swift UIColor + hex

Posted 2021-05-19

// .xcassets で色のセットを扱えるようになったので、(Xcodeの環境なら)そっちを使った方が得策。

extension UIColor {
    class func hex(_ str: String, alpha : CGFloat) -> UIColor {
        let scanner = Scanner(string: str)
        let ignoredCharacterSet = CharacterSet(charactersIn: "#")
        scanner.charactersToBeSkipped = ignoredCharacterSet
        var color: UInt32 = 0
        if scanner.scanHexInt32(&color) {
            let r = CGFloat((color & 0xFF0000) >> 16) / 255.0
            let g = CGFloat((color & 0x00FF00) >> 8) / 255.0
            let b = CGFloat(color & 0x0000FF) / 255.0
            return UIColor(red:r, green:g, blue:b, alpha:alpha)
        }
        print("invalid hex string")
        return UIColor.clear
    }
}