交互式视图控制器从视图控制器转换，状态栏隐藏

Question

这是我的demo project。

我有两个视图控制器。主要的状态栏隐藏，而第二个没有。

我创建了一个自定义驱动的过渡动画，从控制器1转到控制器2。

当我在子视图控制器（橙色视图）上时，我通过从上到下平移来启动驱动过渡。拖动时，您可以看到状态栏正在返回。而UIButton＆＃34;你好＆＃34;也在移动。

我取消了过渡。然后我再次启动它，你可以看到状态栏也回来了，但这一次，我的按钮没有移动，它停留在同一个位置，好像状态栏仍然是隐藏的。

知道为什么一旦转换至少被取消一次就会出现这样的行为？

（我甚至没有谈论动画的奇怪之处，取消时会加倍（可能是模拟器的一个错误，因为它不会在我的iphone 6 9.1和我的iphone上做到这一点） 5 8.4。）

Answer 1

添加：import Foundation

然后添加一个插座：

class ViewController: UIViewController { @IBOutlet weak var topConstraint: NSLayoutConstraint! ... } 然后在视图消失时将值更改为0，然后在出现时将值更改为20：

override func viewWillAppear(animated: Bool) {
    topConstraint.constant = 20.0
}

override func viewWillDisappear(animated: Bool) {
    topConstraint.constant = 0.0
}

完整代码（请务必记住将约束连接到插座）：

import UIKit
import Foundation

class ViewController: UIViewController {

    @IBOutlet weak var topConstraint: NSLayoutConstraint!
    let controllerTransition = InteractiveControllerTransition(gestureType: .Pan)
    let controllerTransitionDelegate = ViewController2Transition()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        controllerTransition.delegate = controllerTransitionDelegate
        controllerTransition.edge = .Bottom


    }

    override func viewWillAppear(animated: Bool) {
        topConstraint.constant = 20.0
    }

    override func viewWillDisappear(animated: Bool) {
        topConstraint.constant = 0.0
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func unwindToViewController(sender: UIStoryboardSegue) { }

    override func prefersStatusBarHidden() -> Bool {
        return false
    }

    @IBAction func helloButtonAction(sender: UIButton) {
//      let storyBoard = UIStoryboard(name: "Main", bundle: nil)
//      let vc = storyBoard.instantiateViewControllerWithIdentifier("ViewController2") as! ViewController2
//      
//      vc.transitioningDelegate = controllerTransition
//      controllerTransition.toViewController = vc
//      
//      self.presentViewController(vc, animated: true, completion: nil)

        let storyBoard = UIStoryboard(name: "Main", bundle: nil)
//      let nvc = storyBoard.instantiateViewControllerWithIdentifier("NavigationViewController2") as! UINavigationController
//      let vc = nvc.topViewController as! ViewController2

        let vc = storyBoard.instantiateViewControllerWithIdentifier("ViewController2") as! ViewController2





//      nvc.transitioningDelegate = controllerTransition
        vc.transitioningDelegate = controllerTransition
        controllerTransition.toViewController = vc

//      self.presentViewController(nvc, animated: true, completion: nil)
        self.presentViewController(vc, animated: true, completion: nil)

    }

}