ios - 模态转换后释放 SKScene

Question

我一直在使用 swift 在 sprite kit 中创建游戏，但遇到了问题。我有两个 View Controller ，每个都有一个场景，一个以模态方式过渡到另一个。这一切都在第一轮完美运行，但是当我返回到第一个 View Controller 然后再次转到第二个时，我使用了双倍的内存。这给我的印象是没有任何东西被释放，但是每次我转换到场景时对象都会被重新分配。我在仪器中运行该应用程序并得到相同的结果。在下图中，我从一个场景移动到下一个场景，然后又回到第一个场景，但它似乎重新分配了第一个场景，但没有清除任何内存。由于现在未使用 dealloc 方法，我不知道如何解决这个问题。我会将代码发布到下面的第一个 View Controller ，以便您可以查看它。非常感谢。

import UIKit
import SpriteKit

class SelectionViewController: UIViewController {

var selectionScene:SelectionScene?
var currentRocketName = ""

@IBOutlet var playButton: UIButton

override func viewDidLoad() {
    super.viewDidLoad()

    if let selectionScene = SelectionScene.unarchiveFromFile("SelectionScene") as? SelectionScene {

        // Configure the view.
        let skView = self.view as SKView
        skView.showsFPS = true
        skView.showsNodeCount = true
        skView.multipleTouchEnabled = false

        /* Sprite Kit applies additional optimizations to improve rendering performance */
        skView.ignoresSiblingOrder = true

        /* Set the scale mode to scale to fit the window */
        selectionScene.scaleMode = .ResizeFill
        selectionScene.viewController = self

        skView.presentScene(selectionScene)

        NSNotificationCenter.defaultCenter().addObserver(selectionScene, selector: "spinnerChanged", name: "spinnerValueChanged", object: nil)
        NSNotificationCenter.defaultCenter().addObserver(selectionScene, selector: "productBought", name: "ProductBought", object: nil);
        NSNotificationCenter.defaultCenter().addObserver(selectionScene, selector: "manageErrorInPurchase", name: "ErrorOccured", object: nil)

    }
}

override func shouldAutorotate() -> Bool {
    return true
}

override func viewDidAppear(animated: Bool)  {
}

@IBAction func playButtonPressed(sender: UIButton) {
    self.performSegueWithIdentifier("moveToGame", sender: nil)
}

override func prefersStatusBarHidden() -> Bool {
    return true
}

override func supportedInterfaceOrientations() -> Int {
    if UIDevice.currentDevice().userInterfaceIdiom == .Phone {
        return Int(UIInterfaceOrientationMask.AllButUpsideDown.toRaw())
    } else {
        return Int(UIInterfaceOrientationMask.All.toRaw())
    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Release any cached data, images, etc that aren't in use.
}

override func viewDidUnload() {
    NSNotificationCenter.defaultCenter().removeObserver(selectionScene)
}

override func viewDidDisappear(animated: Bool) {
    NSNotificationCenter.defaultCenter().removeObserver(selectionScene)
}

override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
    if segue.identifier == "moveToGame" {
        let destController = segue.destinationViewController as GameViewController
        destController.rocketTexture = SKTexture(imageNamed: self.currentRocketName)
    }
}

}

selectionScene 和 currentRocketName 一旦加载到 View 中就会被传递给 viewController

Answer 1

我还不熟悉 Swift，所以我会用 Objective-C 给你例子。

为 skView 创建一个 IBOutlet。当您要呈现另一个 ViewController 时，从它的 super View 中删除 skView 并将其清除:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Need to deallocate GameScene (if game is not paused)
    [self.skView removeFromSuperview];
    self.skView = nil;
    ....
}

当加载 ViewController 时，不要忘记将 skView 添加回 ViewController 的 View :

if (!self.skView.window) {
    [self.view addSubview:self.skView];
}

要轻松检查 SKScene 是否被释放，请将此方法添加到其中:

- (void)dealloc {
    NSLog(@"GAME SCENE DEALLOCATED");
}