如何定位一个NSView在另一个NSView下面?

Question

大家好，

谁知道如何定位NSButton在父视图下的另一个视图?

这是我写的代码，但是NSButton的位置不会改变，不管NSView在哪里。如果有人能调查一下并帮我解决这个问题，我将不胜感激。

@objc func printHello() {
var theButton = NSButton(frame: NSRect(x: 0, y: 0, width: 168, height: 32))
theButton.bezelStyle = .rounded
theButton.controlSize = .large
theButton.keyEquivalent = "r"
theButton.title = "Edit Chart Data"
self.superview?.addSubview(theButton, positioned: .below, relativeTo: self)
print(self.frame)

Answer 1

方法addSubview(theButton, positioned: .below, relativeTo: self)没有定义项目的帧位置。定位:.below;部分实际上表示Z坐标

你所做的就是告诉视图在"self"下面添加一个子视图在它的等级制度中。这意味着如果self和按钮的帧重叠，那么self将在按钮的前面。使用.above将把按钮放在前面。

您可以使用frame属性来实现您的目标或约束。如果是frame，则应该是

func placeView(_ targetView: NSView, belowView currentView: NSView) {
targetView.frame = NSRect(x: currentView.frame.minX,
y: currentView.frame.minY-currentView.frame.height,
width: currentView.frame.width,
height: currentView.frame.height)
}

使用方式:

self.superview?.addSubview({
let theButton = NSButton(frame: .zero)
placeView(theButton, belowView: self)
theButton.bezelStyle = .rounded
theButton.controlSize = .large
theButton.keyEquivalent = "r"
theButton.title = "New view"
return theButton
}())

当使用约束时，可以这样做:

func placeView(_ targetView: NSView, belowView currentView: NSView) {
let view = targetView.superview!
view.addConstraint(NSLayoutConstraint(item: currentView, attribute: .leading, relatedBy: .equal, toItem: targetView, attribute: .leading, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: currentView, attribute: .trailing, relatedBy: .equal, toItem: targetView, attribute: .trailing, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: currentView, attribute: .top, relatedBy: .equal, toItem: targetView, attribute: .bottom, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: currentView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: currentView.frame.height))
}

并像这样使用:

let theButton: NSButton = {
let theButton = NSButton(frame: NSRect(x: 0, y: 0, width: 0, height: 90.0))
theButton.translatesAutoresizingMaskIntoConstraints = false
theButton.bezelStyle = .rounded
theButton.controlSize = .large
theButton.keyEquivalent = "r"
theButton.title = "New view"
return theButton
}()
self.view.addSubview(theButton)
placeView(theButton, belowView: someView)
self.view.layoutSubtreeIfNeeded()