我有三个视图控制器嵌入导航控制器.我想从VC1到VC3,以便在VC3中,导航项的后退按钮可以将用户定向到VC2而不是VC1.我认为这应该是通过在VC3创建之后将VC2添加到VC1和VC3之间的导航堆栈或通过跳过第二个View Controller来完成的.
我试过这个：
override func prepareForSegue(segue: UIStoryboardSegue,sender: AnyObject?) {
if let identifier = segue.identifier {
switch identifier {
case "JumpToThirdVCSegue":
if let secondvc = segue.destinationViewController as? SecondViewController {
secondvc.performSegueWithIdentifier("ThirdVCSegue",sender: self)
}
default: break
}
}
}
但我不能让它工作.当View Controller尚未打开时,是否可能执行segue？
解决方法
这样的事情应该有效：
self.navigationController?.pushViewController(viewController2,animated: true)
self.navigationController?.pushViewController(viewController3,animated: true)
编辑：
如果您希望推送第二个视图控制器,而不会被用户注意到,则在按下第三个视图控制器之后,您需要将其添加到导航控制器.这可以通过实现UINavigationControllerDelegate来实现.您可以将第二个视图控制器存储在变量中,并使用委托方法将其插入到导航控制器层次结构中.您的主视图控制器将如下所示：
class MyViewController: UIViewController,UINavigationControllerDelegate {
var viewControllerToInsertBelow : UIViewController?
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.delegate = self
}
func pushTwoViewControllers() {
if let viewController2 = self.storyboard?.instantiateViewControllerWithIdentifier("id1"),let viewController3 = self.storyboard?.instantiateViewControllerWithIdentifier("id2") { //change this to your identifiers
self.viewControllerToInsertBelow = viewController2
self.navigationController?.pushViewController(viewController3,animated: true)
}
}
//MARK: - UINavigationControllerDelegate
func navigationController(navigationController: UINavigationController,didShowViewController viewController: UIViewController,animated: Bool) {
if let vc = viewControllerToInsertBelow {
viewControllerToInsertBelow = nil
let index = navigationController.viewControllers.indexOf(viewController)!
navigationController.viewControllers.insert(vc,atIndex: index)
}
}
}
