背景
项目做完出来的时候，我就发现了PieChartView标签重叠问题，奈何在网上没找解决办法，而Android对应的MPAndroidChart有相应的解决办法，于是照搬到iOS下。
思路
分析源码我们知道图表的绘制过程是由PieChartRenderer类控制的，所以我们需要自定义PieChartRenderer类，而PieChartRenderer是在PieChartView中引用的，于是我们也需要自定义PieChartView类：
代码
自定义HDPieChartRenderer
//
// HDPieChartRenderer.swift
//
// Created by Simon.Hua on 2021/11/16.
//
import UIKit
import Charts
import Foundation
import CoreGraphics
open class HDPieChartRenderer: PieChartRenderer{
init(withChart chart:PieChartView, animator:Animator, viewPortHandler:ViewPortHandler){
super.init(chart: chart, animator: animator, viewPortHandler: viewPortHandler)
}
private func minData(_ recordY:Array
var bigD:Array
var nearestlist:Array
var nearestlistCopy:Array
for k in 0..
bigD.append(abs(recordY[0][k] - pt1y))
nearestlist.append(recordY[0][k])
nearestlistCopy.append(recordY[1][k])
}
}
//距离最近的点，数值
var rF:Array = [CGFloat](repeating: 0, count: 2)
if bigD.count == 0 {
return rF
}
var minD = bigD[0]
rF[0] = nearestlist[0]
rF[1] = nearestlistCopy[0]
for g in 0..
minD = bigD[g]
rF[0] = nearestlist[g]
rF[1] = nearestlistCopy[g]
}
}
return rF
}
open override func drawValues(context: CGContext)
{
guard
let chart = chart,
let data = chart.data
else { return }
let center = chart.centerCircleBox
// get whole the radius
let radius = chart.radius
let rotationAngle = chart.rotationAngle
let drawAngles = chart.drawAngles
let absoluteAngles = chart.absoluteAngles
let phaseX = animator.phaseX
let phaseY = animator.phaseY
var labelRadiusOffset = radius / 10.0 * 3.0
if chart.drawHoleEnabled
{
labelRadiusOffset = (radius - (radius * chart.holeRadiusPercent)) / 2.0
}
let labelRadius = radius - labelRadiusOffset
let dataSets = data.dataSets
let yValueSum = (data as! PieChartData).yValueSum
let drawEntryLabels = chart.isDrawEntryLabelsEnabled
let usePercentValuesEnabled = chart.usePercentValuesEnabled
var angle: CGFloat = 0.0
var xIndex = 0
context.saveGState()
defer { context.restoreGState() }
for i in 0 ..< dataSets.count
{
guard let dataSet = dataSets[i] as? IPieChartDataSet else { continue }
let drawValues = dataSet.isDrawValuesEnabled
if !drawValues && !drawEntryLabels && !dataSet.isDrawIconsEnabled
{
continue
}
let iconsOffset = dataSet.iconsOffset
let xValuePosition = dataSet.xValuePosition
let yValuePosition = dataSet.yValuePosition
let valueFont = dataSet.valueFont
let entryLabelFont = dataSet.entryLabelFont ?? chart.entryLabelFont
let lineHeight = valueFont.lineHeight
let textHeight = entryLabelFont?.lineHeight
guard let formatter = dataSet.valueFormatter else { continue }
var leftRecordY = [[CGFloat]](repeating: [CGFloat](repeating: 0, count: dataSet.entryCount), count: 2)
var rightRecordY = [[CGFloat]](repeating: [CGFloat](repeating: 0, count: dataSet.entryCount), count: 2)
for j in 0 ..< dataSet.entryCount
{
guard let e = dataSet.entryForIndex(j) else { continue }
let pe = e as? PieChartDataEntry
if xIndex == 0
{
angle = 0.0
}
else
{
angle = absoluteAngles[xIndex - 1] * CGFloat(phaseX)
}
let sliceAngle = drawAngles[xIndex]
let sliceSpace = getSliceSpace(dataSet: dataSet)
let sliceSpaceMiddleAngle = sliceSpace / (labelRadius * .pi / 180)
// offset needed to center the drawn text in the slice
let angleOffset = (sliceAngle - sliceSpaceMiddleAngle / 2.0) / 2.0
angle = angle + angleOffset
let transformedAngle = rotationAngle + angle * CGFloat(phaseY)
let value = usePercentValuesEnabled ? e.y / yValueSum * 100.0 : e.y
let valueText = formatter.stringForValue(
value,
entry: e,
dataSetIndex: i,
viewPortHandler: viewPortHandler)
let sliceXBase = cos(transformedAngle * .pi / 180)
let sliceYBase = sin(transformedAngle * .pi / 180)
let drawXOutside = drawEntryLabels && xValuePosition == .outsideSlice
let drawYOutside = drawValues && yValuePosition == .outsideSlice
let drawXInside = drawEntryLabels && xValuePosition == .insideSlice
let drawYInside = drawValues && yValuePosition == .insideSlice
let valueTextColor = dataSet.valueTextColorAt(j)
let entryLabelColor = dataSet.entryLabelColor ?? chart.entryLabelColor
if drawXOutside || drawYOutside
{
let valueLineLength1 = dataSet.valueLinePart1Length
let valueLineLength2 = dataSet.valueLinePart2Length
let valueLinePart1OffsetPercentage = dataSet.valueLinePart1OffsetPercentage
var pt2: CGPoint
var labelPoint: CGPoint
var align: NSTextAlignment
var line1Radius: CGFloat
if chart.drawHoleEnabled
{
line1Radius = (radius - (radius * chart.holeRadiusPercent)) * valueLinePart1OffsetPercentage + (radius * chart.holeRadiusPercent)
}
else
{
line1Radius = radius * valueLinePart1OffsetPercentage
}
let polyline2Length = dataSet.valueLineVariableLength
? labelRadius * valueLineLength2 * abs(sin(transformedAngle * .pi / 180))
: labelRadius * valueLineLength2
let pt0 = CGPoint(
x: line1Radius * sliceXBase + center.x,
y: line1Radius * sliceYBase + center.y)
var pt1 = CGPoint(
x: labelRadius * (1 + valueLineLength1) * sliceXBase + center.x,
y: labelRadius * (1 + valueLineLength1) * sliceYBase + center.y)
if transformedAngle.truncatingRemainder(dividingBy: 360.0) >= 90.0 && transformedAngle.truncatingRemainder(dividingBy: 360.0) <= 270.0
{
let nearestPoint = minData(leftRecordY, pt1y: pt1.y)
leftRecordY[0][j] = pt1.y
//判断是否需要挪位置
if (nearestPoint[0] != 0) && (abs(nearestPoint[0] - pt1.y) < (textHeight! + lineHeight)) {
pt1 = CGPoint(x: pt1.x, y: nearestPoint[1] - textHeight!)
}
pt2 = CGPoint(x: pt1.x - polyline2Length, y: pt1.y)
align = .right
labelPoint = CGPoint(x: pt2.x - 5, y: pt2.y - textHeight!)
leftRecordY[1][j] = pt1.y
}
else
{
let nearestPoint = minData(rightRecordY, pt1y: pt1.y)
rightRecordY[0][j] = pt1.y
//判断是否需要挪位置
if (nearestPoint[0] != 0) && (abs(nearestPoint[0] - pt1.y) < (textHeight! + lineHeight)){
pt1 = CGPoint(x: pt1.x, y: nearestPoint[1] + textHeight!)
}
pt2 = CGPoint(x: pt1.x + polyline2Length, y: pt1.y)
align = .left
labelPoint = CGPoint(x: pt2.x + 5, y: pt2.y - textHeight!)
rightRecordY[1][j] = pt1.y
}
DrawLine: do
{
if dataSet.useValueColorForLine
{
context.setStrokeColor(dataSet.color(atIndex: j).cgColor)
}
else if let valueLineColor = dataSet.valueLineColor
{
context.setStrokeColor(valueLineColor.cgColor)
}
else
{
return
}
context.setLineWidth(dataSet.valueLineWidth)
context.move(to: CGPoint(x: pt0.x, y: pt0.y))
context.addLine(to: CGPoint(x: pt1.x, y: pt1.y))
context.addLine(to: CGPoint(x: pt2.x, y: pt2.y))
context.drawPath(using: CGPathDrawingMode.stroke)
}
if drawXOutside && drawYOutside
{
ChartUtils.drawText(
context: context,
text: valueText,
point: labelPoint,
align: align,
attributes: [NSAttributedString.Key.font: valueFont, NSAttributedString.Key.foregroundColor: valueTextColor]
)
if j < data.entryCount && pe?.label != nil
{
ChartUtils.drawText(
context: context,
text: pe!.label!,
point: CGPoint(x: labelPoint.x, y: labelPoint.y + lineHeight),
align: align,
attributes: [
NSAttributedString.Key.font: entryLabelFont ?? valueFont,
NSAttributedString.Key.foregroundColor: entryLabelColor ?? valueTextColor]
)
}
}
else if drawXOutside
{
if j < data.entryCount && pe?.label != nil
{
ChartUtils.drawText(
context: context,
text: pe!.label!,
point: CGPoint(x: labelPoint.x, y: labelPoint.y + lineHeight / 2.0),
align: align,
attributes: [
NSAttributedString.Key.font: entryLabelFont ?? valueFont,
NSAttributedString.Key.foregroundColor: entryLabelColor ?? valueTextColor]
)
}
}
else if drawYOutside
{
ChartUtils.drawText(
context: context,
text: valueText,
point: CGPoint(x: labelPoint.x, y: labelPoint.y + lineHeight / 2.0),
align: align,
attributes: [NSAttributedString.Key.font: valueFont, NSAttributedString.Key.foregroundColor: valueTextColor]
)
}
}
if drawXInside || drawYInside
{
// calculate the text position
let x = labelRadius * sliceXBase + center.x
let y = labelRadius * sliceYBase + center.y - lineHeight
if drawXInside && drawYInside
{
ChartUtils.drawText(
context: context,
text: valueText,
point: CGPoint(x: x, y: y),
align: .center,
attributes: [NSAttributedString.Key.font: valueFont, NSAttributedString.Key.foregroundColor: valueTextColor]
)
if j < data.entryCount && pe?.label != nil
{
ChartUtils.drawText(
context: context,
text: pe!.label!,
point: CGPoint(x: x, y: y + lineHeight),
align: .center,
attributes: [
NSAttributedString.Key.font: entryLabelFont ?? valueFont,
NSAttributedString.Key.foregroundColor: entryLabelColor ?? valueTextColor]
)
}
}
else if drawXInside
{
if j < data.entryCount && pe?.label != nil
{
ChartUtils.drawText(
context: context,
text: pe!.label!,
point: CGPoint(x: x, y: y + lineHeight / 2.0),
align: .center,
attributes: [
NSAttributedString.Key.font: entryLabelFont ?? valueFont,
NSAttributedString.Key.foregroundColor: entryLabelColor ?? valueTextColor]
)
}
}
else if drawYInside
{
ChartUtils.drawText(
context: context,
text: valueText,
point: CGPoint(x: x, y: y + lineHeight / 2.0),
align: .center,
attributes: [NSAttributedString.Key.font: valueFont, NSAttributedString.Key.foregroundColor: valueTextColor]
)
}
}
if let icon = e.icon, dataSet.isDrawIconsEnabled
{
// calculate the icon's position
let x = (labelRadius + iconsOffset.y) * sliceXBase + center.x
var y = (labelRadius + iconsOffset.y) * sliceYBase + center.y
y += iconsOffset.x
ChartUtils.drawImage(context: context,
image: icon,
x: x,
y: y,
size: icon.size)
}
xIndex += 1
}
}
}
}
自定义HDPieChartView
//
// HDPieChartView.swift
//
// Created by Simon.Hua on 2021/11/16.
//
import UIKit
open class HDPieChartView: PieChartView {
public override init(frame: CGRect)
{
super.init(frame: frame)
renderer = HDPieChartRenderer.init(withChart: self, animator: self.chartAnimator, viewPortHandler: self.viewPortHandler)
}
required public init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
方法调用
只需要将原来初始化的地方，类名换成HDPieChartView就行了
if (!pieChartView) {
pieChartView = [[HDPieChartView alloc] initWithFrame:superView.bounds];
}