如何通过导航栏按钮访问选项卡栏项

Question

我创建了一个CustomTabBarController类，它具有5个效果很好的按钮。

每个按钮触发一个单独的视图控制器。

示例：home按钮触发homeViewController并将其完美显示在屏幕上。

在homeViewController ，我使用以下代码创建了一个右栏按钮项：

let homeButton = UIBarButtonItem(image: UIImage(named: "HomeButton"), style: .plain, target: self, action:#selector(homeViewController.goToHomeVC)

self.navigationItem.rightBarButtonItem  = homeButton

    func goToHomeVC(sender: UIButton) {
         // Go to home page (tab bar index 0)
}

我如何实现我的tappedHome函数，以便它可以访问选项卡栏项（主页），从而触发homeViewController并将其显示在屏幕上？

Answer 1

基本上，这不是实际的UITabBarController因此， 您必须手动维护推送和弹出。

这里的push和pop代码将帮助您在五个视图控制器类之间切换。

func pushIfRequired(className:AnyClass) {

    if (UIViewController.self != className) {
        print("Your pushed class must be child of UIViewController")
        return
    }
    let storyboard : UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    var isPopDone = false
    let mainNavigation = UIApplication.shared.delegate?.window??.rootViewController as? UINavigationController
    let viewControllers = mainNavigation!.viewControllers
    for vc in viewControllers {
        if (type(of: vc) == className) {
            mainNavigation?.popToViewController(vc, animated: true)
            isPopDone =  true
            break
        }
    }
    if isPopDone == false{
        let instanceSignUp = storyboard.instantiateViewController(withIdentifier: NSStringFromClass(className)) // Identifier must be same name as class
        mainNavigation?.pushViewController(instanceSignUp, animated: true)
    }
}

用途

pushIfRequired(className: FirstTabVC.self)

Answer 2

如果您不介意检查父项以获取CustomTabBarController，

func navButtonPressedAction() {
    guard let tabVC = self.parent?.parent as? UITabBarController else { return }
    tabVC.selectedIndex = 2 //Index of the tab bar item here
}