swift下,给控件设置颜色,有好几种方式,rbg,16进制hex数值,16进制hex字符串
我们可以统一一下,满足各种方式的设置
定义一个ColorProvider协议,针对不同类型的颜色,给定默认实现

实现之前,给大家看一下使用方式

 UIColor.dynamic(0xFFFFFF, dark: 0x000000)
 
 UIColor.dynamic(UIColor.white, dark: UIColor.black)
    
 UIColor.dynamic(0xFFFFFF, dark: "0x000000")
 
 0x1B1B1B.uiColor
 
 UIColor(red: 129, green: 21, blue: 12)
 
 "0xffffff".uiColor
 
 "#ffffff".uiColor
 
 0x7986E6.cgColor

利用协议来扩展Color

public protocol ColorProvider {
    var uiColor: UIColor { get }
    var cgColor: CGColor { get }
}

给cgColor一个默认实现

extension ColorProvider {
   public var cgColor: CGColor {
        return uiColor.cgColor
    }
}

扩展

/// 16进制数值
public struct HexAColor {
   public let hex: Int
   public let alpha: CGFloat
   public init(hex: Int, alpha: CGFloat = 1.0) {
        self.alpha = alpha
        self.hex = hex
    }
}

/// 16进制字符串
public struct StrHexColor {
   public let hex: String
   public let alpha: CGFloat
   public init(hex: String, alpha: CGFloat = 1.0) {
        self.alpha = alpha
        self.hex = hex
    }
}

/// RGB
public struct RGBAColor {
   let red: Int
   let green: Int
   let blue: Int
   let alpha: CGFloat
   public init(red: Int, green: Int, blue: Int, alpha: CGFloat = 1.0) {
        self.alpha = alpha
        self.blue = blue
        self.green = green
        self.red = red
    }
}

extension默认实现

/// HEX 16进制
extension HexAColor: ColorProvider {
    public var uiColor: UIColor {
        let red   =  Double((hex & 0xFF0000) >> 16) / 255.0
        let green =  Double((hex & 0xFF00)   >> 8 ) / 255.0
        let blue  =  Double( hex & 0xFF   ) / 255.0
        return UIColor.init(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: alpha)
    }
}

/// HEX 字符串
extension StrHexColor: ColorProvider {
    public var uiColor: UIColor {
        return hex.getColor(alpha: alpha)
    }
}

/// RGB
extension RGBAColor: ColorProvider {
    public var uiColor: UIColor {
        UIColor(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: alpha)
    }
}

UIColor

extension UIColor: ColorProvider {
    public var uiColor: UIColor {
        return self
    }
}

Int

extension Int: ColorProvider {
    public var uiColor: UIColor {
        let red   =  Double((self & 0xFF0000) >> 16) / 255.0
        let green =  Double((self & 0xFF00)   >> 8 ) / 255.0
        let blue  =  Double( self & 0xFF   ) / 255.0
        return UIColor.init(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: 1)
    }
}

String

extension String: ColorProvider {
    public var uiColor: UIColor {
        return getColor(alpha: 1)
    }
    
    func getColor(alpha: CGFloat) -> UIColor {
        var cstr = trimmingCharacters(in: CharacterSet.whitespacesAndNewlines).uppercased() as NSString
        if cstr.length < 6 { return .clear }
        if cstr.hasPrefix("0X") {
            cstr = cstr.substring(from: 2) as NSString
        } else if cstr.hasPrefix("#") {
          cstr = cstr.substring(from: 1) as NSString
        }
         if cstr.length != 6 { return .clear }
        var range = NSRange.init()
        range.location = 0
        range.length = 2
        //r
        let rStr = cstr.substring(with: range);
        //g
        range.location = 2
        let gStr = cstr.substring(with: range)
        //b
        range.location = 4
        let bStr = cstr.substring(with: range)
        var r :UInt32 = 0x0
        var g :UInt32 = 0x0
        var b :UInt32 = 0x0
        Scanner.init(string: rStr).scanHexInt32(&r)
        Scanner.init(string: gStr).scanHexInt32(&g)
        Scanner.init(string: bStr).scanHexInt32(&b)
        return UIColor.init(red: CGFloat(r)/255.0, green: CGFloat(g)/255.0, blue: CGFloat(b)/255.0, alpha: alpha)
    }
}

浅色模式和深色模式下,设置动态颜色

extension UIColor {
    /// 设置动态颜色,可以直接设置Int类型的hex值,
    /// - Parameter light: 浅色模式下的颜色
    /// - Parameter dark: 深色模式下的颜色
    public static func dynamic(_ light: ColorProvider, dark: ColorProvider, alphaComponent alpha: CGFloat? = nil) -> UIColor {
        if #available(iOS 13.0, *) {
            return UIColor.init { (traitCollection) -> UIColor in
                if let alpha = alpha {
                    return traitCollection.userInterfaceStyle != .light ? dark.uiColor.withAlphaComponent(alpha) : light.uiColor.withAlphaComponent(alpha)
                }
                return traitCollection.userInterfaceStyle != .light ? dark.uiColor : light.uiColor
            }
        } else {
            if let alpha = alpha {
                return light.uiColor.withAlphaComponent(alpha)
            }
            return light.uiColor
        }
    }

给UIColor扩展一些常用的方法

 extension UIColor {
   /// rgb来颜色,不用再除255, 如  UIColor(red: 129, green: 21, blue: 12)
    ///
    /// - Parameters:
    ///   - red: red component.
    ///   - green: green component.
    ///   - blue: blue component.
    ///   - transparency: optional transparency value (default is 1).
    convenience public init?(red: Int, green: Int, blue: Int, transparency: CGFloat = 1) {
        guard red >= 0 && red <= 255 else { return nil }
        guard green >= 0 && green <= 255 else { return nil }
        guard blue >= 0 && blue <= 255 else { return nil }
        
        var trans = transparency
        if trans < 0 { trans = 0 }
        if trans > 1 { trans = 1 }
    
        self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: trans)
    }

    /// 随机色
    public static var random: UIColor {
        let red = Int.random(in: 0...255)
        let green = Int.random(in: 0...255)
        let blue = Int.random(in: 0...255)
        return UIColor(red: red, green: green, blue: blue)!
    }
}