Deinit 永远不会被调用，内存问题

Question

所以我的 deinit 函数从未被调用过，我已经在寻找答案，但是 none 对我有用。 viewcontroller 由于内存问题不断崩溃。感谢您的帮助！

这是我的代码：

@IBOutlet weak var scnView: SCNView!
@IBOutlet weak var artInfoView: UIView!
@IBOutlet weak var mainTitleLbl: UILabel!
@IBOutlet weak var textView: UITextView!
@IBOutlet weak var timeLbl: UILabel!
@IBOutlet weak var stackView: UIStackView!
@IBOutlet weak var artistImg: RoundImage!
@IBOutlet weak var artistNameLbl: UILabel!
@IBOutlet weak var artistView: UIView!

var artRoomScene = ArtRoomScene(create: true)
var artImage = UIImage()
var artInfo: [Any] = []
var posts = [Art]()
var post: Art!
var user: Users!
var showInfo: Bool = false
var showSimilar: Bool = false
let alert = Alerts()

override func viewDidLoad() {
    super.viewDidLoad()

    scnView = self.scnView!
    let scene = artRoomScene
    scnView.scene = scene
    scnView.autoenablesDefaultLighting = true
    scnView.isJitteringEnabled = true
    scnView.backgroundColor = UIColor.white


    if let info = self.artInfo[1] as? Art {
        let image = self.artInfo[0] as? UIImage
        let height = (image?.size.height)! / 900
        let width = (image?.size.width)! / 900
        self.artRoomScene.setup(artInfo: image, height: height, width: width)
        self.mainTitleLbl.text = info.title

        let date = info.postDate/1000
        let foo: TimeInterval = TimeInterval(date)
        let theDate = NSDate(timeIntervalSince1970: foo)
        let time = timeAgoSinceDate(date: theDate as Date, numericDates: true)
        self.timeLbl.text = "\(time)"
        self.textView.text = "\(info.artHeight)'H x \(info.artWidth)'W - \(info.price)$ / month - \(info.type) \n \(info.description)."

        DataService.instance.REF_USERS.child("\(info.userUid)").observe(.value, with: { (snapshot) in
            if let postDict = snapshot.value as? Dictionary<String, AnyObject> {
                let key = snapshot.key
                self.user = Users(key: key, artistData: postDict)

                if let user = self.user {
                    self.artistNameLbl.text = user.name
                    self.artistImg.sd_setImage(with: URL(string: "\(user.profilePicUrl!)") , placeholderImage: UIImage(named:"Placeholder") , options: .continueInBackground)
                }
            }
        })
    }
 }


deinit {
    print("viewcontroller is being deallocated")
}

Answer 1

您可能需要在提供给数据服务的闭包中使用对 self 的弱引用或无主引用。或者，您可能想要查看该代码并确保它在您期望的时候释放它对该闭包的引用。给定 observe 动词，我希望它无限期地持有对这个闭包的引用。所以我推荐这个：

在闭包中使用对 self 的弱引用
在你的 dealloc 中，或者像 viewWillDisappear 这样的其他时间，告诉数据服务你希望 unsubscribe/stop 观察。这很重要，这样您就不会遇到相反的问题：闭包中的悬垂指针。

对于 #1，关键部分就在你的闭包中，Swift 有一种指定的方式来声明 self 应该是一个弱指针：

DataService.instance.REF_USERS.child("\(info.userUid)").observe(.value, with: { (snapshot) in

变成

DataService.instance.REF_USERS.child("\(info.userUid)").observe(.value, with: { [weak self] (snapshot) in

请注意，您也可以使用 [unowned self]，但您会断言您知道当此块执行时 self 永远不会 non-nil。我不认为当你传递给第 3 方时你会知道这一点。所以使用 [weak self] 然后你必须将 self 视为可选的，这对这种情况非常有用！

Answer 2

这将调用你的 deinit

weak var weakSelf = self
DataService.instance.REF_USERS.child("\(info.userUid)").observe(.value, with: { (snapshot) in
     if let postDict = snapshot.value as? Dictionary<String, AnyObject>, let strongSelf = weakSelf {
        let key = snapshot.key
        strongSelf.user = Users(key: key, artistData: postDict)

        if let user = strongSelf.user {
            strongSelf.artistNameLbl.text = user.name
                strongSelf.artistImg.sd_setImage(with: URL(string: "\(user.profilePicUrl!)") , placeholderImage: UIImage(named:"Placeholder") , options: .continueInBackground)
        }
    }
})

Deinit 永远不会被调用，内存问题

Deinit never gets called, Memory issue

ios

scenekit

swift