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  • 如何使用 SwiftChars 库指定条形图中条形之间的最小间距？

    • 这是我使用 SwiftCharts 显示条形图的代码示例：
    // xAxis

 let labelSettings = ChartLabelSettings(font: .systemFont(ofSize: 13.0), fontColor: .aiduBlue)

 var xValues = [ChartAxisValue]()
 xValues.append(ChartAxisValueString(order: -1))
 for (index, point) in barsDataSource.enumerated() {
     let dateString = DateFormatter.shortDayOfWeekDayOnTwoLinesFormatter.string(from: point.departureDate)
     xValues.append(ChartAxisValueString(dateString, order: index, labelSettings: labelSettings))
 }
 xValues.append(ChartAxisValueString(order: xValues.count - 1))
 let xModel = ChartAxisModel(axisValues: xValues,
                             lineColor: .aiduSkyBlue,
                             axisTitleLabel: ChartAxisLabel(text: "", settings: labelSettings))

 // yAxis

 let yAxisMinSpaceBetweenPoints: CGFloat = 10.0
 let yAxisTopBottomMargin = (((barsMaxPrice - barsMinPrice) / Double(barsDataSource.count)) + Double(yAxisMinSpaceBetweenPoints)) + 10
 let yAxisGenerator = ChartAxisValuesGeneratorNice(minValue: barsMinPrice - yAxisTopBottomMargin,
                                                   maxValue: barsMaxPrice + yAxisTopBottomMargin,
                                                   preferredDividers: 1,
                                                   minSpace: yAxisMinSpaceBetweenPoints,
                                                   maxTextSize: CGFloat.greatestFiniteMagnitude,
                                                   multiplierUpdateMode: .nice)
 let yLabelsGenerator = ChartAxisLabelsGeneratorFunc {scalar in
     return ChartAxisLabel(text: "", settings: ChartLabelSettings())
 }
 let yModel = ChartAxisModel(lineColor: UIColor.white.withAlphaComponent(0),
                             firstModelValue: barsMinPrice,
                             lastModelValue: barsMaxPrice,
                             axisTitleLabels: [],
                             axisValuesGenerator: yAxisGenerator,
                             labelsGenerator: yLabelsGenerator)

 // Char Bars layer

 let frame = chartFrame(containerView.bounds)
 let coordsSpace = ChartCoordsSpaceLeftBottomSingleAxis(chartSettings: chartSettings,
                                                        chartFrame: frame,
                                                        xModel: xModel,
                                                        yModel: yModel)
 let (xAxisLayer, yAxisLayer, innerFrame) = (coordsSpace.xAxisLayer, coordsSpace.yAxisLayer, coordsSpace.chartInnerFrame)

 let barsModels: [ChartBarModel] = barsDataSource.enumerated().flatMap { index, item in
     [
         ChartBarModel(constant: ChartAxisValueInt(index),
                       axisValue1: ChartAxisValueDouble(0),
                       axisValue2: ChartAxisValueDouble(item.price),
                       bgColor: barColor(price: item.price, minPrice: barsMinPrice))
     ]
 }

 let chartBarSettings = ChartBarViewSettings(animDuration: 0,
                                             animDelay: 0,
                                             cornerRadius: 0,
                                             roundedCorners: .allCorners,
                                             selectionViewUpdater: nil,
                                             delayInit: false)

 let chartBarsLayer =  ChartBarsLayer(xAxis: xAxisLayer.axis,
                                      yAxis: yAxisLayer.axis,
                                      bars: barsModels,
                                      horizontal: false,
                                      barWidth: 40,
                                      settings: chartBarSettings,
                                      mode: .translate,
                                      tapHandler: { [weak self] (tappedBar) in
                                         self?.chartBarTapHandler(tappedBar: tappedBar)
     }, viewGenerator: { [weak self] (p1, p2, barWidth, color, settings, model, index) -> ChartPointViewBar in
         var barBGColor = color
         if let s = self, let lastTappedBarModel = s.lastTappedBarModel {
             let currentBarModel = s.dataSource[index]
             barBGColor = currentBarModel.departureDate == lastTappedBarModel.departureDate && currentBarModel.duration == lastTappedBarModel.duration ? s.barSelectionBgColor : color
         }
         let view = ChartPointViewBar(p1: p1, p2: p2, width: barWidth, bgColor: barBGColor, settings: settings)
         return view
 })

 // Price labels layer

 let labelToBarSpace: Double = 20
 let labelChartPoints = barsModels.map { bar in
     ChartPoint(x: bar.constant, y: bar.axisValue2.copy(bar.axisValue2.scalar + labelToBarSpace))
 }

 let priceLabelsLayer = ChartPointsViewsLayer(xAxis: xAxisLayer.axis,
                                              yAxis: yAxisLayer.axis,
                                              chartPoints: labelChartPoints,
                                              viewGenerator: {(chartPointModel, layer, chart) -> UIView? in
                                                 let label = HandlingLabel()
                                                 label.text = PriceFormatter.string(fromPrice: Float(chartPointModel.chartPoint.y.scalar - labelToBarSpace))
                                                 label.font = .boldSystemFont(ofSize: 10.0)
                                                 label.textColor = UIColor.aiduBlue
                                                 label.sizeToFit()
                                                 let pos = chartPointModel.chartPoint.y.scalar > 0
                                                 label.center = CGPoint(x: chartPointModel.screenLoc.x, y: pos ? innerFrame.origin.y : innerFrame.origin.y + innerFrame.size.height)
                                                 label.alpha = 0
                                                 label.isUserInteractionEnabled = false
                                                 label.movedToSuperViewHandler = {[weak label] in
                                                     label?.alpha = 1
                                                     label?.center.y = chartPointModel.screenLoc.y
                                                 }
                                                 return label
 }, displayDelay: 0, mode: .translate)

 return Chart(
     frame: frame,
     innerFrame: innerFrame,
     settings: chartSettings,
     layers: [
         xAxisLayer,
         yAxisLayer,
         chartBarsLayer,
         priceLabelsLayer
     ]
 )

private var chartSettings: ChartSettings {
     var chartSettings = ChartSettings()
     chartSettings.leading = 2
     chartSettings.top = 2
     chartSettings.trailing = 2
     chartSettings.bottom = 2
     chartSettings.axisStrokeWidth = 0.4
     chartSettings.spacingBetweenAxesX = 2
     chartSettings.spacingBetweenAxesY = 2
     chartSettings.labelsSpacing = 10
     chartSettings.labelsToAxisSpacingY = 0
     chartSettings.spacingBetweenAxesY = 0
     chartSettings.axisTitleLabelsToLabelsSpacing = 0
     chartSettings.zoomPan.panEnabled = true
     chartSettings.zoomPan.zoomEnabled = false
     chartSettings.zoomPan.maxZoomX = 3
     chartSettings.zoomPan.minZoomX = 3
     chartSettings.zoomPan.minZoomY = 1
     chartSettings.zoomPan.maxZoomY = 1
     return chartSettings
 }

    • 当数据源包含大约（前 10 个）点时，如果您更改（增加/减少）数据源，则图表不会重叠，但条形之间没有固定空间： 不重叠

    • 当数据源包含大约（前 35 个）点时，条形重叠： 重叠

SwiftCharts 版本 0.6.5 Swift 版本 5

4

1 回答 1

1

最后我找到了解决方案：

我必须将 minZoomX 和 maxZoomX（在图表设置中）设置为固定值，即图表的页数（或可滚动区域的数量比原始宽度）。为什么 x ？因为我希望图表水平滚动。

这是代码：

        let barWidth: CGFloat = 30.0
        let spaceBetweenBars: CGFloat = 80.0

        let zoomXValue = CGFloat(barsDataSource.count) / (UIScreen.main.bounds.width / (barWidth + spaceBetweenBars))
        chartSettings.zoomPan.minZoomX = zoomXValue
        chartSettings.zoomPan.maxZoomX = zoomXValue
于 2019-09-16T10:20:38.617 回答