swift - GameViewController 中的完成处理程序崩溃

Question

想在游戏开始前预加载 textureAtlases，所以我决定将场景启动代码放入完成处理程序中，但由于某些原因应用程序崩溃了。这是我的代码:

import UIKit
import SpriteKit
import GameplayKit

class GameViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let gpuAtlas = SKTextureAtlas(named: "GP")
        let ppAtlas = SKTextureAtlas(named: "PP")

        SKTextureAtlas.preloadTextureAtlases([gpuAtlas, ppAtlas]) {

            if let view = self.view as? SKView {

                let scene = GameScene(size: self.view.bounds.size)
                // Set the scale mode to scale to fit the window
                scene.scaleMode = .aspectFill

                // Present the scene
                view.presentScene(scene)


                view.ignoresSiblingOrder = true

                view.showsFPS = true
                view.showsNodeCount = true
            }
        } 
    }

    override var shouldAutorotate: Bool {
        return true
    }

    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        return .portrait
    }

    override var prefersStatusBarHidden: Bool {
        return true
    }
}

如果我删除预加载纹理图集方法，一切都会照常工作，但我希望预加载纹理有一个变化，以摆脱由于在缓存中加载纹理而导致的第一个关键帧卡住。

错误:

fatal error: unexpectedly found nil while unwrapping an Optional value

更新:它在方法 didSimulatePhysics 中的 GameScene.swift 文件上崩溃。

伙计们，我做错了什么？

Answer 1

试试这个(使用 main thread 来操作 View 和 weak self):

SKTextureAtlas.preloadTextureAtlases([gpuAtlas, ppAtlas]) { [weak self] in
    guard let gameView = self?.view as? SKView else { return }
    DispatchQueue.main.async {
        let scene = GameScene(size: gameView.bounds.size)
        // Set the scale mode to scale to fit the window
        scene.scaleMode = .aspectFill
        // Present the scene
        gameView.presentScene(scene)
        gameView.ignoresSiblingOrder = true
        gameView.showsFPS = true
        gameView.showsNodeCount = true
    }
}

你检查过 scene 是否是可选的吗？如果是这样:

guard let scene = GameScene(size: gameView.bounds.size) else { return }