项目中用到了饼状图，在GitHub上搜索到一个比较好用的图表库Chars,里面包含了基本见过的各种图表库，这个项目的作者是danielgindi，这个项目是MPAndroidChart对应的Apple平台的版本（iOS/tvOS/OSX均支持），本文仅对饼状图进行使用，后续将陆续支持其他图表
![[Swift]使用Charts绘制饼状图_第1张图片](http://img.e-com-net.com/image/info10/93d1781d0e264767aaf072503af84c51.gif)
PieChart.gif
初始化PieChartView
var months = ["1-9", "10-19", "20-29", "30-39","40-49", "50-59", "60-69", "70以上"]
var unitsSold = [30.0, 100.0, 108.0, 60.0, 50.0, 160.0, 187.0, 60.0]
fileprivate lazy var pieChartView: PieChartView = {
let pieChartView = PieChartView()
pieChartView.backgroundColor = UIColor(r: 230, g: 253, b: 253)
//基本样式
pieChartView.delegate = self
return pieChartView
}()
override func viewDidLoad() {
super.viewDidLoad()
self.title = "pie chart"
view.addSubview(pieChartView)
pieChartView.snp.makeConstraints { (make) in
make.left.equalTo(self.view).offset(5)
make.top.equalTo(self.view).offset(64)
make.right.equalTo(self.view).offset(-5)
make.height.equalTo(300)
}
}
设置数据
func setChart(dataPoints: [String], values: [Double]) {
var dataEntries: [ChartDataEntry] = []
for i in 0..设置配置
//设置饼状图字体配置
func setPieChartDataSetConfig(pichartDataSet: PieChartDataSet){
pichartDataSet.sliceSpace = 0 //相邻区块之间的间距
pichartDataSet.selectionShift = 8 //选中区块时, 放大的半径
pichartDataSet.xValuePosition = .insideSlice //名称位置
pichartDataSet.yValuePosition = .outsideSlice //数据位置
//数据与区块之间的用于指示的折线样式
pichartDataSet.valueLinePart1OffsetPercentage = 0.85 //折线中第一段起始位置相对于区块的偏移量, 数值越大, 折线距离区块越远
pichartDataSet.valueLinePart1Length = 0.5 //折线中第一段长度占比
pichartDataSet.valueLinePart2Length = 0.4 //折线中第二段长度最大占比
pichartDataSet.valueLineWidth = 1 //折线的粗细
pichartDataSet.valueLineColor = UIColor.gray //折线颜色
}
//设置饼状图字体样式
func setPieChartDataConfig(pieChartData: PieChartData){
pieChartData.setValueFormatter(DigitValueFormatter())//设置百分比
pieChartData.setValueTextColor(UIColor.gray) //字体颜色为白色
pieChartData.setValueFont(UIFont.systemFont(ofSize: 10))//字体大小
}
//设置饼状图中心文本
func setDrawHoleState(){
///饼状图距离边缘的间隙
pieChartView.setExtraOffsets(left: 30, top: 0, right: 30, bottom: 0)
//拖拽饼状图后是否有惯性效果
pieChartView.dragDecelerationEnabled = true
//是否显示区块文本
pieChartView.drawSlicesUnderHoleEnabled = true
//是否根据所提供的数据, 将显示数据转换为百分比格式
pieChartView.usePercentValuesEnabled = true
// 设置饼状图描述
pieChartView.chartDescription?.text = "饼状年龄库图示例"
pieChartView.chartDescription?.font = UIFont.systemFont(ofSize: 10)
pieChartView.chartDescription?.textColor = UIColor.gray
// 设置饼状图图例样式
pieChartView.legend.maxSizePercent = 1 //图例在饼状图中的大小占比, 这会影响图例的宽高
pieChartView.legend.formToTextSpace = 5 //文本间隔
pieChartView.legend.font = UIFont.systemFont(ofSize: 10) //字体大小
pieChartView.legend.textColor = UIColor.gray //字体颜色
pieChartView.legend.verticalAlignment = .bottom //图例在饼状图中的位置
pieChartView.legend.form = .circle //图示样式: 方形、线条、圆形
pieChartView.legend.formSize = 12 //图示大小
pieChartView.legend.orientation = .horizontal
pieChartView.legend.horizontalAlignment = .center
// pieChartView.centerText = "平均库龄" //饼状图中心的文本
////饼状图中心的富文本文本
let attributes = [NSFontAttributeName: UIFont.boldSystemFont(ofSize: CGFloat(15.0)), NSForegroundColorAttributeName: UIColor.gray]
let centerTextAttribute = NSAttributedString(string: "平均库龄", attributes: attributes)
pieChartView.centerAttributedText = centerTextAttribute
/*
///设置饼状图中心的文本
if pieChartView.isDrawHoleEnabled {
///设置饼状图中间的空心样式
pieChartView.drawHoleEnabled = true //饼状图是否是空心
pieChartView.holeRadiusPercent = 0.5 //空心半径占比
pieChartView.holeColor = UIColor.clear //空心颜色
pieChartView.transparentCircleRadiusPercent = 0.52 //半透明空心半径占比
pieChartView.transparentCircleColor = UIColor(r: 210, g: 145, b: 165, 0.3) //半透明空心的颜色
pieChartView.drawCenterTextEnabled = true //是否显示中间文字
//普通文本
//pieChartView.centerText = "平均库龄"
//富文本
let attributes = [NSFontAttributeName: UIFont.boldSystemFont(ofSize: CGFloat(15.0)), NSForegroundColorAttributeName: UIColor.red]
let centerTextAttribute = NSAttributedString(string: "平均库龄", attributes: attributes)
pieChartView.centerAttributedText = centerTextAttribute
}
*/
pieChartView.setNeedsDisplay()
}
将对于的数值转化为百分比,
// pieChartData.setValueFormatter(DigitValueFormatter() //设置百分比
//转化为带%
class DigitValueFormatter: NSObject, IValueFormatter {
func stringForValue(_ value: Double, entry: ChartDataEntry, dataSetIndex: Int, viewPortHandler: ViewPortHandler?) -> String {
let valueWithoutDecimalPart = String(format: "%.2f%%", value)
return valueWithoutDecimalPart
}
代理方法
//MARK: -- ChartViewDelegate
//点击空白地区
func chartValueNothingSelected(_ chartView: ChartViewBase) {
}
//点击饼状图上的事件
func chartValueSelected(_ chartView: ChartViewBase, entry: ChartDataEntry, highlight: Highlight) {
let al = UIAlertController.init(title: nil, message: "点击的是：\(months[Int(highlight.x)]) 值为： \(highlight.y)", preferredStyle: .alert)
let cancel = UIAlertAction.init(title: "知道了", style: .cancel, handler: nil)
al.addAction(cancel)
self.present(al, animated: true, completion: nil)
}