Swift playground:获取ViewController来调用presentViewController

我想在Playground玩UIAlertController.是否有可能从XCPlaygroundPage获取ViewController - 能够调用presentViewController？

您可以设置实时查看到你的窗口后提出,以避免该警告.

import UIKit
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true
let window = UIWindow()
let viewController = UIViewController()
window.rootViewController = viewController
window.makeKeyAndVisible()

let alert = UIAlertController(title: "title here", message: "message here", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "action here", style: .default, handler: nil))
viewController.present(alert, animated: true, completion: nil)
PlaygroundPage.current.liveView = window

结果: