在here中看到了类似的问题并且构建和运行,问题中使用的饼图也没有在图表下方显示任何图例.任何帮助或指针将非常感激.

谢谢