我有以下带有 2 个项目的 TabBarController。它显示正确。
我正在调用setupItems()
当something
时从另一个 Controller 运行改变它的值。
函数调用正确,问题是navFirstController.tabBarItem.image
没有更新。
class TabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
setupItems()
}
func setupItems() {
let scale: CGFloat = 0.35
let navFirstController = UINavigationController(rootViewController: FirstController())
let navSecondController = UINavigationController(rootViewController: SecondController())
navSecondController.tabBarItem.image = UIImage.scale(image: UIImage(named: "image2")!, by: scale)
navSecondController.tabBarItem.imageInsets = UIEdgeInsets(top: 8, left: 0, bottom: -8, right: 0)
if something == true {
navFirstController.tabBarItem.image = UIImage.scale(image: UIImage(named: "image1")!, by: scale)
} else {
navFirstController.tabBarItem.image = UIImage.scale(image: UIImage(named: "image3")!, by: scale)
}
navFirstController.tabBarItem.imageInsets = UIEdgeInsets(top: 8, left: 0, bottom: -8, right: 0)
viewControllers = [navSecondController, navFirstController]
}
}
我尝试过:
1) viewControllers?.remove(at: 1)
setupItems()
开头
2) navFirstController.removeFromParent()
setupItems()
开头
3) self.viewWillLayoutSubviews()
在 setupItems()
末尾
4) self.view.setNeedsLayout()
, self.view.setNeedsDisplay()
在 setupItems()
末尾
最佳答案
我认为我们不需要再次创建 viewControllers 对象来更改选项卡栏图像。 只是我们需要从 viewControllers 数组中获取 viewController 对象并更改图像。
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
}
class SecondViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func btnClicked(_ sender: Any) {
//change image of tab bar item on button clicked
if let tabVC = self.tabBarController as? TabBarController {
tabVC.changeImage()
}
}
}
class TabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
setupItems()
}
func setupItems() {
let storyboard = UIStoryboard(name: "Main", bundle: Bundle.main)
let firstVC = storyboard.instantiateViewController(withIdentifier: "First")
let navFirstController = UINavigationController(rootViewController: firstVC)
navFirstController.tabBarItem.image = UIImage(named: "Image1")
let secondVC = storyboard.instantiateViewController(withIdentifier: "Second")
let navSecondController = UINavigationController(rootViewController: secondVC)
navSecondController.tabBarItem.image = UIImage(named: "Image2")
viewControllers = [navSecondController, navFirstController]
}
func changeImage() {
if let second = viewControllers?[1] as? UINavigationController {
second.tabBarItem.selectedImage = UIImage(named: "Image3")
second.tabBarItem.image = UIImage(named: "Image3")
}
}
}
注意如果您想更改选定的选项卡栏项目图像,请更改“selectedImage”值,否则更改“image”值。
关于ios - 按需重新加载 UITabBarController,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57681102/