Xcode 9 • Swift 4 or later
extension UIColor {
convenience init?(hexaRGB: String, alpha: CGFloat = 1) {
var chars = Array(hexaRGB.hasPrefix("#") ? hexaRGB.dropFirst() : hexaRGB[...])
switch chars.count {
case 3: chars = chars.flatMap { [$0, $0] }
case 6: break
default: return nil
}
self.init(red: .init(strtoul(String(chars[0...1]), nil, 16)) / 255,
green: .init(strtoul(String(chars[2...3]), nil, 16)) / 255,
blue: .init(strtoul(String(chars[4...5]), nil, 16)) / 255,
alpha: alpha)
}
convenience init?(hexaRGBA: String) {
var chars = Array(hexaRGBA.hasPrefix("#") ? hexaRGBA.dropFirst() : hexaRGBA[...])
switch chars.count {
case 3: chars = chars.flatMap { [$0, $0] }; fallthrough
case 6: chars.append(contentsOf: ["F","F"])
case 8: break
default: return nil
}
self.init(red: .init(strtoul(String(chars[0...1]), nil, 16)) / 255,
green: .init(strtoul(String(chars[2...3]), nil, 16)) / 255,
blue: .init(strtoul(String(chars[4...5]), nil, 16)) / 255,
alpha: .init(strtoul(String(chars[6...7]), nil, 16)) / 255)
}
convenience init?(hexaARGB: String) {
var chars = Array(hexaARGB.hasPrefix("#") ? hexaARGB.dropFirst() : hexaARGB[...])
switch chars.count {
case 3: chars = chars.flatMap { [$0, $0] }; fallthrough
case 6: chars.append(contentsOf: ["F","F"])
case 8: break
default: return nil
}
self.init(red: .init(strtoul(String(chars[2...3]), nil, 16)) / 255,
green: .init(strtoul(String(chars[4...5]), nil, 16)) / 255,
blue: .init(strtoul(String(chars[6...7]), nil, 16)) / 255,
alpha: .init(strtoul(String(chars[0...1]), nil, 16)) / 255)
}
}
if let textColor = UIColor(hexa: "00F") {
print(textColor) // r 0.0 g 0.0 b 1.0 a 1.0
}
if let textColor = UIColor(hexaRGB: "00F") {
print(textColor) // r 0.0 g 0.0 b 1.0 a 1.0
}
UIColor(hexaRGB: "#00F") // r 0.0 g 0.0 b 1.0 a 1.0
UIColor(hexaRGB: "#00F", alpha: 0.5) // r 0.0 g 0.0 b 1.0 a 0.5
UIColor(hexaRGB: "#0000FF") // r 0.0 g 0.0 b 1.0 a 1.0
UIColor(hexaRGB: "#0000FF", alpha: 0.5) // r 0.0 g 0.0 b 1.0 a 0.5
UIColor(hexaRGBA: "#0000FFFF") // r 0.0 g 0.0 b 1.0 a 1.0
UIColor(hexaRGBA: "#0000FF7F") // r 0.0 g 0.0 b 1.0 a 0.498
UIColor(hexaARGB: "#FF0000FF") // r 0.0 g 0.0 b 1.0 a 1.0
UIColor(hexaARGB: "#7F0000FF") // r 0.0 g 0.0 b 1.0 a 0.498