iOS 11 后退按钮问题答案

【问题标题】：iOS 11 back button issueiOS 11 后退按钮问题
【发布时间】：2023-04-05 08:10:01
【问题描述】：

if #available(iOS 11, *) {

    let view = UIView()
    view.frame = CGRect(x: 20, y: 0, width: 70, height: 50)
    let btn: UIButton = UIButton(frame: CGRect(x:-14, y: 0, width: 30, height: 27))
    btn.setBackgroundImage(UIImage(named: "BackArrow"), for: UIControlState());
    btn.addTarget(self, action: #selector(ExampleController.barBtnBackAction), for: UIControlEvents.touchUpInside)
    btn.center = CGPoint(x: btn.center.x,y :view.center.y)
    let tap = UITapGestureRecognizer(target: self, action: #selector(ExampleController.barBtnBackAction))
    view.addGestureRecognizer(tap)
    view.isUserInteractionEnabled = true
    view.backgroundColor = UIColor.black
    view.addSubview(btn)
    let leftButtonItem = UIBarButtonItem(customView: view)
    self.navigationItem.leftBarButtonItem = leftButtonItem
}

我正在使用此代码在 iOS 11 的导航栏中设置后退按钮，但效果不佳？用户在点击后退按钮时遇到问题我无法使用默认值，因为我想要对其进行自定义操作，并且在 iOS 11 之前我正在使用此代码：-（以下为 iOS 10）它工作正常。

let  barBtnNeg = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.fixedSpace, target: self, action: nil)
barBtnNeg.width = -15.0
let btn: UIButton = UIButton(frame: CGRect(x: 0, y: 0, width: 30, height: 27))
btn.setBackgroundImage(UIImage(named: "BackArrow"), for: UIControlState());
btn.addTarget(self, action: #selector(ExampleController.btnBackAction), for: UIControlEvents.touchUpInside)
let barBtnBack = UIBarButtonItem(customView: btn)
self.navigationItem.leftBarButtonItems = [barBtnNeg, barBtnBack]

如果我使用此代码，后箭头图像会向右移动（对齐错误），如果我减小帧静止图像的 x 轴，则不会移动，所以我必须使用上面的代码（如果 #available（iOS 11 , *))。

那么有什么解决方案可以通过自定义图像、自定义选择器（操作）和自定义对齐来解决后退按钮问题（导航栏）？

【问题讨论】：

标签： ios iphone swift uinavigationcontroller ios11

【解决方案1】：

为导航控制器添加此类

class NavigationBar: UINavigationBar {

    override func layoutSubviews() {
        super.layoutSubviews()

        for subview in self.subviews {
            let stringFromClass = NSStringFromClass(subview.classForCoder)

            if stringFromClass.contains("BarBackground") {
                subview.frame.origin.y = -20
                subview.frame.size.height = 64
            }
        }
    }
}

在你需要的地方创建导航栏

let navigationBar = NavigationBar(frame: CGRect(origin: CGPoint(x: 0,
                                                                        y: 20),
                                                        size: CGSize(width: view.frame.width,
                                                                     height: 40)))
        navigationBar.backgroundColor = UIColor(red: 46.0/255.0, green: 135.0/255.0, blue: 245.0/255.0, alpha: 1.0)
        navigationBar.isTranslucent = false
        let button1 = UIButton()
        button1.setImage(UIImage(named: "Back"), for: UIControlState())
        button1.addTarget(self, action: #selector (goBack(_:)), for: UIControlEvents.touchUpInside)
        button1.frame = CGRect(x: 0, y: 5, width: 20, height: 20)
        let barButton1 = UIBarButtonItem(customView: button1)
        self.navigationItem.leftBarButtonItem = barButton1
        navigationBar.items = [navigationItem]
        self.view .addSubview(navigationBar)

【讨论】：