Question

有没有一种方法可以生成一个UIColor到UIColor范围内的red表（或者说green的数组），使得变量{{1 }}将具有相应的颜色var match = 100，而green将具有相应的颜色var match = 0，并且中间变量值接近red时，它们之间的变量值将变得更绿色？

感谢您的帮助。

Answer 1

这是一个有用的UIColor扩展名，可让您根据百分比在两种颜色之间进行混合。

extension UIColor {
    // This function calculates a new color by blending the two colors.
    // A percent of 0.0 gives the "self" color
    // A percent of 1.0 gives the "to" color
    // Any other percent gives an appropriate color in between the two
    func blend(to: UIColor, percent: Double) -> UIColor {
        var fR : CGFloat = 0.0
        var fG : CGFloat = 0.0
        var fB : CGFloat = 0.0
        var tR : CGFloat = 0.0
        var tG : CGFloat = 0.0
        var tB : CGFloat = 0.0

        getRed(&fR, green: &fG, blue: &fB, alpha: nil)
        to.getRed(&tR, green: &tG, blue: &tB, alpha: nil)

        let dR = tR - fR
        let dG = tG - fG
        let dB = tB - fB

        let perc = min(1.0, max(0.0, percent))
        let rR = fR + dR * CGFloat(perc)
        let rG = fG + dG * CGFloat(perc)
        let rB = fB + dB * CGFloat(perc)

        return UIColor(red: rR, green: rG, blue: rB, alpha: 1.0)
    }
}

示例：

let red = UIColor.red.blend(to: .green, percent: 0)
let mix = UIColor.red.blend(to: .green, percent: 0.5)
let green = UIColor.red.blend(to: .green, percent: 1)

iOS（Swift）：将缩放值表示为UIColor

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