ios - 不明白如何修复线程 1 : ECX_BAD_ACCESS (code = EXC_I386_GPFLT) (line chart swift iOS)

Question

我正在尝试制作一个没有库的折线图，但我只是 cmd+c、cmd+v 所有代码。是的，我知道我不应该这样做，但我没有太多时间

所以我在这个的帮助下做了一切 - https://medium.com/@tstenerson/lets-make-a-line-chart-in-swift-3-5e819e6c1a00

还在 View Controller 中添加了一个 View ，并将其命名为 LineChart

但在第 42 行我收到错误 Thread 1: ECX_BAD_ACCESS (code = EXC_I386_GPFLT)

lineChart.deltaX = 20

不知道怎么解决

我只在 ViewController.swift 中编码，如下:

import UIKit

extension String {
    func size(withSystemFontSize pointSize: CGFloat) -> CGSize {
        return (self as NSString).size(attributes: [NSFontAttributeName: UIFont.systemFont(ofSize: pointSize)])
    }
}

extension CGPoint {
    func adding(x: CGFloat) -> CGPoint { return CGPoint(x: self.x + x, y: self.y) }
    func adding(y: CGFloat) -> CGPoint { return CGPoint(x: self.x, y: self.y + y) }
}

class ViewController: UIViewController {

    @IBOutlet var lineChart: LineChart!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let f: (CGFloat) -> CGPoint = {
            let noiseY = (CGFloat(arc4random_uniform(2)) * 2 - 1) * CGFloat(arc4random_uniform(4))
            let noiseX = (CGFloat(arc4random_uniform(2)) * 2 - 1) * CGFloat(arc4random_uniform(4))
            let b: CGFloat = 5
            let y = 2 * $0 + b + noiseY
            return CGPoint(x: $0 + noiseX, y: y)
        }

        let xs = [Int](1..<20)

        let points = xs.map({f(CGFloat($0 * 10))})

        lineChart.deltaX = 20
        lineChart.deltaY = 30

        lineChart.plot(points)

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    class LineChart: UIView {

        let lineLayer = CAShapeLayer()
        let circlesLayer = CAShapeLayer()

        var chartTransform: CGAffineTransform?

        @IBInspectable var lineColor: UIColor = UIColor.green {
            didSet {
                lineLayer.strokeColor = lineColor.cgColor
            }
        }

        @IBInspectable var lineWidth: CGFloat = 1

        @IBInspectable var showPoints: Bool = true { // show the circles on each data point
            didSet {
                circlesLayer.isHidden = !showPoints
            }
        }

        @IBInspectable var circleColor: UIColor = UIColor.green {
            didSet {
                circlesLayer.fillColor = circleColor.cgColor
            }
        }

        @IBInspectable var circleSizeMultiplier: CGFloat = 3

        @IBInspectable var axisColor: UIColor = UIColor.white
        @IBInspectable var showInnerLines: Bool = true
        @IBInspectable var labelFontSize: CGFloat = 10

        var axisLineWidth: CGFloat = 1
        var deltaX: CGFloat = 10 // The change between each tick on the x axis
        var deltaY: CGFloat = 10 // and y axis
        var xMax: CGFloat = 100
        var yMax: CGFloat = 100
        var xMin: CGFloat = 0
        var yMin: CGFloat = 0

        var data: [CGPoint]?

        override init(frame: CGRect) {
            super.init(frame: frame)
            combinedInit()
        }

        required init?(coder aDecoder: NSCoder) {
            super.init(coder: aDecoder)
            combinedInit()
        }

        func combinedInit() {
            layer.addSublayer(lineLayer)
            lineLayer.fillColor = UIColor.clear.cgColor
            lineLayer.strokeColor = lineColor.cgColor

            layer.addSublayer(circlesLayer)
            circlesLayer.fillColor = circleColor.cgColor

            layer.borderWidth = 1
            layer.borderColor = axisColor.cgColor
        }


        override func layoutSubviews() {
            super.layoutSubviews()
            lineLayer.frame = bounds
            circlesLayer.frame = bounds

            if let d = data{
                setTransform(minX: xMin, maxX: xMax, minY: yMin, maxY: yMax)
                plot(d)
            }
        }

        func setAxisRange(forPoints points: [CGPoint]) {
            guard !points.isEmpty else { return }

            let xs = points.map() { $0.x }
            let ys = points.map() { $0.y }


            // МИНИМАЛЬНЫЕ И МАКСИМАЛЬНЫЕ ЗНАЧЕНИЯ
            xMax = ceil(xs.max()! / deltaX) * deltaX
            yMax = ceil(ys.max()! / deltaY) * deltaY
            xMin = 0
            yMin = 0
            setTransform(minX: xMin, maxX: xMax, minY: yMin, maxY: yMax)
        }

        func setAxisRange(xMin: CGFloat, xMax: CGFloat, yMin: CGFloat, yMax: CGFloat) {
            self.xMin = xMin
            self.xMax = xMax
            self.yMin = yMin
            self.yMax = yMax

            setTransform(minX: xMin, maxX: xMax, minY: yMin, maxY: yMax)
        }

        func setTransform(minX: CGFloat, maxX: CGFloat, minY: CGFloat, maxY: CGFloat) {

            let xLabelSize = "\(Int(maxX))".size(withSystemFontSize: labelFontSize)

            let yLabelSize = "\(Int(maxY))".size(withSystemFontSize: labelFontSize)

            let xOffset = xLabelSize.height + 2
            let yOffset = yLabelSize.width + 5

            let xScale = (bounds.width - yOffset - xLabelSize.width/2 - 2)/(maxX - minX)
            let yScale = (bounds.height - xOffset - yLabelSize.height/2 - 2)/(maxY - minY)

            chartTransform = CGAffineTransform(a: xScale, b: 0, c: 0, d: -yScale, tx: yOffset, ty: bounds.height - xOffset)

            setNeedsDisplay()  
        }

        override func draw(_ rect: CGRect) {
            // draw rect comes with a drawing context, so lets grab it.
            // Also, if there is not yet a chart transform, we will bail on performing any other drawing.
            // I like guard statements for this because it's kind of like a bouncer to a bar.
            // If you don't have your transform yet, you can't enter drawAxes.
            guard let context = UIGraphicsGetCurrentContext(), let t = chartTransform else { return }
            drawAxes(in: context, usingTransform: t)
        }

        func drawAxes(in context: CGContext, usingTransform t: CGAffineTransform) {
            context.saveGState()

            // Make two paths, one for thick lines, one for thin.
            let thickerLines = CGMutablePath()
            let thinnerLines = CGMutablePath()

            // The two line chart axes.
            let xAxisPoints = [CGPoint(x: xMin, y: 0), CGPoint(x: xMax, y: 0)]
            let yAxisPoints = [CGPoint(x: 0, y: yMin), CGPoint(x: 0, y: yMax)]

            // Add each to thicker lines but apply our transform too.
            thickerLines.addLines(between: xAxisPoints, transform: t)
            thickerLines.addLines(between: yAxisPoints, transform: t)

            // Next we go from xMin to xMax by deltaX using stride
            for x in stride(from: xMin, through: xMax, by: deltaX) {

                // Tick points are the points for the ticks on each axis.
                // We check showInnerLines first to see if we are drawing small ticks or full lines.
                // Yip for new guys: `let a = someBool ? b : c`  is called a ternary operator.
                // In English it means "let a = b if somebool is true, or c if it is false."

                let tickPoints = showInnerLines ?
                    [CGPoint(x: x, y: yMin).applying(t), CGPoint(x: x, y: yMax).applying(t)] :
                    [CGPoint(x: x, y: 0).applying(t), CGPoint(x: x, y: 0).applying(t).adding(y: -5)]


                thinnerLines.addLines(between: tickPoints)

                if x != xMin {  // draw the tick label (it is too buy if you draw it at the origin for both x & y
                    let label = "\(Int(x))" as NSString // Int to get rid of the decimal, NSString to draw
                    let labelSize = "\(Int(x))".size(withSystemFontSize: labelFontSize)
                    let labelDrawPoint = CGPoint(x: x, y: 0).applying(t)
                        .adding(x: -labelSize.width/2)
                        .adding(y: 1)

                    label.draw(at: labelDrawPoint,
                               withAttributes:
                        [NSFontAttributeName: UIFont.systemFont(ofSize: labelFontSize),
                         NSForegroundColorAttributeName: axisColor])
                }
            }
            // Repeat for y.
            for y in stride(from: yMin, through: yMax, by: deltaY) {

                let tickPoints = showInnerLines ?
                    [CGPoint(x: xMin, y: y).applying(t), CGPoint(x: xMax, y: y).applying(t)] :
                    [CGPoint(x: 0, y: y).applying(t), CGPoint(x: 0, y: y).applying(t).adding(x: 5)]


                thinnerLines.addLines(between: tickPoints)

                if y != yMin {
                    let label = "\(Int(y))" as NSString
                    let labelSize = "\(Int(y))".size(withSystemFontSize: labelFontSize)
                    let labelDrawPoint = CGPoint(x: 0, y: y).applying(t)
                        .adding(x: -labelSize.width - 1)
                        .adding(y: -labelSize.height/2)

                    label.draw(at: labelDrawPoint,
                               withAttributes:
                        [NSFontAttributeName: UIFont.systemFont(ofSize: labelFontSize),
                         NSForegroundColorAttributeName: axisColor])
                }
            }
            // Finally set stroke color & line width then stroke thick lines, repeat for thin.
            context.setStrokeColor(axisColor.cgColor)
            context.setLineWidth(axisLineWidth)
            context.addPath(thickerLines)
            context.strokePath()

            context.setStrokeColor(axisColor.withAlphaComponent(0.5).cgColor)
            context.setLineWidth(axisLineWidth/2)
            context.addPath(thinnerLines)
            context.strokePath()

            context.restoreGState()
            // Whenever you change a graphics context you should save it prior and restore it after.
            // If we were using a context other than draw(rect) we would have to also end the graphics context.
        }

        func plot(_ points: [CGPoint]) {
            lineLayer.path = nil
            circlesLayer.path = nil
            data = nil

            guard !points.isEmpty else { return }

            self.data = points

            if self.chartTransform == nil {
                setAxisRange(forPoints: points)
            }

            let linePath = CGMutablePath()
            linePath.addLines(between: points, transform: chartTransform!)

            lineLayer.path = linePath

            if showPoints {
                circlesLayer.path = circles(atPoints: points, withTransform: chartTransform!)
            }
        }

        func circles(atPoints points: [CGPoint], withTransform t: CGAffineTransform) -> CGPath {

            let path = CGMutablePath()
            let radius = lineLayer.lineWidth * circleSizeMultiplier/2
            for i in points {
                let p = i.applying(t)
                let rect = CGRect(x: p.x - radius, y: p.y - radius, width: radius * 2, height: radius * 2)
                path.addEllipse(in: rect)

            }

            return path
        }
    } // <- I didn't close the LineChart class up top, closing it now

    }

Answer 1

在 Storyboard 中删除指向“lineChart”的引用 socket 链接并尝试以下操作:

import UIKit

extension String {
    func size(withSystemFontSize pointSize: CGFloat) -> CGSize {
        return (self as NSString).size(attributes: [NSFontAttributeName: UIFont.systemFont(ofSize: pointSize)])
    }
}

extension CGPoint {
    func adding(x: CGFloat) -> CGPoint { return CGPoint(x: self.x + x, y: self.y) }
    func adding(y: CGFloat) -> CGPoint { return CGPoint(x: self.x, y: self.y + y) }
}

class ViewController: UIViewController {

//    @IBOutlet var lineChart: LineChart! ////////////REMOVED THIS
    var lineChart = LineChart(frame: CGRect.zero) ////////////ADDED THIS

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let f: (CGFloat) -> CGPoint = {
            let noiseY = (CGFloat(arc4random_uniform(2)) * 2 - 1) * CGFloat(arc4random_uniform(4))
            let noiseX = (CGFloat(arc4random_uniform(2)) * 2 - 1) * CGFloat(arc4random_uniform(4))
            let b: CGFloat = 5
            let y = 2 * $0 + b + noiseY
            return CGPoint(x: $0 + noiseX, y: y)
        }

        let xs = [Int](1..<20)

        let points = xs.map({f(CGFloat($0 * 10))})

        ////////////ADDED THIS
        self.lineChart.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height)
        self.view.addSubview(self.lineChart)

        lineChart.deltaX = 20
        lineChart.deltaY = 30

        lineChart.plot(points)

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    class LineChart: UIView {

        let lineLayer = CAShapeLayer()
        let circlesLayer = CAShapeLayer()

        var chartTransform: CGAffineTransform?

        @IBInspectable var lineColor: UIColor = UIColor.green {
            didSet {
                lineLayer.strokeColor = lineColor.cgColor
            }
        }

        @IBInspectable var lineWidth: CGFloat = 1

        @IBInspectable var showPoints: Bool = true { // show the circles on each data point
            didSet {
                circlesLayer.isHidden = !showPoints
            }
        }

        @IBInspectable var circleColor: UIColor = UIColor.green {
            didSet {
                circlesLayer.fillColor = circleColor.cgColor
            }
        }

        @IBInspectable var circleSizeMultiplier: CGFloat = 3

        @IBInspectable var axisColor: UIColor = UIColor.white
        @IBInspectable var showInnerLines: Bool = true
        @IBInspectable var labelFontSize: CGFloat = 10

        var axisLineWidth: CGFloat = 1
        var deltaX: CGFloat = 10 // The change between each tick on the x axis
        var deltaY: CGFloat = 10 // and y axis
        var xMax: CGFloat = 100
        var yMax: CGFloat = 100
        var xMin: CGFloat = 0
        var yMin: CGFloat = 0

        var data: [CGPoint]?

        override init(frame: CGRect) {
            super.init(frame: frame)
            combinedInit()
        }

        required init?(coder aDecoder: NSCoder) {
            super.init(coder: aDecoder)
            combinedInit()
        }

        func combinedInit() {
            layer.addSublayer(lineLayer)
            lineLayer.fillColor = UIColor.clear.cgColor
            lineLayer.strokeColor = lineColor.cgColor

            layer.addSublayer(circlesLayer)
            circlesLayer.fillColor = circleColor.cgColor

            layer.borderWidth = 1
            layer.borderColor = axisColor.cgColor
        }


        override func layoutSubviews() {
            super.layoutSubviews()
            lineLayer.frame = bounds
            circlesLayer.frame = bounds

            if let d = data{
                setTransform(minX: xMin, maxX: xMax, minY: yMin, maxY: yMax)
                plot(d)
            }
        }

        func setAxisRange(forPoints points: [CGPoint]) {
            guard !points.isEmpty else { return }

            let xs = points.map() { $0.x }
            let ys = points.map() { $0.y }


            // МИНИМАЛЬНЫЕ И МАКСИМАЛЬНЫЕ ЗНАЧЕНИЯ
            xMax = ceil(xs.max()! / deltaX) * deltaX
            yMax = ceil(ys.max()! / deltaY) * deltaY
            xMin = 0
            yMin = 0
            setTransform(minX: xMin, maxX: xMax, minY: yMin, maxY: yMax)
        }

        func setAxisRange(xMin: CGFloat, xMax: CGFloat, yMin: CGFloat, yMax: CGFloat) {
            self.xMin = xMin
            self.xMax = xMax
            self.yMin = yMin
            self.yMax = yMax

            setTransform(minX: xMin, maxX: xMax, minY: yMin, maxY: yMax)
        }

        func setTransform(minX: CGFloat, maxX: CGFloat, minY: CGFloat, maxY: CGFloat) {

            let xLabelSize = "\(Int(maxX))".size(withSystemFontSize: labelFontSize)

            let yLabelSize = "\(Int(maxY))".size(withSystemFontSize: labelFontSize)

            let xOffset = xLabelSize.height + 2
            let yOffset = yLabelSize.width + 5

            let xScale = (bounds.width - yOffset - xLabelSize.width/2 - 2)/(maxX - minX)
            let yScale = (bounds.height - xOffset - yLabelSize.height/2 - 2)/(maxY - minY)

            chartTransform = CGAffineTransform(a: xScale, b: 0, c: 0, d: -yScale, tx: yOffset, ty: bounds.height - xOffset)

            setNeedsDisplay()
        }

        override func draw(_ rect: CGRect) {
            // draw rect comes with a drawing context, so lets grab it.
            // Also, if there is not yet a chart transform, we will bail on performing any other drawing.
            // I like guard statements for this because it's kind of like a bouncer to a bar.
            // If you don't have your transform yet, you can't enter drawAxes.
            guard let context = UIGraphicsGetCurrentContext(), let t = chartTransform else { return }
            drawAxes(in: context, usingTransform: t)
        }

        func drawAxes(in context: CGContext, usingTransform t: CGAffineTransform) {
            context.saveGState()

            // make two paths, one for thick lines, one for thin
            let thickerLines = CGMutablePath()
            let thinnerLines = CGMutablePath()

            // the two line chart axes
            let xAxisPoints = [CGPoint(x: xMin, y: 0), CGPoint(x: xMax, y: 0)]
            let yAxisPoints = [CGPoint(x: 0, y: yMin), CGPoint(x: 0, y: yMax)]

            // add each to thicker lines but apply our transform too.
            thickerLines.addLines(between: xAxisPoints, transform: t)
            thickerLines.addLines(between: yAxisPoints, transform: t)

            // next we go from xMin to xMax by deltaX using stride
            for x in stride(from: xMin, through: xMax, by: deltaX) {

                // tick points are the points for the ticks on each axis
                // we check showInnerLines first to see if we are drawing small ticks or full lines
                // tip for new guys: `let a = someBool ? b : c`  is called a ternary operator
                // in english it means "let a = b if somebool is true, or c if it is false."

                let tickPoints = showInnerLines ?
                    [CGPoint(x: x, y: yMin).applying(t), CGPoint(x: x, y: yMax).applying(t)] :
                    [CGPoint(x: x, y: 0).applying(t), CGPoint(x: x, y: 0).applying(t).adding(y: -5)]


                thinnerLines.addLines(between: tickPoints)

                if x != xMin {  // draw the tick label (it is too buy if you draw it at the origin for both x & y
                    let label = "\(Int(x))" as NSString // Int to get rid of the decimal, NSString to draw
                    let labelSize = "\(Int(x))".size(withSystemFontSize: labelFontSize)
                    let labelDrawPoint = CGPoint(x: x, y: 0).applying(t)
                        .adding(x: -labelSize.width/2)
                        .adding(y: 1)

                    label.draw(at: labelDrawPoint,
                               withAttributes:
                        [NSFontAttributeName: UIFont.systemFont(ofSize: labelFontSize),
                         NSForegroundColorAttributeName: axisColor])
                }
            }
            // repeat for y
            for y in stride(from: yMin, through: yMax, by: deltaY) {

                let tickPoints = showInnerLines ?
                    [CGPoint(x: xMin, y: y).applying(t), CGPoint(x: xMax, y: y).applying(t)] :
                    [CGPoint(x: 0, y: y).applying(t), CGPoint(x: 0, y: y).applying(t).adding(x: 5)]


                thinnerLines.addLines(between: tickPoints)

                if y != yMin {
                    let label = "\(Int(y))" as NSString
                    let labelSize = "\(Int(y))".size(withSystemFontSize: labelFontSize)
                    let labelDrawPoint = CGPoint(x: 0, y: y).applying(t)
                        .adding(x: -labelSize.width - 1)
                        .adding(y: -labelSize.height/2)

                    label.draw(at: labelDrawPoint,
                               withAttributes:
                        [NSFontAttributeName: UIFont.systemFont(ofSize: labelFontSize),
                         NSForegroundColorAttributeName: axisColor])
                }
            }
            // finally set stroke color & line width then stroke thick lines, repeat for thin
            context.setStrokeColor(axisColor.cgColor)
            context.setLineWidth(axisLineWidth)
            context.addPath(thickerLines)
            context.strokePath()

            context.setStrokeColor(axisColor.withAlphaComponent(0.5).cgColor)
            context.setLineWidth(axisLineWidth/2)
            context.addPath(thinnerLines)
            context.strokePath()

            context.restoreGState()
            // whenever you change a graphics context you should save it prior and restore it after
            // if we were using a context other than draw(rect) we would have to also end the graphics context
        }

        func plot(_ points: [CGPoint]) {
            lineLayer.path = nil
            circlesLayer.path = nil
            data = nil

            guard !points.isEmpty else { return }

            self.data = points

            if self.chartTransform == nil {
                setAxisRange(forPoints: points)
            }

            let linePath = CGMutablePath()
            linePath.addLines(between: points, transform: chartTransform!)

            lineLayer.path = linePath

            if showPoints {
                circlesLayer.path = circles(atPoints: points, withTransform: chartTransform!)
            }
        }

        func circles(atPoints points: [CGPoint], withTransform t: CGAffineTransform) -> CGPath {

            let path = CGMutablePath()
            let radius = lineLayer.lineWidth * circleSizeMultiplier/2
            for i in points {
                let p = i.applying(t)
                let rect = CGRect(x: p.x - radius, y: p.y - radius, width: radius * 2, height: radius * 2)
                path.addEllipse(in: rect)

            }

            return path
        }
    } // <- I didn't close the LineChart class up top, closing it now

}