如何在NSApplicationDelegate上加载NSViewController

Question

我试图在appDelegate类上加载ViewController。像这样：

class AppDelegate: NSObject, NSApplicationDelegate {

  @IBOutlet weak var window: NSWindow!

  var viewController = HomeViewController()

  func applicationDidFinishLaunching(aNotification: NSNotification) {
     self.window.backgroundColor = NSColor(rgba: "#02303A")
     self.viewController.view.frame = CGRectMake(0, 0, CGRectGetWidth(self.window.frame), CGRectGetHeight(self.window.frame))
     self.window.contentView?.addSubview(self.viewController.view)
  }

}

我的视图控制器非常简单，只需：

import PureLayout

class HomeViewController : NSViewController {

  let search : NSSearchField = {
    let search = NSSearchField.newAutoLayoutView()
    return search
  }()

  override func loadView() {
    super.loadView()
    self.view.layer?.backgroundColor = NSColor.blackColor().CGColor
    self.view.addSubview(search)
  }

}

但是当我编译项目时，日志返回：

包含完整源代码的存储库：Github

任何人都知道可以做什么？我在我的iOS项目上这样做，它工作正常。