Swift

与导航控制器（UINavigationController）同时实现导航条和页面切换功能不同。

导航条（UINavgationBar）可以单独使用，添加至任何的UIView中。UINavigationBar比较重要的属性为，左侧按钮，中间的标题，以及右侧按钮。

下面是一个使用样例，点击左侧加号会添加一个新的导航项，点击右侧Cancel会移除当前最上层导航项。

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

import UIKit   class ViewController: UIViewController {           var count = 0     //声明导航条     var navigationBar:UINavigationBar?       override func viewDidLoad() {         super.viewDidLoad()         // Do any additional setup after loading the view, typically from a nib.         //实例化导航条         navigationBar = UINavigationBar(frame: CGRectMake(0, 20, 320, 44))         self.view.addSubview(navigationBar!)         onAdd()     }       override func didReceiveMemoryWarning() {         super.didReceiveMemoryWarning()         // Dispose of any resources that can be recreated.     }           //增加导航项函数     func onAdd(){         count++         //给导航条增加导航项         navigationBar?.pushNavigationItem(onMakeNavitem(), animated: true)     }           //删除导航项函数     func onRemove(){         if count > 1{             //减少导航项数量             count--             //从导航条中移除最后一个导航项             navigationBar?.popNavigationItemAnimated(true)         }     }           //创建一个导航项     func onMakeNavitem()->UINavigationItem{         var navigationItem = UINavigationItem()         //创建左边按钮         var leftBtn = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Add,             target: self, action: "onAdd")         //创建右边按钮         var rightBtn = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Cancel,             target: self, action: "onRemove")         //设置导航栏标题         navigationItem.title = "第(count)个导航项"         //设置导航项左边的按钮         navigationItem.setLeftBarButtonItem(leftBtn, animated: true)         //设置导航项右边的按钮         navigationItem.setRightBarButtonItem(rightBtn, animated: true)         return navigationItem     } }