Mhy我的导航栏颜色在Swift中没有变化？

我制作了一个自定义的

NavigationBar

，用于所有屏幕，如下所示：

 import Foundation
 import UIKit

extension UIViewController {

func setUpNavigationBar() {

    self.navigationController?.navigationBar.backgroundColor = .yellow
    self.navigationController?.navigationBar.isTranslucent = false
    self.navigationController?.navigationBar.layer.masksToBounds = false
    
    let menuImageView = UIImageView.init(image: #imageLiteral(resourceName: "menu8"))
    menuImageView.tintColor = .darkGray
    menuImageView.frame = CGRect(x:0.0,y:0.0, width:25,height:25.0)
    menuImageView.contentMode = .scaleAspectFit
    menuImageView.widthAnchor.constraint(equalToConstant: 25).isActive = true
    menuImageView.heightAnchor.constraint(equalToConstant: 25).isActive = true
    menuImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(menuClick)))
    let btnMenu = UIBarButtonItem(customView: menuImageView)
    
    self.navigationItem.setLeftBarButton(btnMenu, animated: true)
}

@objc func menuClick(){
    SideMenuController.preferences.basic.menuWidth = self.view.frame.width*0.8
    if !(self.sideMenuController?.isMenuRevealed ?? false){
        self.sideMenuController?.revealMenu()
    }
  }    
}

调用

SignupVC视图将显示如下所示：

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(true)
          setUpNavigationBar()
}

使用上述代码，我不会得到黄色的导航栏。我在SignupVC中获得了
导航栏
，就像唯一的白色一样。无
leftbutton
菜单。为什么？我错在哪里

谢谢。
更改背景：

navigationController?.navigationBar.barTintColor = UIColor.yellow

测试合格100%

此代码：

func setUpNavigationBar() {

    navigationController?.navigationBar.barTintColor = UIColor.yellow
    self.navigationController?.navigationBar.isTranslucent = false
    self.navigationController?.navigationBar.layer.masksToBounds = false
    
    let menuImageView = UIImageView.init(image: UIImage.init(named: "day")!)
    menuImageView.tintColor = .darkGray
    menuImageView.frame = CGRect(x:0.0,y:0.0, width:25,height:25.0)
    menuImageView.contentMode = .scaleAspectFit
    menuImageView.widthAnchor.constraint(equalToConstant: 25).isActive = true
    menuImageView.heightAnchor.constraint(equalToConstant: 25).isActive = true
    menuImageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(menuClick)))
    let btnMenu = UIBarButtonItem(customView: menuImageView)
    
    self.navigationItem.setLeftBarButton(btnMenu, animated: true)
}

您是否尝试过检查self.navigationController

是否为

nil

？@EmilioPelaez在哪里？我应该试试吗？怎么做？这里是self.navigationController？.navigationBar.backgroundColor=.yellow检查self是否正确。navigationcontroller为零或not@EmilioPelaez我试过了。。不是零