如何让自定义标签栏显示标签栏项目在 Xcode 中设置的选定图像？
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【中文标题】如何让自定义标签栏显示标签栏项目在 Xcode 中设置的选定图像？【英文标题】：How to get a custom tab bar to display a tab bar item's selected image set in Xcode? 【发布时间】：2017-03-13 02:05:25 【问题描述】：我创建了一个自定义标签栏，可以正确显示标签栏项目。当我选择一个选项卡/图标时，会显示选项卡栏项目的视图控制器，但图标不会更改为“选定图像”图标，即显示其视图控制器时图标不会更改。
我做错了什么？如何让图标更新为我在 IB 上设置为选定图像的图像？
这是我的一些代码：
class CustomTabBarController: UITabBarController, CustomTabBarDataSource, CustomTabBarDelegate
override func viewDidLoad()
super.viewDidLoad()
self.tabBar.isHidden = true
let customTabBar = CustomTabBar(frame: self.tabBar.frame)
customTabBar.datasource = self
customTabBar.delegate = self
customTabBar.setup()
self.view.addSubview(customTabBar)
// MARK: - CustomTabBarDataSource
func tabBarItemsInCustomTabBar(_ tabBarView: CustomTabBar) -> [UITabBarItem]
return tabBar.items!
// MARK: - CustomTabBarDelegate
func didSelectViewController(_ tabBarView: CustomTabBar, atIndex index: Int)
self.selectedIndex = index
class CustomTabBar: UIView
var tabBarItems: [UITabBarItem]!
var customTabBarItems: [CustomTabBarItem]!
var tabBarButtons: [UIButton]!
func setup()
tabBarItems = datasource.tabBarItemsInCustomTabBar(self)
customTabBarItems = []
tabBarButtons = []
let containers = createTabBarItemContainers()
createTabBarItems(containers)
func createTabBarItems(_ containers: [CGRect])
var index = 0
for item in tabBarItems
let container = containers[index]
let customTabBarItem = CustomTabBarItem(frame: container)
customTabBarItem.setup(item)
self.addSubview(customTabBarItem)
customTabBarItems.append(customTabBarItem)
let button = UIButton(frame: CGRect(x: 0, y: 0, width: container.width, height: container.height))
button.addTarget(self, action: #selector(CustomTabBar.barItemTapped(_:)), for: UIControlEvents.touchUpInside)
customTabBarItem.addSubview(button)
tabBarButtons.append(button)
index += 1
func barItemTapped(_ sender : UIButton)
let index = tabBarButtons.index(of: sender)!
delegate.didSelectViewController(self, atIndex: index)
【问题讨论】：
图片是否存在于 Assets.xcassets 中？ 而且，您将CustomTabBar 类设置为UIView 的子类而不是UITabBar 有什么原因吗？
【参考方案1】：
改变
class CustomTabBar: UIView
到：
class CustomTabBar: UITabBar
然后您的自定义标签栏将像一个标签栏！
【讨论】：
【参考方案2】：嗯，我有类似的功能，并像这样用 UITabBarController 实现。
enum TabType:Int
case viewController1 = 0
case viewController2 = 1
case viewController3 = 2
class CustomTabbarVC: UITabBarController
override func viewDidLoad()
super.viewDidLoad()
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
convenience init(userType : UserType)
self.init()
addViewControllers()
setupOnInit()
let tabBar = self.tabBar
tabBar.selectionIndicatorImage = UIImage().createSelectionIndicator(UIColor(red: 22/255, green: 52/255, blue: 89/255, alpha: 1.0), size: CGSize(width: tabBar.frame.width/CGFloat(tabBar.items!.count), height: tabBar.frame.height), lineWidth: 3.0)
func setupOnInit()
delegate = self
tabBar.barStyle = UIBarStyle.black
tabBar.isTranslucent = false
func addViewControllers()
// We will add 3 controllers
let viewController1 = viewController1(nibName: “viewController1”, bundle: nil)
let viewController2 = viewController2(nibName: “viewController2”, bundle: nil)
let viewController3 = viewController3(nibName: “viewController3”, bundle: nil)
let viewController1Navigation = UINavigationController(rootViewController: viewController1)
viewController1Navigation.tabBarItem = getTabbarItem(.viewController1)
viewController1Navigation.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0)
let viewController2Navigation = UINavigationController(rootViewController: viewController2)
viewController2Navigation.tabBarItem = getTabbarItem(.viewController2)
viewController2Navigation.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0)
let viewController3Navigation = UINavigationController(rootViewController: viewController3)
viewController3Navigation.tabBarItem = getTabbarItem(.viewController3)
viewController3Navigation.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0)
viewControllers = [viewController1Navigation,viewController2Navigation,viewController3Navigation]
func getTabbarItem(_ tabType:TabType)->UITabBarItem
// Fetch tab bar item and set image according to it.
var image = String()
var selectedImage = String()
if tabType == .viewController1
image = “img_viewController1_tab_nonSelected”
selectedImage = “img_viewController1_tab_Selected”
else if tabType == .viewController2
image = “img_viewController2_tab_nonSelected”
selectedImage = “img_viewController2_tab_Selected”
else if tabType == .viewController3
image = “img_viewController3_tab_nonSelected”
selectedImage = “img_viewController3_tab_Selected”
else
print("Unknown tab type")
if let imageName:String = image,let selectedImageName:String = selectedImage
return UITabBarItem(title: nil, image: UIImage(named: imageName)?.withRenderingMode(.alwaysOriginal), selectedImage: UIImage(named: selectedImageName)?.withRenderingMode(.alwaysOriginal))
else
return UITabBarItem()
extension UIImage
func createSelectionIndicator(_ color: UIColor, size: CGSize, lineWidth: CGFloat) -> UIImage
UIGraphicsBeginImageContextWithOptions(size, false, 0)
color.setFill()
UIRectFill(CGRect(x: 0, y: size.height - lineWidth, width: size.width, height: lineWidth))
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image!
如何在 App delegate 中实现
class AppDelegate: UIResponder, UIApplicationDelegate
var window: UIWindow?
var customTabbarVC: CustomTabbarVC?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool
window = UIWindow(frame: UIScreen.main.bounds)
customTabbarVC = customTabbarVC() // It will invoke init methods of customtabbarvc
window?.rootViewController = customTabbarVC // Here your tab bar controller will setup
return true
// Other APP DELEGATE METHODS
如果您有任何问题，请告诉我..
【讨论】：
【参考方案3】：要在单击按钮后更改自定义标签栏按钮中的图像，您需要编写代码以更改以下函数中的图像
func barItemTapped(_ sender : UIButton)
类似
func barItemTapped(_ sender : UIButton)
if sender.tag == 1
tabBarButtons.setImage(UIImage(named:"FirstImage.png"), forState: .Normal)
else
tabBarButtons.setImage(UIImage(named:"SecImage.png"), forState: .Normal)
【讨论】：
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