APP进入后台后才会释放内存 _内存

幼敏悟过人，读书辄成诵。这篇文章主要讲述APP进入后台后才会释放内存相关的知识，希望能为你提供帮助。
【APP进入后台后才会释放内存】我正在开发一个带侧边菜单的应用程序，在ContainController中使用两个ViewController。当关闭侧面菜单ViewController（调用deinit方法）后，内存就不会被释放（大概是23 MiB），直到应用程序进入后台。在Xcode 9中构建的“Leaks”工具表示根本没有内存泄漏......任何人都可以告诉我什么是错的？非常感谢提前！

import UIKit import CoreDataenum MenuState { case Collapsed case Expanding case Expanded }class ContainerViewController: UIViewController {weak var managedObjectContext: NSManagedObjectContext!weak var mainViewController: MasterViewController!weak var menuViewController: MenuViewController?var currentState = MenuState.Collapsed { didSet { let shouldShowShadow = currentState != .Collapsed showShadowForMainViewController(shouldShowShadow: shouldShowShadow) } }override func viewDidLoad() { super.viewDidLoad()mainViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "mainView") as! MasterViewController view.addSubview(mainViewController.view)DispatchQueue.global(qos: .userInteractive).async { self.mainViewController.managedObjectContext = self.managedObjectContext self.addChildViewController(self.mainViewController) self.mainViewController.didMove(toParentViewController: self) }let panGestureRecognizer = UIPanGestureRecognizer(target: self, action:#selector(self.handlePanGesture(_:))) self.mainViewController.view.addGestureRecognizer(panGestureRecognizer)let tapGestureRecognizer = UITapGestureRecognizer(target: self, action:#selector(self.handleTapGesture)) self.mainViewController.view.addGestureRecognizer(tapGestureRecognizer) }@objc func handlePanGesture(_ recognizer: UIPanGestureRecognizer) {switch(recognizer.state) {case .began:let dragFromLeftToRight = (recognizer.velocity(in: view).x > 0) if (currentState == .Collapsed & & dragFromLeftToRight) { currentState = .Expanding addMenuViewController() }case .changed:let positionX = recognizer.view!.frame.origin.x + recognizer.translation(in: view).x recognizer.view!.frame.origin.x = positionX < 0 ? 0 : positionXlet boundX = mainViewController.view.frame.width - menuViewExpandedOffset if positionX > 0 { recognizer.view!.frame.origin.x = positionX > boundX ? boundX : positionX } recognizer.setTranslation(.zero, in: view)case .ended:let boundX = mainViewController.view.frame.width - menuViewExpandedOffset let hasMovedhanHalfway = (recognizer.view!.frame.origin.x > boundX * 0.3) animateMainView(shouldExpand: hasMovedhanHalfway)default: break } }@objc func handleTapGesture() { if currentState == .Expanded {animateMainView(shouldExpand: false) } }//ADD MENUVC func addMenuViewController() { if (menuViewController == nil) { menuViewController = UIStoryboard(name: "Main", bundle: nil) .instantiateViewController(withIdentifier: "menuView") as? MenuViewControllerview.insertSubview(menuViewController!.view, at: 0)addChildViewController(menuViewController!) menuViewController!.didMove(toParentViewController: self) } }let menuViewExpandedOffset: CGFloat = 480func animateMainView(shouldExpand: Bool) {if (shouldExpand) {currentState = .Expanded animateMainViewXPosition(targetPosition: mainViewController.view.frame.width - menuViewExpandedOffset) }else { animateMainViewXPosition(targetPosition: 0) { finished inself.currentState = .Collapsedself.menuViewController?.view.removeFromSuperview() self.menuViewController?.removeFromParentViewController() self.menuViewController = nil } } }func animateMainViewXPosition(targetPosition: CGFloat, completion: ((Bool) -> Void)! = nil) {UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1.0, initialSpringVelocity: 0, options: .curveEaseOut, animations: { self.mainViewController.view.frame.origin.x = targetPosition }, completion: completion) }func showShadowForMainViewController(shouldShowShadow: Bool) { if (shouldShowShadow) { mainViewController.cameraBGimage.layer.shadowOpacity = 0.6 mainViewController.cameraBGimage.layer.shadowOffset = CGSize(width: 0, height: 1) } else { mainViewController.cameraBGimage.layer.shadowOpacity = 0.0 } }}

答案可以说你的应用程序没有任何问题。 ios系统将以其认为最佳的方式管理内存。
如果你的对象应该被取消分配，那么你没事。如果您想更好地了解视图何时被取消分配，您可以随时使用Allocations的de Instruments工具并按应用程序的名称对其进行过滤。