ios - 在 Swift 中从另一个 ViewController 访问变量

Question

我有以下 ViewController:

class PageContentViewController: UIViewController {

    var pageIndex: Int

}

如何从另一个 ViewController 访问 pageIndex？

我需要在这个函数中访问pageIndex:

func pageViewController(pageViewController: UIPageViewController!, viewControllerBeforeViewController viewController: UIViewController!) -> UIViewController! {

    //var index: Int
    //index = ?

    NSUInteger index = ((PageContentViewController*) viewController).pageIndex; // in Swift?

    if ((index == 0) || (index == NSNotFound)) {
        return nil;
    }

    index--;

    return [self viewControllerAtIndex:index]; // in Swift?
}

Answer 1

默认情况下，swift 中的所有内容都是公开的，因此如果您声明如下内容:

class SomeViewController: UIViewController {
    var someVariable: SomeType = someValue

    init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    }
}

只要您拥有它的实例，您就可以访问它:

var myCustomViewController: SomeViewController = SomeViewController(nibName: nil, bundle: nil)
var getThatValue = myCustomViewController.someVariable