我正在使用此代码从十六进制值创建UIColor。它的工作完美。
extension UIColor { convenience init(red: Int, green: Int, blue: Int) { assert(red >= 0 && red <= 255, "Invalid red component") assert(green >= 0 && green <= 255, "Invalid green component") assert(blue >= 0 && blue <= 255, "Invalid blue component") self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0) } convenience init(netHex:Int) { self.init(red:(netHex >> 16) & 0xff, green:(netHex >> 8) & 0xff, blue:netHex & 0xff) } }
用法:
var textColor = UIColor(netHex: 0xffffff)
此代码非常适合Int十六进制代码。但是它需要十六进制代码0xffffff作为Int类型。我正在从Web服务获取十六进制代码。就像“
0xffffff”(String)转换为0xffffff(Int)。
我需要这样的东西
var textColor = UIColor(netHex: "0xffffff")
或更像这样:
var textColor = UIColor(netHex: "#ffffff")
提前致谢。
Xcode 9•Swift 4或更高版本
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