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我正在构建一个 TVML/TVJS Apple TV 应用程序，但我需要能够通过播放器获得一些本机功能，因此我正在使用evaluateAppJavaScriptInContext创建一个 JavaScript 函数，该函数将在调用时将自定义视图控制器推送到屏幕上。问题是它会在控制台中引起警告：

此应用程序正在从后台线程修改自动布局引擎，这可能导致引擎损坏和奇怪的崩溃。这将在未来的版本中导致异常。

代码如下所示：

import TVMLKit
import AVKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, TVApplicationControllerDelegate {

var window: UIWindow?

var appController: TVApplicationController?
var workoutViewController = WorkoutViewController()
static let TVBaseURL = "http://localhost:3000/"
static let TVBootURL = "\(AppDelegate.TVBaseURL)assets/tv.js"

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    window = UIWindow(frame: UIScreen.mainScreen().bounds)

    // 1
    let appControllerContext = TVApplicationControllerContext()

    // 2
    guard let javaScriptURL = NSURL(string: AppDelegate.TVBootURL) else {
        fatalError("unable to create NSURL")
    }
    appControllerContext.javaScriptApplicationURL = javaScriptURL
    appControllerContext.launchOptions["BASEURL"] = AppDelegate.TVBaseURL

    // 3
    appController = TVApplicationController(context: appControllerContext, window: window, delegate: self)

    do {
        guard let audioURL = NSURL(string: self.workoutViewController.audioURL) else {
            fatalError("unable to create NSURL")
        }

        let audioPlayer = try AVAudioPlayer(contentsOfURL: audioURL)

        if (audioPlayer.prepareToPlay()) {
            audioPlayer.play()
        }
    } catch {
        print("Error: \(error)")
    }

    return true
}

func appController(appController: TVApplicationController, evaluateAppJavaScriptInContext jsContext: JSContext) {
    let presentWorkoutViewController : @convention(block) (String) -> Void = { (string : String) -> Void in

        self.workoutViewController.jsonString = string

         // dispatch_async(dispatch_get_main_queue(), {
            self.appController?.navigationController.pushViewController(self.workoutViewController, animated: true)
         // })

    }
    jsContext.setObject(unsafeBitCast(presentWorkoutViewController, AnyObject.self), forKeyedSubscript: "presentWorkoutViewController")
}
}

我尝试将其包装在 a 中dispatch_async并修复了错误，但是当我尝试将本机视图控制器推回视图时，它仍然包含其旧内容，而不是我试图显示的新内容。

看起来像这样：

dispatch_async(dispatch_get_main_queue(), {
    self.appController?.navigationController.pushViewController(self.workoutViewController, animated: true)
})

提前致谢！

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