Swift擴充套件UIColor
阿新 • • 發佈:2018-12-17
import Foundation import UIKit extension UIColor { convenience init(hex: String) { self.init(hex: hex, alpha: 1) } convenience init(hex: String, alpha: CGFloat) { let scanner = Scanner(string: hex) scanner.scanLocation = 0 var rgbValue: UInt64 = 0 scanner.scanHexInt64(&rgbValue) let r = (rgbValue & 0xff0000) >> 16 let g = (rgbValue & 0xff00) >> 8 let b = rgbValue & 0xff self.init( red: CGFloat(r) / 0xff, green: CGFloat(g) / 0xff, blue: CGFloat(b) / 0xff, alpha: alpha ) } convenience init(red: Int, green: Int, blue: Int) { self.init(red: red, green: green, blue: blue, alpha: 1) } convenience init(red: Int, green: Int, blue: Int, alpha: CGFloat) { assert(red >= 0 && red <= 255, "Invalid red component") assert(green >= 0 && green <= 255, "Invalid green component") assert(blue >= 0 && blue <= 255, "Invalid blue component") self.init( red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0 ) } static func random() -> UIColor { return UIColor(red: .random(), green: .random(), blue: .random(), alpha: 0.7) } }
import UIKit
extension UIFont {
class func defaultFont(size: CGFloat) -> UIFont {
return UIFont(name: "Helvetica", size: size) ?? UIFont.systemFont(ofSize: size)
}
}