我想为整个应用程序的 UINavigationBar 底部设置一些阴影。这是我尝试过但不起作用的方法:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
UINavigationBar.appearance().layer.shadowOffset = CGSizeMake(0, 3)
UINavigationBar.appearance().layer.shadowRadius = 3.0
UINavigationBar.appearance().layer.shadowColor = UIColor.yellowColor().CGColor
UINavigationBar.appearance().layer.shadowOpacity = 0.7
}
请告诉我该怎么做?
更新: 通过继承 UINavigationController 解决
import UIKit
class ShadowUINavigationController: UINavigationController {
override func viewWillAppear(animated: Bool) {
let darkColor: CGColorRef = UIColor(hex: 0x212121).CGColor
let lightColor: CGColorRef = UIColor.clearColor().CGColor
let navigationBarBottom: CGFloat = self.navigationBar.frame.origin.y + self.navigationBar.frame.size.height + 20
println(self.navigationBar.frame.origin.y)
println(self.navigationBar.frame.size.height)
println(navigationBarBottom)
let newShadow: CAGradientLayer = CAGradientLayer()
newShadow.frame = CGRectMake(0, navigationBarBottom, self.view.frame.size.width, 1)
newShadow.colors = [darkColor, lightColor]
self.view.layer.addSublayer(newShadow)
super.viewWillAppear(animated)
}
}
最佳答案
更好的解决方案仍然使用外观并且不需要您子类化 UINavigationBar 并向每个导航 Controller 添加代码,将是:
扩展 UINavigationBar
extension UINavigationBar {
var castShadow : String {
get { return "anything fake" }
set {
self.layer.shadowOffset = CGSizeMake(0, 3)
self.layer.shadowRadius = 3.0
self.layer.shadowColor = UIColor.yellowColor().CGColor
self.layer.shadowOpacity = 0.7
}
}
}
并添加应用范围内的外观规则(例如在 appdelegate "didFinishLaunchingWithOptions"中)
UINavigationBar.appearance().castShadow = ""
关于ios - UINavigationBar 在 AppDelegate.swift 中设置自定义阴影,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31756230/