ios - 如何自定义条形图值？ (图表框架)

Question

我正在使用图表框架的BarChartView..我想自定义值(1699,2181..)我的应用程序中出现的图形如下。

我想自定义值，如下图所示。

如何在值上添加背景颜色、圆角半径和边框？

部分代码如下

let chartDataSet = BarChartDataSet(values: dataEntries, label: "")
chartDataSet.colors = [UIColor.gray, UIColor.lightGray]
chartDataSet.drawValuesEnabled = true // Values
let myFont: NSUIFont = UIFont(name: "SFProDisplay-Semibold", size: 12.0)!
chartDataSet.valueFont = myFont

chart.xAxis.valueFormatter = IndexAxisValueFormatter(values: avgValue)
chart.xAxis.labelPosition = .bottom

chart.drawGridBackgroundEnabled = false
chart.xAxis.granularity = 1
chart.animate(xAxisDuration: 1.0, yAxisDuration: 1.0)
chart.leftAxis.axisMinimum = 0    
chart.rightAxis.enabled = false

chart.extraRightOffset = 20
chart.extraLeftOffset = 20
chart.extraBottomOffset = 10
chart.extraTopOffset = 10

chart.legend.enabled = false

let chartData = BarChartData()
chartData.addDataSet(chartDataSet)
chart.data = chartData

Answer 1

使用 BalloonMarker 获得此类设计。创建名为 BallonMarker 的新类。

open class BalloonMarker: MarkerImage {

    open var color: UIColor
    open var arrowSize = CGSize(width: 15, height: 11)
    open var font: UIFont
    open var textColor: UIColor
    open var insets: UIEdgeInsets
    open var minimumSize = CGSize()
    open var chartWidth = CGFloat()

    fileprivate var label: String?
    fileprivate var _labelSize: CGSize = CGSize()
    fileprivate var _paragraphStyle: NSMutableParagraphStyle?
    fileprivate var _drawAttributes = [NSAttributedStringKey : AnyObject]()

    public init(color: UIColor, font: UIFont, textColor: UIColor, insets: UIEdgeInsets) {
        self.color = color
        self.font = font
        self.textColor = textColor
        self.insets = insets

        _paragraphStyle = NSParagraphStyle.default.mutableCopy() as? NSMutableParagraphStyle
        _paragraphStyle?.alignment = .center
        _paragraphStyle?.lineBreakMode = .byWordWrapping
        super.init()
    }

    open override func offsetForDrawing(atPoint point: CGPoint) -> CGPoint {
        var offset = self.offset
        var size = self.size

        if size.width == 0.0 && image != nil {
            size.width = image!.size.width
        }
        if size.height == 0.0 && image != nil {
            size.height = image!.size.height
        }

        let width = size.width
        let height = size.height
        let padding: CGFloat = 8.0

        var origin = point
        origin.x -= width / 2
        origin.y -= height

        if origin.x + offset.x < 0.0 {
            offset.x = -origin.x + padding
        }
        else if let chart = chartView,
            origin.x + width + offset.x > chart.bounds.size.width
        {
            offset.x = chart.bounds.size.width - origin.x - width - padding
        }

        if origin.y + offset.y < 0 {
            offset.y = height + padding;
        }
        else if let chart = chartView,
            origin.y + height + offset.y > chart.bounds.size.height
        {
            offset.y = chart.bounds.size.height - origin.y - height - padding
        }

        return offset
    }

    open override func draw(context: CGContext, point: CGPoint) {
        guard let label = label else { return }

        let offset = self.offsetForDrawing(atPoint: point)
        let size = self.size

        var rect = CGRect(
            origin: CGPoint(
                x: point.x + offset.x,
                y: point.y + offset.y),
            size: size)
        rect.origin.x -= size.width / 2.0
        rect.origin.y -= size.height

        context.saveGState()

        context.setFillColor(color.cgColor)

        if offset.y > 0 {
            context.beginPath()
            context.move(to: CGPoint(
                x: rect.origin.x,
                y: rect.origin.y + arrowSize.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x + (rect.size.width - arrowSize.width) / 2.0,
                y: rect.origin.y + arrowSize.height))
            //arrow vertex
            context.addLine(to: CGPoint(
                x: point.x,
                y: point.y))
            context.addLine(to: CGPoint(
                x: rect.origin.x + (rect.size.width + arrowSize.width) / 2.0,
                y: rect.origin.y + arrowSize.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x + rect.size.width,
                y: rect.origin.y + arrowSize.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x + rect.size.width,
                y: rect.origin.y + rect.size.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x,
                y: rect.origin.y + rect.size.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x,
                y: rect.origin.y + arrowSize.height))
            context.fillPath()
        }
        else
        {
            context.beginPath()
            context.move(to: CGPoint(
                x: rect.origin.x,
                y: rect.origin.y))
            context.addLine(to: CGPoint(
                x: rect.origin.x + rect.size.width,
                y: rect.origin.y))
            context.addLine(to: CGPoint(
                x: rect.origin.x + rect.size.width,
                y: rect.origin.y + rect.size.height - arrowSize.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x + (rect.size.width + arrowSize.width) / 2.0,
                y: rect.origin.y + rect.size.height - arrowSize.height))
            //arrow vertex
            context.addLine(to: CGPoint(
                x: point.x,
                y: point.y))
            context.addLine(to: CGPoint(
                x: rect.origin.x + (rect.size.width - arrowSize.width) / 2.0,
                y: rect.origin.y + rect.size.height - arrowSize.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x,
                y: rect.origin.y + rect.size.height - arrowSize.height))
            context.addLine(to: CGPoint(
                x: rect.origin.x,
                y: rect.origin.y))
            context.fillPath()
        }

        if offset.y > 0 {
            rect.origin.y += self.insets.top + arrowSize.height
        } else {
            rect.origin.y += self.insets.top
        }

        rect.size.height -= self.insets.top + self.insets.bottom

        UIGraphicsPushContext(context)
        label.draw(in: rect, withAttributes: drawAttributes)
        UIGraphicsPopContext()
        context.restoreGState()
    }

    open override func refreshContent(entry: ChartDataEntry, highlight: Highlight) {
        setLabel(String(entry.y))
    }

    open func setLabel(_ newLabel: String) {
        label = newLabel

        _drawAttributes.removeAll()
        _drawAttributes[.font] = self.font
        _drawAttributes[.paragraphStyle] = _paragraphStyle
        _drawAttributes[.foregroundColor] = self.textColor

        _labelSize = label?.size(withAttributes: _drawAttributes) ?? CGSize.zero

        var size = CGSize()
        size.width = _labelSize.width + self.insets.left + self.insets.right
        size.height = _labelSize.height + self.insets.top + self.insets.bottom
        size.width = max(minimumSize.width, size.width)
        size.height = max(minimumSize.height, size.height)
        self.size = size
    }
}

如何将值传递给 BallonMarker。

let marker:BalloonMarker = BalloonMarker(color: UIColor.white, font: UIFont(name: "Helvetica", size: 12)!, textColor: .black, insets: UIEdgeInsets(top: 7.0, left: 7.0, bottom: 7.0, right: 7.0))
    marker.minimumSize = CGSize(width: 75.0, height: 50.0)
    chart?.marker = marker