Swift NSScrollView 更好的 NSViewBoundsDidChangeNotification 观察? [英] Swift NSScrollView better NSViewBoundsDidChangeNotification observing?

问题描述

有没有更好的方法来观察 NSScrollView -> NSClipView 框架/边界变化?这是翻译成 Swift 的 Obj-C 代码:

Is there a better way to observe NSScrollView -> NSClipView frame/bounds change? This is Obj-C code translated to Swift:

public override init(frame frameRect: NSRect) {
    self.contentView.postsFrameChangedNotifications = true;
    NSNotificationCenter.defaultCenter().addObserver(
        self,
        selector: "frameDidChange:",
        name: NSViewFrameDidChangeNotification,
        object: self.contentView)
}

deinit {
    NSNotificationCenter.defaultCenter().removeObserver(
        self,
        name: NSViewFrameDidChangeNotification,
        object: self.contentView)
}

它有效，但我不想使用 NSNotificationCenter.我想在 NSClipView 上使用框架属性观察:

It works, but I don't want to use NSNotificationCenter. I want to use frame property observation on NSClipView:

class MyClipView: NSClipView {
    ...

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        self.postsFrameChangedNotifications = true;
    }

   override var frame: CGRect {
        didSet {
            println("Did set frame")
        }
    }
}

但是 didSet 在初始化后只被调用了 2 次，并且在滚动封闭 NSScrollView 时它永远不会被调用.看起来苹果是使用内部方法来改变框架而不调用框架属性?

But didSet is called only 2 times after initialisation and it's never called when enclosing NSScrollView is scrolled. Looks that Apple is using internal methods to change the frame without calling frame property?

同样代表 NSViewBoundsDidChangeNotification 和 bounds 属性.

The same stands for NSViewBoundsDidChangeNotification and bounds property.

推荐答案

并非所有对 frame 变量的更改都必须通过属性发生:
==> 因此 didSet 没有捕获"所有

not every change to the frame variable has to happen through the property:
==> therefore the didSet doesn't 'catch' all

方法旁边的setFrame(框架的setter)
还有其他方法:setFrameOrigin 和 setFrameSize 甚至 setFrameRotation

next to the method setFrame (the setter for the frame)
there are also other ways: setFrameOrigin and setFrameSize and even setFrameRotation

边界相同

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