self.navigationItem.title = "设置本页面的导航栏"
    self.navigationController?.navigationBar.isTranslucent  = false
    //设置导航栏系统默认按钮图标和文字的颜色
    self.navigationController?.navigationBar.tintColor = .white
    // //导航栏的背景颜色
    self.navigationController?.navigationBar.barTintColor = .orange
    //设置导航栏标题文字的颜色
    self.navigationController?.navigationBar.titleTextAttributes =      [NSAttributedString.Key.foregroundColor: UIColor.white]

   //设置导航栏文字的其他样式

//self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.font:UIFont.italicSystemFont(ofSize: 18),NSAttributedString.Key.backgroundColor:UIColor.purple]


    //设置导航栏的背景颜色
   self.navigationController?.navigationBar.setBackgroundImage(UIImage(named: "gougou.jpg"), for: .default)


 // 设置导航栏背景图片
 let imagegougou = UIImage.init(named: "导航栏@2x")
 self.navigationController?.navigationBar.setBackgroundImage(imagegougou, for: .default)

  // 设置(去掉)导航栏底部线条
  self.navigationController?.navigationBar.shadowImage = UIImage()
        

   //第一种自定义返回按钮
    let leftButton = UIButton.init(frame: CGRect(x: 0, y: 0, width: 30, height: 30))

    leftButton.backgroundColor = .red
    leftButton.setImage(UIImage.init(named: "backWhit(gray)"), for: .normal)
    leftButton.setTitleColor(.white, for: .normal)
    leftButton.titleLabel?.font = UIFont.init(name: "Helvetica-Bold", size: 15)
    //leftButton.setTitle("返回", for: .normal)
    leftButton.addTarget(self, action: #selector(backClick), for: .touchUpInside)
    self.navigationItem.leftBarButtonItem = UIBarButtonItem(customView: leftButton)



    //另外一种方式设置导航栏图片按钮
    ///下面2行代码作用是不让按钮的图标给渲染成系统蓝色的
    var leftImage = UIImage.init(named: "backWhit(gray)")
     leftImage = leftImage!.withRenderingMode(.alwaysOriginal)

    self.navigationItem.leftBarButtonItem = UIBarButtonItem(image: leftImage, style: .plain, target: self, action: #selector(leftButtonClick))
   


//返回按钮方法的实现
 @objc func backClick() {
    
    self.navigationController?.popViewController(animated: true)
    
}

@objc func leftButtonClick () {

 self.navigationController?.popViewController(animated: true)

}