Ios UIView removeFromSuperview正在调用didMoveToSuperview

我不明白为什么UIView的

removeFromSuperview

正在调用

didMoveToSuperview

我认为只有在将视图添加到视图中时才会调用

didmovetoserview

。有人能解释一下为什么

removeFromSuperview

调用

didmovetoserview

以下是我在

removeFromSuperview

中所做的操作：

public override func removeFromSuperview() {

    clearDelegates()

    chaosPad?.removeFromSuperview()
    brushSliders?.removeFromSuperview()
    moodSlider?.removeFromSuperview()
    brushShapeMenu?.removeFromSuperview()
    moodMenu?.removeFromSuperview()
    gravityMenu?.removeFromSuperview()
    rotationMenu?.removeFromSuperview()

    menuGroups = []
    centerButtons = []
    scrollMenuItems = []
    menu?.removeFromSuperview()
    menu = nil

    super.removeFromSuperview()
}

func clearDelegates() {
    chaosPad?.delegate = nil
    viewController = nil
}

下面是调用堆栈，显示如何调用

didMoveToSuperview

：

#0  0x0000000110f39708 in specialized _fatalErrorMessage(StaticString, StaticString, StaticString, UInt) -> () ()
#1  0x000000010b9cb960 in TDTOilistMenuPainting.configureFrames() -> () at /FastDev/TDTPhotoLib/Oilist/Classes/TDTOilistMenuPainting.swift:161
#2  0x000000010b9cb83e in TDTOilistMenuPainting.didMoveToSuperview() -> () at /FastDev/TDTPhotoLib/Oilist/Classes/TDTOilistMenuPainting.swift:146
#3  0x000000010b9cb872 in @objc TDTOilistMenuPainting.didMoveToSuperview() -> () ()
#4  0x000000010f5d1db5 in __45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke ()
#5  0x000000010dc87c60 in -[NSISEngine withBehaviors:performModifications:] ()
#6  0x000000010f5d19b1 in -[UIView(Hierarchy) _postMovedFromSuperview:] ()
#7  0x000000010f5cf610 in __UIViewWasRemovedFromSuperview ()
#8  0x000000010f5cf107 in -[UIView(Hierarchy) removeFromSuperview] ()
#9  0x000000010b9c9aba in TDTOilistMenuPainting.removeFromSuperview() -> () at /FastDev/TDTPhotoLib/Oilist/Classes/TDTOilistMenuPainting.swift:73
#10 0x000000010ba6d269 in TDTPaintingViewController.(navigationController(UINavigationController, animationControllerForOperation : UINavigationControllerOperation, fromViewController : UIViewController, toViewController : UIViewController) -> UIViewControllerAnimatedTransitioning?).(closure #2) at /FastDev/TDTPhotoLib/Oilist/Classes/TDTPaintingViewController.swift:2706

---

这是正常的行为<每当视图的superview更改时，都会调用code>didMoveToSuperview，即使它更改为

nil

。您可以检查superview是否为nil或不在该方法中，以确定它是添加到superview还是从其superview中删除的，如：

override func didMoveToSuperview() {
    if let superview = self.superview {
        // the view was added as a subview to superview
    }
    else {
        // the view was removed from its superview
    }
}

---

你的意思是说“我认为只有当视图添加到视图中时才会调用

didMoveToSuperview

”？是的，谢谢你，我编辑了这篇文章。谢谢你的确认。我很惊讶它被调用。是的，它确实是一个命名奇怪的方法。我觉得苹果应该把它命名为superviewDidChange或者类似的东西。我完全同意@TylerTheCompiler令人惊讶的是，甚至已经这样描述了它：“告诉视图它的超级视图发生了变化。”