ios - 在 Swift 中，使用选择器 init 覆盖的方法具有不兼容的类型

Question

我是 Swift 新手，我正在尝试像下面这样子类化:

public class CombinedChartRenderer: ChartDataRendererBase {

    private weak var _chart: CombinedChartView!

    public init(chart: CombinedChartView, animator: ChartAnimator, viewPortHandler: ChartViewPortHandler)
    {
        super.init(animator: animator, viewPortHandler: viewPortHandler)

        _chart = chart

        createRenderers()
    }
}

public class MyCombinedChartRenderer: CombinedChartRenderer {
    private weak var _chart: MyCombinedChartView!
    public override init(chart: MyCombinedChartView, animator: ChartAnimator, viewPortHandler: ChartViewPortHandler)
    {
        super.init(chart: chart, animator: animator, viewPortHandler: viewPortHandler)

        _chart = chart
    }
}

它总是说

使用选择器“initWithChart:animator:viewPortHandler:”的重写方法具有不兼容的类型“(MyCombinedChartView、ChartAnimator、ChartViewPortHandler) -> MyCombinedChartRenderer”

我不确定它出了什么问题。我看到其他代码可以通过提供更专门的子类来执行此类初始化。

CombinedChartView 就像:

public class CombinedChartView: BarLineChartViewBase
{
...
}

public class MyCombinedChartView: CombinedChartView
{
    // do some customization and override
}

Answer 1

只需更改一些变量名称，与 init 发生冲突并删除该覆盖关键字即可；

public class CombinedChartRenderer: ChartDataRendererBase {

    private weak var _chart: CombinedChartView!

    public init(chart: CombinedChartView, animator: ChartAnimator, viewPortHandler: ChartViewPortHandler)
    {
        super.init(animator: animator, viewPortHandler: viewPortHandler)

        _chart = chart

        createRenderers()
    }
}

public class MyCombinedChartRenderer: CombinedChartRenderer {
    private weak var _myChart: MyCombinedChartView!
    public init(myChart: MyCombinedChartView, animator: ChartAnimator, viewPortHandler: ChartViewPortHandler)
    {
        super.init(chart: myChart, animator: animator, viewPortHandler: viewPortHandler)

        _myChart = myChart // This can be removed by marking baseclass instance '_chart' as public; 
    }
}