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
这是一个接受十六进制字符串并返回UIColor的函数。 (你可以输入十六进制字符串格式:#ffffff或ffffff)
用法:
var color1 = hexStringToUIColor("#d3d3d3")
Swift 5:(Swift 4+)
func hexStringToUIColor (hex:String) -> UIColor {
var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
if (cString.hasPrefix("#")) {
cString.remove(at: cString.startIndex)
}
if ((cString.count) != 6) {
return UIColor.gray
}
var rgbValue:UInt64 = 0
Scanner(string: cString).scanHexInt64(&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)
)
}
斯威夫特3:
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) {
return UIColor.gray
}
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)
)
}
斯威夫特2:
func hexStringToUIColor (hex:String) -> UIColor {
var cString:String = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet() as NSCharacterSet).uppercaseString
if (cString.hasPrefix("#")) {
cString = cString.substringFromIndex(cString.startIndex.advancedBy(1))
}
if ((cString.characters.count) != 6) {
return UIColor.grayColor()
}
var rgbValue:UInt32 = 0
NSScanner(string: cString).scanHexInt(&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)
)
}
沙德源代码:/ gist: de147c42d7b3063ef7bc
编辑:更新代码。谢谢,Hlung, jaytrixz, Ahmad F, Kegham K和Adam Waite!
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)
}
}
用户界面颜色:
extension UIColor {
convenience init(hex: Int) {
let components = (
R: CGFloat((hex >> 16) & 0xff) / 255,
G: CGFloat((hex >> 08) & 0xff) / 255,
B: CGFloat((hex >> 00) & 0xff) / 255
)
self.init(red: components.R, green: components.G, blue: components.B, alpha: 1)
}
}
CGColor:
extension CGColor {
class func colorWithHex(hex: Int) -> CGColorRef {
return UIColor(hex: hex).CGColor
}
}
使用
let purple = UIColor(hex: 0xAB47BC)
这是UIColor的一个Swift扩展,它采用十六进制字符串:
import UIKit
extension UIColor {
convenience init(hexString: String) {
// Trim leading '#' if needed
var cleanedHexString = hexString
if hexString.hasPrefix("#") {
// cleanedHexString = dropFirst(hexString) // Swift 1.2
cleanedHexString = String(hexString.characters.dropFirst()) // Swift 2
}
// String -> UInt32
var rgbValue: UInt32 = 0
NSScanner(string: cleanedHexString).scanHexInt(&rgbValue)
// UInt32 -> R,G,B
let red = CGFloat((rgbValue >> 16) & 0xff) / 255.0
let green = CGFloat((rgbValue >> 08) & 0xff) / 255.0
let blue = CGFloat((rgbValue >> 00) & 0xff) / 255.0
self.init(red: red, green: green, blue: blue, alpha: 1.0)
}
}
以编程方式添加颜色的最简单方法是使用ColorLiteral。
只要像例子中那样添加ColorLiteral属性,Xcode就会提示你一个你可以选择的颜色列表。这样做的好处是代码更少,添加HEX值或RGB。您还将从故事板中获得最近使用的颜色。
例子: self.view.backgroundColor = ColorLiteral
Swift 5:你可以在Xcode中创建颜色,如下图所示:
您应该命名颜色,因为您通过名称引用了颜色。如图2所示: