private let DBItemCellIdentifier = "ItemCellIdentifier"
private let DBItemSegueIdentifier = "ItemSegueIdentifier"
class DBItemsViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, DBItemTableViewCellDelegate {
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var previousButton: UIButton!
@IBOutlet weak var nextButton: UIButton!
@IBOutlet weak var categoryNameLabel: UILabel!
private var elements = [Any]()
private var currentItemIndex = 0
private var isFetching = false
private weak var currentCategory: DBCategory? {
didSet {
updateView()
}
}
var categories = [DBCategory]()
var currentCategoryIndex = 0
//MARK: - Class Methods
//MARK: - Initialization
override func viewDidLoad() {
super.viewDidLoad()
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 100.0
tableView.tableFooterView = UIView(frame: CGRectZero)
setupUserAndCartButtons()
fetchItems()
}
deinit {
print("deinit")
}
//MARK: - Actions
@IBAction func nextButtonTapped(sender: UIButton) {
currentCategoryIndex = min(currentCategoryIndex + 1, categories.count - 1)
fetchItems()
}
@IBAction func previousButtonTapped(sender: UIButton) {
currentCategoryIndex = max(currentCategoryIndex - 1, 0)
fetchItems()
}
//MARK: - Private
private func fetchItems() {
tableView.alpha = 0
currentCategory = nil
if !categories.isEmpty && !isFetching {
let category = categories[currentCategoryIndex]
currentCategory = DBCategory.findCategoryWithIdentifier(category.identifier)
if currentCategory == nil {
SVProgressHUD.show()
}
isFetching = true
DBNetworkClient.sharedClient().itemsForCategory(category, completionBlock: { error in
defer {
self.isFetching = false
SVProgressHUD.dismiss()
UIAlertController.showAlertFromError(error)
}
self.currentCategory = DBCategory.findCategoryWithIdentifier(category.identifier)
})
}
}
private func updateView() {
let category = categories[currentCategoryIndex]
title = category.menu.location.name
categoryNameLabel.text = category.name
previousButton.hidden = currentCategoryIndex == 0 ? true : false
nextButton.hidden = currentCategoryIndex == categories.count - 1 ? true : false
prepareElements()
tableView.reloadData()
UIView.animateWithDuration(0.5, animations: {
self.tableView.alpha = 1
})
}
private func prepareElements() {
elements.removeAll(keepCapacity: false)
if let items = currentCategory?.items {
for item in items {
elements.append(item)
}
}
if let sets = currentCategory?.sets {
for set in sets {
elements.append(set)
}
}
elements.sortInPlace {
let left = ($0 as? DBSet)?.position ?? ($0 as? DBItem)?.position
let right = ($1 as? DBSet)?.position ?? ($1 as? DBItem)?.position
return left < right
}
}
//MARK: - Overridden
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let element = elements[currentItemIndex]
if segue.identifier == DBItemSegueIdentifier {
let itemViewController = segue.destinationViewController as! DBItemViewController
itemViewController.prepareWithElement(element)
}
}
//MARK: - UITableViewDataSource
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 0 //when I change to elements.count, deinit is not called
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(DBItemCellIdentifier, forIndexPath: indexPath) as! DBItemTableViewCell
let element = elements[indexPath.row]
if let item = element as? DBItem {
cell.configureCellWithItem(item)
} else if let set = element as? DBSet {
cell.configureCellWithSet(set)
}
cell.delegate = self
return cell
}
//MARK: - UITableViewDelegate
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
currentItemIndex = indexPath.row
performSegueWithIdentifier(DBItemSegueIdentifier, sender: tableView.cellForRowAtIndexPath(indexPath))
}
//MARK: - DBItemTableViewCellDelegate
func itemTableViewCell(cell: DBItemTableViewCell, willPresentSetGroupsViewControllerForSet set: DBSet) {
presentSetOrderControllerWithOrder(DBSetOrder(set: set))
}
func itemTableViewCell(cell: DBItemTableViewCell, willPresentItemMealSizesViewControllerForItem item: DBItem) {
presentItemOrderControllerWithOrder(DBItemOrder(item: item))
}
}
为什么我的deinit没有被调用。一旦我能够做到这一点，我将提供 100 赏金，并奖励那个帮助我解决这个问题的人......即使解决了问题，我也会提供奖励
非常重要的信息：
此代码调用 deinit。这是工作。因为行数是0.但我需要有elements.count。当我更改为此时，不会调用deinit。
修改
func itemsForCategory(category: DBCategory, completionBlock: DBErrorHandler) {
let query = "locations/" + category.menu.location.identifier + "/categories/" + category.identifier
GET(query, parameters: nil, success: { operation, response in
if let error = NSError(response: response) {
completionBlock(error)
} else {
self.coreDataAssistant.parseAndSaveItemsToPersistentStore(response as? NSDictionary, completionBlock: { error in
completionBlock(error)
})
}
}) { operation, error in
let responseError = NSError(response: operation.responseObject)
completionBlock(responseError ?? error)
}
}
答案 0 :(得分：38)
您将self指定为表格查看单元格的委托：
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(DBItemCellIdentifier, forIndexPath: indexPath) as! DBItemTableViewCell
let element = elements[indexPath.row]
if let item = element as? DBItem {
cell.configureCellWithItem(item)
} else if let set = element as? DBSet {
cell.configureCellWithSet(set)
}
// HERE
cell.delegate = self
return cell
}
单元格的委托属性定义如下：
var delegate: DBItemTableViewCellDelegate?
这会在单元格和委托（视图控制器）之间创建强引用。表格视图也保留了单元格。这会创建一个保留周期。
您需要将委托属性的定义更改为weak：
weak var delegate: DBItemTableViewCellDelegate?
根据comment 进行修改：
您的DBItemTableViewCellDelegate定义需要定义为class-only protocol
protocol DBItemTableViewCellDelegate: class {
...
}