[iOS] [Swift] Hex To UIColor

//Input Format : String "0x(16진수 RGB색상 값)"
let input = "0x554433"//"0x13123ac"

//https://stackoverflow.com/questions/27189338/swift-native-functions-to-have-numbers-as-hex-strings
// Int(_, radix: ) can't deal with the '0x' prefix. NSScanner can handle hex
// with or without the '0x' prefix
 
let scanner = Scanner(string: input)
var value: UInt64 = 0

if scanner.scanHexInt64(&value) { // value가 hex값으로 변환한 Int값.
	print("Decimal: \(value) ::: \(Int(value))")
    //UIColor(netHex: Int)를 이용해서 색상 변화 가능
    //self.contentView.backgroundColor = .init(netHex: Int(value))
    
    
    //아래는 값 확인용 코드.
    let test2 = String(value, radix: 16)
    print("HexCheck: \(test2)")
    print("Hex: 0x\(String(value, radix: 16))")
    /*  
    let text3 = 0x554433
    let red = (text3 >> 16) & 0xff
    let green = (text3 >> 8) & 0xff
    let blue = text3 & 0xff
    print("CheckRGB ::: \n\(red) || \(green) || \(blue)\n\(text3 >> 16) || \(text3 >> 8) || \(text3)")
	*/
}​

extension UIColor {
    
    convenience init(red: Int, green: Int, blue: Int, alpha: CGFloat = 1.0) {
        self.init(red: CGFloat(red) / 255.0,
                  green: CGFloat(green) / 255.0,
                  blue: CGFloat(blue) / 255.0,
                  alpha: alpha)
    }
    
    //아래의 init(netHex: Int)들의 경우, netHex parameter에 0x000000~0xffffff값을 넣으면 된다.
    // UIColor(netHex:0xFFFFFF)
    convenience init(netHex:Int) {
        let red = (netHex >> 16) & 0xff
        let green = (netHex >> 8) & 0xff
        let blue = netHex & 0xff
        
        self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
        
    }
    
    // UIColor(netHex:0xFFFFFF, alpha:1.0)
    convenience init(netHex:Int, alpha:CGFloat) {
        let red = (netHex >> 16) & 0xff
        let green = (netHex >> 8) & 0xff
        let blue = netHex & 0xff
        
        self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: alpha)
    }
    
    //string input을 이용해서 직접적으로 변환을 시켜주는 코드.
    convenience public init?(hex: String, _ alpha: CGFloat = 1.0) {
        let r, g, b, a: CGFloat
        
        if hex.hasPrefix("#") {
            let start = hex.index(hex.startIndex, offsetBy: 1)
            let hexColor = String(hex[start...])
            
            if hexColor.count == 6 {
                let scanner = Scanner(string: hexColor)
                var hexNumber: UInt64 = 0
                
                if scanner.scanHexInt64(&hexNumber) {
                    r = CGFloat((hexNumber & 0xff0000) >> 16) / 255
                    g = CGFloat((hexNumber & 0x00ff00) >> 8) / 255
                    b = CGFloat((hexNumber & 0x0000ff)) / 255
                    a = alpha
                    
                    self.init(red: r, green: g, blue: b, alpha: a)
                    return
                }
            }
        }
        return nil
    }
}