Question

我在我的UIViewController中声明了这个插座并链接到故事板：

@IBOutlet var pennyView: UIView!

我在loadView中加载了一个PageView控制器并在按钮上设置了一个选项：

   override func loadView() {
    super.loadView()

    //Add PageViewController
    pageViewController = UIPageViewController(transitionStyle: UIPageViewControllerTransitionStyle.Scroll, navigationOrientation:
        UIPageViewControllerNavigationOrientation.Horizontal, options: nil)
    let child = viewControllerAtIndex(0)
    pageViewController!.setViewControllers([child!], direction: UIPageViewControllerNavigationDirection.Forward, animated: false, completion: nil)
    pageViewController!.dataSource = self
    self.addChildViewController(pageViewController!)
    self.view.addSubview(pageViewController!.view)

    //Add Buttom
    button.backgroundColor = UIColor.LightPurple(1)

    let pageViewcontrollerView = pageViewController!.view
    pageViewcontrollerView.setTranslatesAutoresizingMaskIntoConstraints(false)
    self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[pageViewcontrollerView][button]", options: nil, metrics: nil, views: ["pageViewcontrollerView":pageViewcontrollerView, "button":button]))
    self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[pageViewcontrollerView]|", options: nil, metrics: nil, views: ["pageViewcontrollerView":pageViewcontrollerView, "button":button]))

}

这一切都在iOS8模拟器中花花公子。但是我得到了一个＆＃34;致命错误：在iOS7.1上运行时解开一个可选值＆＃34; 引用此调用时意外发现nil

        button.backgroundColor = UIColor.LightPurple(1)

是什么给出了？

Answer 1

iOS 7.1和iOS 8.0之间最棘手问题的解决方案非常简单：

iOS模拟器＆gt;重置内容和设置

现在完美无缺，没有任何其他变化。疯狂。

从iOS 7中的loadView（）引用的@IBOutlet的Swift展开错误，但在iOS 8中有效

1 个答案: