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UIAlertController中的内存泄漏关闭

uialertcontroller protocols memory-leaks swift

PaFi · 技术社区 · 7 年前

我在设置 UIAlertController ,我也看到过其他关于内存泄漏的帖子 UIAlertController .但我想不出如何更改代码以消除内存泄漏。我变了 itemSelected 从函数到计算属性,但它没有改变任何东西。

 protocol TriggerUIAlertController: class where Self: UIView {
        var itemsForPresenting: [String] { get }
        var titleForCancel: String { get }
        var titleForAlertController: String { get }
        var itemSelected: Int? {get set}
    }

    extension TriggerUIAlertController {

         func triggerUIAlerController() {
            let alertList = UIAlertController(title: titleForAlertController, message: nil, preferredStyle: .actionSheet)
            let closure = { (alert: UIAlertAction!) -> Void in
                let index = alertList.actions.index(of: alert)
                guard index != nil else {
                    return
                }

                ///produces memory leak, idk why though -> has to be checked
                self.itemSelected = index!
            }
            for x in itemsForPresenting {
                alertList.addAction(UIAlertAction(title: x, style: .default, handler: closure))
            }
            self.window?.rootViewController?.present(alertList,animated: true, completion: nil)
            let cancelAction = UIAlertAction(title: titleForCancel, style: .cancel, handler: nil)
            alertList.addAction(cancelAction)
        }
    }

顺便问一下:仪器在使用大约五分钟后总共使用50gb内存,这正常吗?

1 回复 | 直到 7 年前

Renaud 7 年前

它不是由UIAlertController引起的泄漏,而是更一般地由“保留周期”引起的,您可以在每个包含 self 或者在闭包之外创建的任何变量。

您可以通过更改闭包的“定义”来避免它:

  let closure = { [weak self, weak alertList] (alert: UIAlertAction!) -> Void in
        guard let self = self, let alertList = alertList, let index = alertList.actions.index(of: alert) else { return }               
            self.itemSelected = index

你可以在这里找到更完整的解释: Swift closures causing strong retain cycle with self

代码审查:关闭的另一个实现可以是:

  let closure = { [weak self, weak alertList] alert in
        guard let self = self, let alertList = alertList, let index = alertList.actions.index(of: alert) else { 
            return
        }               
        self.itemSelected = index
  }

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