带有渐变填充的 iOS Swift Highcharts Pie 是黑色的

Question

I am using this example to create a pie chart on iOS: https://www.highcharts.com/ios/demo/pie-gradient

The pie chart renders fine but the gradient fill is only black color. I converted the code in example to Swift like this:

let colors = [
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
            stops: [[ 0, "#7cb5ec" ],[1, "rgb(48,105,160)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#434348" ],[1, "rgb(0,0,0)"]])!,
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#90ed7d" ],[1, "rgb(68,161,49)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#f7a35c" ],[1, "rgb(171,87,16)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#8085e9" ],[1, "rgb(52,57,157)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#f15c80" ],[1, "rgb(165,16,52)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#e4d354" ],[1, "rgb(152,135,8)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#2b908f" ],[1, "rgb(0,68,67)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#f45b5b" ],[1, "rgb(168,15,15)"]]),
        HIColor(radialGradient: ["cx": 0.5, "cy": 0.3,"r": 0.7],
                stops: [[ 0, "#91e8e1" ],[1, "rgb(69,156,149)"]])
    ]

In the given example, they have assigned colors array to options.colors but it takes only String array and not HIColor array. Here's the error I am getting: error.png

In order to fix the error, here's the code modification I tried which gives black colored pie:

let colors_str = colors.map{
        (color: HIColor!) -> String  in

        let c = color.getData().debugDescription
        .replacingOccurrences(of: "Optional(", with: "")
        .replacingOccurrences(of: "\n", with: "")
        .replacingOccurrences(of: "\"", with: "")
        .dropLast()

        let value = String(c)
        return value
    } 

options.colors = colors_str

black-pie-chart

Any help will be highly appreciated.

Answer 1

I found the solution to this problem. Wanted to post it since I spent a day on it and in case someone else faces the same issue. So the code of iOS on Highcarts samples is incorrect. I referred to the Javascript code of same pie and found out that colors is assigned to plot options pie color. Here's the sample code in swift:

 let plot_options = HIPlotOptions()
 plot_options.pie = HIPie()
 plot_options.pie.colors = colors as? [HIColor]