swift - UIColor 初始值设定项(无法找到接受 .... 的类型 'UIColor' 的初始值设定项)错误

Question

这个问题已经有答案了:

Swift UIColor initializer - compiler error only when targeting iPhone5s (2 个回答)

已关闭 8 年前。

我知道这不是一个合适的方法，但为了学习的目的，我有一个选择器控件，其中有四个组件，每个组件有 255 行，用于根据 RGB-alpha 更改“ View ”背景颜色。我知道UIColor(red: <#CGFloat#>, green: <#CGFloat#>, blue: <#CGFloat#>, alpha: <#CGFloat#>)接受四个 float 作为每种颜色的参数，但出现错误:
找不到接受类型为“(red: Float, green: Float, blue: Float, alpha: Float)”参数列表的“UIColor”类型的初始值设定项
怎么了？

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

    var newbackgroundColor = UIColor()

    var redCode: Float = 0.0
    var greenCode: Float = 0.0
    var blueCode: Float = 0.0
    var alphaCode: Float = 0.0

    if component == 0 {
        switch row {
        case 0..<256:
            redCode = Float(row/255)
            newbackgroundColor = UIColor(red: redCode, green: greenCode, blue: blueCode, alpha: alphaCode)
        default:
            break
        }

    } else if component == 1 {
        switch row {
        case 0..<256:
            greenCode = Float(row/255)
            newbackgroundColor = UIColor(red: redCode, green: greenCode, blue: blueCode, alpha: alphaCode)
        default:
            break
        }

    } else if component == 2{
        switch row {
        case 0..<256:
            blueCode = Float(row/255)
            newbackgroundColor = UIColor(red: redCode, green: greenCode, blue: blueCode, alpha: alphaCode)
        default:
            break
        }

    } else {
        switch row {
        case 0..<256:
            alphaCode = Float(row/255)
            newbackgroundColor = UIColor(red: redCode, green: greenCode, blue: blueCode, alpha: alphaCode)
        default:
            break
        }

    }

    self.view.backgroundColor = newbackgroundColor
}

Answer 1

使用CGFloat而不是Float

当您收到这样的错误时，请检查 API 文档