importUIKit
classViewController:UIViewController{
varcount = 0
//声明导航条
varnavigationBar:UINavigationBar?
overridefuncviewDidLoad() {
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()
}
overridefuncdidReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//增加导航项函数
funconAdd(){
count++
//给导航条增加导航项
navigationBar?.pushNavigationItem(onMakeNavitem(), animated:true)
}
//删除导航项函数
funconRemove(){
ifcount > 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
funconMakeNavitem()->UINavigationItem{
varnavigationItem =UINavigationItem()
//创建左边按钮
varleftBtn =UIBarButtonItem(barButtonSystemItem:UIBarButtonSystemItem.Add,
target:self, action:"onAdd")
//创建右边按钮
varrightBtn =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)
returnnavigationItem
}
}
