convenience init(red:Int,green:Int,blue:Int,alpha:CGFloat) { var red: CGFloat = CGFloat(red)/255.0 var green: CGFloat = CGFloat(green)/255.0 var blue: CGFloat = CGFloat(blue)/255.0 self.init(red:red, green:green, blue:blue, alpha:alpha) }
我编写了上面的代码,以提供更方便的方式来声明自定义uicolor。但是以某种方式,它通过调用自身直到堆栈溢出而使我的应用程序崩溃。怎么了
另外,我只是意识到我没有明确调用此init函数。但是,UIColor.whiteColor()当发生此错误时,我正在打电话。当然,如果我显式调用此函数,仍然会发生错误!
UIColor.whiteColor()
我认为这样做不会带来任何不便:
let myCustomColorHSBa = UIColor(hue: 120/360, saturation: 0.25 , brightness: 1.0 , alpha: 1) let myCustomColorRGBa = UIColor(red: 191/255, green: 1, blue: 191/255, alpha: 1)
但是如果您真的需要一个,可以按照以下步骤操作:
extension UIColor { convenience init(red: Int = 0, green: Int = 0, blue: Int = 0, opacity: Int = 255) { precondition(0...255 ~= red && 0...255 ~= green && 0...255 ~= blue && 0...255 ~= opacity, "input range is out of range 0...255") self.init(red: CGFloat(red)/255, green: CGFloat(green)/255, blue: CGFloat(blue)/255, alpha: CGFloat(opacity)/255) } }
UIColor(red: 255) // r 1.0 g 0.0 b 0.0 a 1.0 (Red) UIColor(red: 255, green: 255) // r 1.0 g 1.0 b 0.0 a 1.0 (Yellow) UIColor(red: 255, blue: 255) // r 1.0 g 0.0 b 1.0 a 1.0 (Magenta) UIColor(green: 255) // r 0.0 g 1.0 b 0.0 a 1.0 (Green) UIColor(green: 255, blue: 255) // r 0.0 g 1.0 b 1.0 a 1.0 (Cyan) UIColor(blue: 255) // r 0.0 g 0.0 b 1.0 a 1.0 (Blue) UIColor(red: 255, green: 192, blue: 203) // r 1.0 g 0.753 b 0.796 a 1.0 (Pink) UIColor(red: 255, green: 215) // r 1.0 g 0.843 b 0.0 a 1.0 (Gold)