如何解决在swift中点击tabBar时如何显示不同的ViewController
我有三个 viewController,其中两个连接到一个 tabBarController。因此,当点击 tabBar 项 here is my storyboard
时,应用程序应显示两个 vc 的依赖 Bool 值之一import UIKit
class TabBarController: UITabBarController,UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
}
func tabBarController(_ tabBarController: UITabBarController,didSelect viewController: UIViewController) {
let userLoggedIn: Bool!
if tabBarController.selectedindex == 1{
if userLoggedIn == true{
// show firstVC
}else{
// show secondVC
}
}
}
}
解决方法
您可以使用 childViewController,其父是来自 Storyboard 的 ViewController。
override func viewDidLoad() {
super.viewDidLoad()
///add two ChildVC here,hide 1 ifneeded
}
当点击此标签时,您会选中 userLoggedIn
。
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
if userLoggedIn == true {
/// show first childVC
/// hide second childVC
} else {
/// hide first childVC
/// show second childVC
}
}
您可以查看演示:Demo
,在修改 userLoggedIn 变量时简单地设置 viewController 列表(假设 userLoggedIn 是 TabBarCOntroller 实例变量):
class TabBarC: UITabBarController {
@IBOutlet var firstVC : FirstViewController!
@IBOutlet var secondVC : SecondViewController!
@IBOutlet var thirdVC : ThirdViewController!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
for vc in self.viewControllers! {
if let fv = vc as? FirstViewController {
firstVC = fv
} else if let fv = vc as? SecondViewController {
secondVC = fv
} else if let fv = vc as? ThirdViewController {
thirdVC = fv
}
}
}
var userLoggedIn : Bool = false {
didSet {
if userLoggedIn {
self.viewControllers = [firstVC,thirdVC]
} else {
self.viewControllers = [secondVC,thirdVC]
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self. userLoggedIn = false
}
override func tabBar(_ tabBar: UITabBar,didSelect item: UITabBarItem) {
if item.tag == 3 { // For purpose of test i set tag for 3 VC to 1 for firsttVC,2 for secondVC,3 for thirdVC
// for test : change login value each time thirdVC is selected
userLoggedIn = ! userLoggedIn
}
}
因此,每次从代码中的任何位置设置 userLoggedIn 时,选项卡都会显示所需的选项卡栏项目。 3 VC 被添加到stpryboard 中的tabbar。 选择第三个VC时,第一个标签栏项在一到二之间变化
,只需像这样将 .overCurrentContext 添加到 viewDidLoad 中的 modalPresentationStyle。
let newVC = self.storyboard?.instantiateViewController(withIdentifier:"secondVC")
newVC?.modalPresentationStyle = .overCurrentContext
self.present(newVC!,animated: false,completion: nil)
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。