import UIKit
extension UIColor {
//用数值初始化颜色,便于生成设计图上标明的十六进制颜色
convenience init(valueRGB: UInt, alpha: CGFloat) {
self.init(
red: CGFloat((valueRGB & 0xFF0000) >> 16) / 255.0,
green: CGFloat((valueRGB & 0x00FF00) >> 8) / 255.0,
blue: CGFloat(valueRGB & 0x0000FF) / 255.0,
alpha: alpha
)
}
convenience init(hexColor: String) {
// 用十六进制颜色创建UIColor
// 存储转换后的数值
var red:UInt32 = 0, green:UInt32 = 0, blue:UInt32 = 0
// 分别转换进行转换
Scanner(string: hexColor[0..<2]).scanHexInt32(&red)
Scanner(string: hexColor[2..<4]).scanHexInt32(&green)
Scanner(string: hexColor[4..<6]).scanHexInt32(&blue)
self.init(red: CGFloat(red)/255.0, green: CGFloat(green)/255.0, blue: CGFloat(blue)/255.0, alpha: 1.0)
}
}
extension String {
// String使用下标截取字符串
// 例: "示例字符串"[0..<2] 结果是 "示例"
subscript (r: Range<Int>) -> String {
get {
let startIndex = self.index(self.startIndex, offsetBy: r.lowerBound)
let endIndex = self.index(self.startIndex, offsetBy: r.upperBound)
return self[startIndex..<endIndex]
}
}
}