UIViewController.storyboard只能在主线程中使用-新的错误我不知道如何修复？

DispatchQueue.main.async {
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let viewController = storyboard.instantiateViewController(withIdentifier: "ViewControllerIdentifier")
    // 在主线程中继续处理viewController
}

var storyboard: UIStoryboard?

DispatchQueue.main.async {
    storyboard = UIStoryboard(name: "Main", bundle: nil)
}

DispatchQueue.global().async {
    // 在非主线程中使用已加载的storyboard
    let viewController = storyboard?.instantiateViewController(withIdentifier: "ViewControllerIdentifier")
    // 继续处理viewController
}