一个很好的图表制作第三方框架的使用：Charts

创建折线图 lineChartView，创建如下图的效果

折线图

• 初始化折线图，并进行配置

let lineChartView = LineChartView().then {
        
        $0.noDataText = "暂无统计数据"
        $0.chartDescription?.enabled = false //是否显示描述
        $0.drawGridBackgroundEnabled = true
        
        let xAxisFormatter = NumberFormatter()
        xAxisFormatter.minimumFractionDigits = 0
        xAxisFormatter.maximumFractionDigits = 1
        xAxisFormatter.negativePrefix = "月"
        xAxisFormatter.positiveSuffix = "月"
        
        //chart设置,x轴设置
        let xAxis = $0.xAxis
        xAxis.labelPosition = .bottom //x轴的位置
        xAxis.labelFont = .systemFont(ofSize: 10)
        xAxis.drawGridLinesEnabled = false
        xAxis.granularity = 1.0
        //        xAxis.labelCount = 12
        xAxis.valueFormatter = DefaultAxisValueFormatter(formatter: xAxisFormatter)
        
        $0.leftAxis.drawGridLinesEnabled = false //左侧y轴设置，不画线
        $0.leftAxis.axisMinimum = 0.0 //最小数据
        $0.rightAxis.drawGridLinesEnabled = false //右侧y轴设置，不画线
        $0.rightAxis.axisMinimum = 0.0
        
        $0.legend.enabled = true //下方的说明
        let legend = $0.legend
        legend.horizontalAlignment = .left
        legend.verticalAlignment = .bottom
        legend.orientation = .horizontal
        legend.drawInside = false
        legend.form = .square
        legend.formSize = 9.0
        legend.font = .systemFont(ofSize: 10)
        legend.xEntrySpace = 4.0
    }

• 添加到视图

self.view.addSubview(self.lineChartView)
self.lineChartView.snp.makeConstraints {
            $0.centerX.equalToSuperview()
            $0.width.height.equalTo(screeW-20)
            $0.top.equalTo(self.segcontrol.snp.bottom).offset(10)
        }
self.setLineChartViewData(withModel: self.model)

• 设置折线图的数据

/// 设置折线图的数据
    ///
    /// - Parameter model: 数据
    func setLineChartViewData(withModel model: ChartModels) {
        
        let charArray = model.chatDatas
        
        var dataEntris = [ChartDataEntry]()
        for chart in charArray {
            
            let dataEntry = ChartDataEntry(x: Double(chart.month), y: Double(chart.count))
            dataEntris.append(dataEntry)
        }
        
        let set = LineChartDataSet(values: dataEntris, label: "发布数/月份")
        set.drawIconsEnabled = true
        //虚线
        //            set.lineDashLengths = [5.0, 2.5]
        //            set.highlightLineDashLengths = [5.0, 2.5]
        set.setColor(NavbarColor)
        set.setCircleColor(.black)
        set.lineWidth = 1.0
        set.circleRadius = 3.0
        
        //legend 的一些设置，标记大小，字体等，在初始化的时候进行了设置
//        set.valueFont = .systemFont(ofSize: 10)
//        set.formLineDashLengths = [5.0, 2.5]
//        set.formLineWidth = 1.0
//        set.formSize = 15.0
        
        //填充色
//        let gradientColors = [ChartColorTemplates.colorFromString("#00ff0000").cgColor, NavbarColor.cgColor]
//        let gradient = CGGradient(colorsSpace: nil, colors: gradientColors as CFArray, locations: nil)
//        
//        set.fillAlpha = 1.0
//        set.fill = Fill.fillWithLinearGradient(gradient!, angle: 90)
        set.drawFilledEnabled = false
        //            CGGradientRelease(gradient);
        
        let data = LineChartData(dataSet: set)
        self.lineChartView.data = data
        
        self.lineChartView.animate(xAxisDuration: 1.0, yAxisDuration: 1.0, easingOption: .easeInBack)
    }