我试图在Swift中使用十六进制颜色值,而不是UIColor允许您使用的少数标准值,但我不知道如何做到这一点。
示例:我如何使用#ffffff作为颜色?
我试图在Swift中使用十六进制颜色值,而不是UIColor允许您使用的少数标准值,但我不知道如何做到这一点。
示例:我如何使用#ffffff作为颜色?
当前回答
我做了一个小函数,把它放在我可以全局使用它的地方,在swift 2.1中工作得很好:
func getColorFromHex(rgbValue:UInt32)->UIColor{
let red = CGFloat((rgbValue & 0xFF0000) >> 16)/255.0
let green = CGFloat((rgbValue & 0xFF00) >> 8)/255.0
let blue = CGFloat(rgbValue & 0xFF)/255.0
return UIColor(red:red, green:green, blue:blue, alpha:1.0)
}
用法:
getColorFromHex(0xffffff)
其他回答
Swift 5 (Swift 4, Swift 3) UIColor扩展:
extension UIColor {
convenience init(hexString: String) {
let hex = hexString.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
var int = UInt64()
Scanner(string: hex).scanHexInt64(&int)
let a, r, g, b: UInt64
switch hex.count {
case 3: // RGB (12-bit)
(a, r, g, b) = (255, (int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
case 6: // RGB (24-bit)
(a, r, g, b) = (255, int >> 16, int >> 8 & 0xFF, int & 0xFF)
case 8: // ARGB (32-bit)
(a, r, g, b) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
default:
(a, r, g, b) = (255, 0, 0, 0)
}
self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(a) / 255)
}
}
用法:
let darkGrey = UIColor(hexString: "#757575")
斯威夫特2。x版本:
extension UIColor {
convenience init(hexString: String) {
let hex = hexString.stringByTrimmingCharactersInSet(NSCharacterSet.alphanumericCharacterSet().invertedSet)
var int = UInt32()
NSScanner(string: hex).scanHexInt(&int)
let a, r, g, b: UInt32
switch hex.characters.count {
case 3: // RGB (12-bit)
(a, r, g, b) = (255, (int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
case 6: // RGB (24-bit)
(a, r, g, b) = (255, int >> 16, int >> 8 & 0xFF, int & 0xFF)
case 8: // ARGB (32-bit)
(a, r, g, b) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
default:
(a, r, g, b) = (255, 0, 0, 0)
}
self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(a) / 255)
}
}
你可以在UIColor上使用这个扩展,它将你的字符串(十六进制,RGBA)转换为UIColor,反之亦然。
extension UIColor {
//Convert RGBA String to UIColor object
//"rgbaString" must be separated by space "0.5 0.6 0.7 1.0" 50% of Red 60% of Green 70% of Blue Alpha 100%
public convenience init?(rgbaString : String){
self.init(ciColor: CIColor(string: rgbaString))
}
//Convert UIColor to RGBA String
func toRGBAString()-> String {
var r: CGFloat = 0
var g: CGFloat = 0
var b: CGFloat = 0
var a: CGFloat = 0
self.getRed(&r, green: &g, blue: &b, alpha: &a)
return "\(r) \(g) \(b) \(a)"
}
//return UIColor from Hexadecimal Color string
public convenience init?(hexString: String) {
let r, g, b, a: CGFloat
if hexString.hasPrefix("#") {
let start = hexString.index(hexString.startIndex, offsetBy: 1)
let hexColor = hexString.substring(from: start)
if hexColor.characters.count == 8 {
let scanner = Scanner(string: hexColor)
var hexNumber: UInt64 = 0
if scanner.scanHexInt64(&hexNumber) {
r = CGFloat((hexNumber & 0xff000000) >> 24) / 255
g = CGFloat((hexNumber & 0x00ff0000) >> 16) / 255
b = CGFloat((hexNumber & 0x0000ff00) >> 8) / 255
a = CGFloat(hexNumber & 0x000000ff) / 255
self.init(red: r, green: g, blue: b, alpha: a)
return
}
}
}
return nil
}
// Convert UIColor to Hexadecimal String
func toHexString() -> String {
var r: CGFloat = 0
var g: CGFloat = 0
var b: CGFloat = 0
var a: CGFloat = 0
self.getRed(&r, green: &g, blue: &b, alpha: &a)
return String(
format: "%02X%02X%02X",
Int(r * 0xff),
Int(g * 0xff),
Int(b * 0xff))
}
}
public static func hexStringToUIColor (hex:String) -> UIColor {
var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
if (cString.hasPrefix("#")) {
cString.remove(at: cString.startIndex)
}
if ((cString.characters.count) == 6) {
var rgbValue:UInt32 = 0
Scanner(string: cString).scanHexInt32(&rgbValue)
return UIColor(
red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
alpha: CGFloat(1.0)
)
}else if ((cString.characters.count) == 8) {
var rgbValue:UInt32 = 0
Scanner(string: cString).scanHexInt32(&rgbValue)
return UIColor(
red: CGFloat((rgbValue & 0x00FF0000) >> 16) / 255.0,
green: CGFloat((rgbValue & 0x0000FF00) >> 8) / 255.0,
blue: CGFloat(rgbValue & 0x000000FF) / 255.0,
alpha: CGFloat((rgbValue & 0xFF000000) >> 24) / 255.0
)
}else{
return UIColor.gray
}
}
如何使用
var color: UIColor = hexStringToUIColor(hex: "#00ff00"); // Without transparency
var colorWithTransparency: UIColor = hexStringToUIColor(hex: "#dd00ff00"); // With transparency
Swift 5.3 & SwiftUI:通过UIColor支持十六进制和CSS颜色名称
依据代码
斯威夫特包
SwiftUI包
字符串的例子:
橙子、酸橙、番茄等。 Clear, Transparent, nil和空字符串产生[UIColor clearColor] 美国广播公司 abc7 # abc7 00飞行符 # 00飞行符 00 ffff77
操场上的输出:
修复了“'scanHexInt32' was deprecated in iOS 13.0”的警告。
示例应该可以在Swift2.2及以上版本(Swift2. exe)上运行。x, Swift3。x, Swift4。x, Swift5.x):
extension UIColor {
// hex sample: 0xf43737
convenience init(_ hex: Int, alpha: Double = 1.0) {
self.init(red: CGFloat((hex >> 16) & 0xFF) / 255.0, green: CGFloat((hex >> 8) & 0xFF) / 255.0, blue: CGFloat((hex) & 0xFF) / 255.0, alpha: CGFloat(255 * alpha) / 255)
}
convenience init(_ hexString: String, alpha: Double = 1.0) {
let hex = hexString.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
var int = UInt64()
Scanner(string: hex).scanHexInt64(&int)
let r, g, b: UInt64
switch hex.count {
case 3: // RGB (12-bit)
(r, g, b) = ((int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
case 6: // RGB (24-bit)
(r, g, b) = (int >> 16, int >> 8 & 0xFF, int & 0xFF)
default:
(r, g, b) = (1, 1, 0)
}
self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(255 * alpha) / 255)
}
convenience init(r: CGFloat, g: CGFloat, b: CGFloat, a: CGFloat = 1) {
self.init(red: (r / 255), green: (g / 255), blue: (b / 255), alpha: a)
}
}
像下面这样使用它们:
UIColor(0xF54A45)
UIColor(0xF54A45, alpha: 0.7)
UIColor("#f44")
UIColor("#f44", alpha: 0.7)
UIColor("#F54A45")
UIColor("#F54A45", alpha: 0.7)
UIColor("F54A45")
UIColor("F54A45", alpha: 0.7)
UIColor(r: 245.0, g: 73, b: 69)
UIColor(r: 245.0, g: 73, b: 69, a: 0.7)