为什么VC的view init from xib的框架不是主屏幕的大小?

我有故事板和XIB VCs。只要体验一下:

UIScreen.main().bounds .

更深入地说,当从情节提要初始化时,视图似乎获得了属性 view.window != nil window == nil . 也许这就是奇怪尺寸的原因。

我试图手动设置如下: vc.view.frame = UIScreen.main.bounds ,并且有效。然而,这也会触发 viewDidLoad 在那里,我对我的内容进行了一些设置,而当时的IBOutlet还没有加载,每个设置都是错误的!

因此,提出了一个额外的问题:如何在从XIB初始化后强制加载IBMoutlet?

import MFSideMenu

...
// initialize from somewhere else and push it to menu.containerVC.centerVC
let vc = MyVC.init(nibName:MyVC.className, bundle:self.nibBundle)
...

// This method is from subclass of MFSideMenuVC
func pushCenterVC(vc: UIViewController!) {

    // This cause the setup in vc.viewDidLoad go wrong
    // If side menu is load for the first time, it doesn't have its window yet.
    if self.view.window != nil {
        vc.view.frame = self.view.window.bounds
    }

    self.menuContainerViewController.centerViewController = vc

    // If I put it here, MFSideMenu will create an ugly shadow because of wrong initilize frame size.
    // if self.view.window != nil {
    //     vc.view.frame = self.view.window.bounds
    // }
}