xcode - 导航栏颜色问题

Question

我在匹配颜色时遇到一些问题。

我之前问过类似的问题，但现在遇到了同样的问题。我已将半透明度设置为 false 并将此十六进制颜色转换为 UIColor:

008A2E

问题是它仍然不符合应有的效果(数字色度计给出不同的值)。是因为颜色被剪裁了吗？有办法解决这个问题吗？

谢谢

Answer 1

我在这里为此问题编写了一个扩展，将其另存为 swift 类并导入您的项目。

import Foundation
import UIKit

extension UIColor {
    convenience init(hex: Int, alpha: CGFloat = 1.0) {
        let red = CGFloat((hex & 0xFF0000) >> 16) / 255.0
        let green = CGFloat((hex & 0xFF00) >> 8) / 255.0
        let blue = CGFloat((hex & 0xFF)) / 255.0
        self.init(red:red, green:green, blue:blue, alpha:alpha)
    }

    convenience init(rgba: String) {
        var red:   CGFloat = 0.0
        var green: CGFloat = 0.0
        var blue:  CGFloat = 0.0
        var alpha: CGFloat = 1.0

        if rgba.hasPrefix("#") {
            let index   = advance(rgba.startIndex, 1)
            let hex     = rgba.substringFromIndex(index)
            let scanner = NSScanner(string: hex)
            var hexValue: CUnsignedLongLong = 0
            if scanner.scanHexLongLong(&hexValue) {
                switch (count(hex)) {
                case 3:
                    red   = CGFloat((hexValue & 0xF00) >> 8)       / 15.0
                    green = CGFloat((hexValue & 0x0F0) >> 4)       / 15.0
                    blue  = CGFloat(hexValue & 0x00F)              / 15.0
                case 4:
                    red   = CGFloat((hexValue & 0xF000) >> 12)     / 15.0
                    green = CGFloat((hexValue & 0x0F00) >> 8)      / 15.0
                    blue  = CGFloat((hexValue & 0x00F0) >> 4)      / 15.0
                    alpha = CGFloat(hexValue & 0x000F)             / 15.0
                case 6:
                    red   = CGFloat((hexValue & 0xFF0000) >> 16)   / 255.0
                    green = CGFloat((hexValue & 0x00FF00) >> 8)    / 255.0
                    blue  = CGFloat(hexValue & 0x0000FF)           / 255.0
                case 8:
                    red   = CGFloat((hexValue & 0xFF000000) >> 24) / 255.0
                    green = CGFloat((hexValue & 0x00FF0000) >> 16) / 255.0
                    blue  = CGFloat((hexValue & 0x0000FF00) >> 8)  / 255.0
                    alpha = CGFloat(hexValue & 0x000000FF)         / 255.0
                default:
                    print("Invalid RGB string, number of characters after '#' should be either 3, 4, 6 or 8")
                }
            } else {
                println("Scan hex error")
            }
        } else {
            print("Invalid RGB string, missing '#' as prefix")
        }
        self.init(red:red, green:green, blue:blue, alpha:alpha)
    }
}

usage

navigationController.navigationBar.barTintColor = UIColor(hex: 0x008A2E, alpha: 1.0)