ios - 如何为 iPhone 8 屏幕与 iPhone X 及更高版本的底部 anchor 设置不同的常量？

Question

我做了一些研究，但我一直在寻找这个问题的答案:对于 iPhone X 之前的屏幕类型，我想从屏幕底部到菜单底部保持一个 -6 的常数.在 X 或更高版本上运行时，常量为 0，因为不需要。我试过验证 iOS 版本，但显然它总是默认为模型 8 上的 safeAreaLayoutGuide。我该怎么办？我只想到更多“手动”解决方案，例如屏幕高度，但我知道这不是可行的方法。请帮助。下面的代码。

view.addSubview(programMainMenu)
        if #available(iOS 11.0, *) { // gets called on 8.
            let safeGuide = self.view.safeAreaLayoutGuide
            let safeMenuConstraints = [
                programMainMenu.bottomAnchor.constraint(equalTo: safeGuide.bottomAnchor, constant: 0),
                programMainMenu.leadingAnchor.constraint(equalTo: safeGuide.leadingAnchor, constant: 8),
                programMainMenu.trailingAnchor.constraint(equalTo: safeGuide.trailingAnchor, constant: -8),
                programMainMenu.heightAnchor.constraint(equalToConstant: 90)
            ]
            NSLayoutConstraint.activate(safeMenuConstraints)
        } else {
            let mainMenuConstraints = [
                programMainMenu.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -6), // i need to have this on 8 but not above
                programMainMenu.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 8),
                programMainMenu.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -8),
                programMainMenu.heightAnchor.constraint(equalToConstant: 90)
            ]
            NSLayoutConstraint.activate(mainMenuConstraints)
        }*

Answer 1

你需要

 var cons = 0 // set values for it inside each switch case 

if UIDevice().userInterfaceIdiom == .phone {
    switch UIScreen.main.nativeBounds.height {
        case 1136:
            print("iPhone 5 or 5S or 5C")
           cons = ///

        case 1334:
            print("iPhone 6/6S/7/8")

        case 1920, 2208:
            print("iPhone 6+/6S+/7+/8+")

        case 2436:
            print("iPhone X/XS/11 Pro")

        case 2688:
            print("iPhone XS Max/11 Pro Max")

        case 1792:
            print("iPhone XR/ 11 ")

        default:
            print("Unknown")
        }
    }

然后在这里使用var

programMainMenu.bottomAnchor.constraint(equalTo: safeGuide.bottomAnchor,
constant:cons),