UIKit - UIBarButtonItem(导航按钮)

UIBarButtonItem继承于UIBarItem，用于设置导航栏上的按钮组。

1.显示与隐藏回退按钮

self.navigationItem.hidesBackButton = true
self.navigationItem.setHidesBackButton(true, animated: true)

2.创建文字按钮

//左侧按钮
let leftButton = UIBarButtonItem(title: "Back", style: .plain, target: self, action: #selector(FirstPageViewController.prevButton))
    self.navigationItem.leftBarButtonItem = leftButton

//右侧按钮 
let rightButton = UIBarButtonItem(title: "Next", style: .plain, target: self, action: #selector(FirstPageViewController.nextButton))
    self.navigationItem.rightBarButtonItem = rightButton

3.创建系统自带按钮

let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: nil)
let cameraButton = UIBarButtonItem(barButtonSystemItem: .camera, target: self, action: nil)
let editButton = UIBarButtonItem(barButtonSystemItem: .edit, target: self, action: nil)
        
   //同时添加多个按钮
   self.navigationItem.rightBarButtonItems = [addButton,cameraButton,editButton]

4.添加自定义按钮

//自定义搜索框
let search = UITextField(frame: CGRect(x: 0, y: 0, width: 200, height: 25))
    search.backgroundColor = UIColor.gray
    search.placeholder = "请输入搜索内容"
    search.layer.masksToBounds = true
    search.layer.cornerRadius = 8
    search.layer.borderWidth = 2
    search.layer.borderColor = UIColor.blue.cgColor
let itemButton = UIBarButtonItem(customView: search)

//文本 
let txt = UILabel(frame: CGRect(x: 0, y: 0, width: 40, height: 25))
    txt.text = "搜索"
let txtButton = UIBarButtonItem(customView: txt)
      
    //添加按钮组  
    self.navigationItem.rightBarButtonItems = [itemButton, txtButton]

5.按钮样式

let leftButton = UIBarButtonItem(title: "Back", style: .plain, target: self, action: #selector(FirstPageViewController.prevButton))
    //字体颜色
    leftButton.tintColor = UIColor.red
    //按钮背景图片
    leftButton.setBackgroundImage(UIImage(named:"image"), for: .normal, barMetrics: .default)
    
    self.navigationItem.leftBarButtonItem = leftButton

效果如下图: