如何以編程方式將筆尖添加到UIStackView

Question

我正在嘗試從筆尖添加任意數量的視圖到UIStackView中。 問題是，如果只包含一個視圖，則該視圖會增長為填充整個堆棧視圖，而不是保持適當的寬度。 到目前為止，這是我的代碼：

friendStackView.autoresizingMask = .flexibleWidth
friendStackView.translatesAutoresizingMaskIntoConstraints = false

let friendView = Bundle.main.loadNibNamed("FriendView", owner: self, options: nil)?.first as! FriendViewController
friendStackView.addArrangedSubview(friendView)
friendView.heightAnchor.constraint(equalToConstant: 150).isActive = true
friendView.widthAnchor.constraint(equalToConstant: 120).isActive = true

它導致以下調試：

[LayoutConstraints] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: 
        (1) look at each constraint and try to figure out which you don't expect; 
        (2) find the code that added the unwanted constraint or constraints and fix it. 
(
    "<NSLayoutConstraint:0x14eb9eb0 UIStackView:0x14ee6ed0.width == 500   (active)>",
    "<NSLayoutConstraint:0x14ef83f0 XXX.FriendViewController:0x14ef2090.width == 120   (active)>",
    "<NSLayoutConstraint:0x14def090 'UISV-canvas-connection' UIStackView:0x14ee6ed0.leading == XXX.FriendViewController:0x14ef2090.leading   (active)>",
    "<NSLayoutConstraint:0x14def230 'UISV-canvas-connection' H:[XXX.FriendViewController:0x14ef2090]-(0)-|   (active, names: '|':UIStackView:0x14ee6ed0 )>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x14ef83f0 XXX.FriendViewController:0x14ef2090.width == 120   (active)>

Answer 1

您在這里有一個沖突，stackView width = 500，並且您正在嘗試提供應該填充整個寬度120的子視圖

"<NSLayoutConstraint:0x14eb9eb0 UIStackView:0x14ee6ed0.width == 500   (active)>",
"<NSLayoutConstraint:0x14ef83f0 XXX.FriendViewController:0x14ef2090.width == 120