Ios 水平视图拉伸子视图

我有以下问题，无法理解为什么不遵守ImageView宽度约束，它会填充StackView上的剩余空间

import UIKit
import PlaygroundSupport

let view = UIView(frame: CGRect(x: 0, y: 0, width: 500, height: 800))

let imageView = UIView(frame: CGRect.zero)
imageView.backgroundColor = UIColor.red

imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.heightAnchor.constraint(equalToConstant: 40).isActive = true
imageView.widthAnchor.constraint(equalToConstant: 40).isActive = true

let navBarHeaderStackView = UIStackView()
navBarHeaderStackView.distribution = .equalCentering
navBarHeaderStackView.alignment = .center
navBarHeaderStackView.axis = .horizontal
navBarHeaderStackView.addArrangedSubview(imageView)
//navBarHeaderStackView.addArrangedSubview(titlesStackView)

view.addSubview(navBarHeaderStackView)
navBarHeaderStackView.translatesAutoresizingMaskIntoConstraints = false

navBarHeaderStackView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 50).isActive = true
navBarHeaderStackView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 8).isActive = true
navBarHeaderStackView.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
navBarHeaderStackView.heightAnchor.constraint(equalToConstant: 60).isActive = true

navBarHeaderStackView.backgroundColor = UIColor.blue

PlaygroundPage.current.liveView = view

---

因为这个限制

navBarHeaderStackView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 8).isActive = true

---

由于此限制，请对其进行注释并重试

navBarHeaderStackView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 8).isActive = true

---

对其进行注释，然后尝试将

牵引锚设置为
lessThanOrEqualTo
而不是
equalTo

navBarHeaderStackView.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor, constant: 8).isActive = true

将
trailingAnchor
设置为
lessThanOrEqualTo
而不是
equalTo

navBarHeaderStackView.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor, constant: 8).isActive = true