Swift 无法满足嵌套堆栈视图的约束

我试着调试控制台中的

无法满足约束

警告，这会在我从iPhone纵向过渡到iPhone横向时出现，我慢慢变得疯狂。我正在使用带有嵌套堆栈视图的仪表板类型视图。如果“宽度大小”类别为规则，则顶部堆栈将轴更改为.horizontal

视图层次结构：

• 看法
  • 滚动视图
    • 基本视图
      • 仪表板堆栈视图
        • 顶部堆栈视图
          • 进度视图
          • 统计视图
        • 中间视图
        • 底视图

代码

• 所有组件在

  viewDidLoad

• 当检测到大小类更改时，将操纵约束

调试器输出 当我将iPhone从纵向旋转到横向时会收到此信息

[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. 
(
    "id: , constant: 0.0",
    "id: , constant: 0.0",
    "id: , constant: 0.0",
    "id: , constant: 0.0",
    "id: progressWidth, constant: 224.0",
    "id: s, constant: 5.0",
    "id: scrollTrail, constant: 5.0",
    "id: UIScrollView-frameLayoutGuide-width, constant: 0.0",
    "id: UISV-canvas-connection, constant: 0.0",
    "id: UISV-canvas-connection, constant: 0.0",
    "id: UISV-canvas-connection, constant: 0.0",
    "id: UIView-Encapsulated-Layout-Width, constant: 896.0",
    "id: UIViewSafeAreaLayoutGuide-left, constant: 44.0",
    "id: UIViewSafeAreaLayoutGuide-right, constant: 44.0"
)

Will attempt to recover by breaking constraint 
id: progressWidth, constant: 224.0

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.
2020-02-26 11:27:51.128311+0000 Haem Data PG Std[9632:2228108] [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. 
(
    "id: progressHeight, constant: 414.0",
    "id: topStackHeight, constant: 185.0",
    "id: UISV-canvas-connection, constant: 0.0",
    "id: UISV-canvas-connection, constant: 0.0"
)

Will attempt to recover by breaking constraint 
id: progressHeight, constant: 414.0

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.

[LayoutConstraints]无法同时满足约束。
可能下面列表中至少有一个约束是您不想要的。
试试这个：
（1） 看看每一个约束，试着找出你不期望的；
（2） 找到添加了不需要的约束的代码，然后修复它。
(
“id:，常数：0.0”，
“id:，常数：0.0”，
“id:，常数：0.0”，
“id:，常数：0.0”，
“id:progressWidth，常数：224.0”，
“id:s，常数：5.0”，
“id:scrollTrail，常量：5.0”，
“id:UIScrollView frameLayoutGuide宽度，常数：0.0”，
“id:UISV画布连接，常量：0.0”，
“id:UISV画布连接，常量：0.0”，
“id:UISV画布连接，常量：0.0”，
“id:UIView封装布局宽度，常数：896.0”，
“id:UIViewSafeArealLayoutGuide左，常数：44.0”，
id:UIViewSafeArealLayoutGuide右侧，常数：44.0
)
将尝试通过打破约束进行恢复
id:progressWidth，常数：224.0
在UIViewAlertForUnsatifiableConstraints处创建一个符号断点，以便在调试器中捕获该断点。
中列出的UIView上UIConstraintBasedLayoutDebugging类别中的方法也可能会有所帮助。
2020-02-26 11:27:51.128311+0000 Haem数据PG Std[9632:2228108][布局约束]无法同时满足约束。
可能下面列表中至少有一个约束是您不想要的。
试试这个：
（1） 看看每一个约束，试着找出你不期望的；
（2） 找到添加了不需要的约束的代码，然后修复它。
(
“id:progressHeight，常数：414.0”，
“id:topStackHeight，常数：185.0”，
“id:UISV画布连接，常量：0.0”，
id:UISV画布连接，常数：0.0
)
将尝试通过打破约束进行恢复
id:progressHeight，常数：414.0
在UIViewAlertForUnsatifiableConstraints处创建一个符号断点，以便在调试器中捕获该断点。
中列出的UIView上UIConstraintBasedLayoutDebugging类别中的方法也可能会有所帮助。

依赖于其他布局操作的约束可能会变得棘手。“自动布局”在尝试满足所有约束时会生成多个“过程”

对于比例约束和可能受堆栈视图影响的约束（它们自己执行布局操作），这一点尤其明显

为了避免警告，通常需要调整约束优先级

而且，在激活/停用约束时，需要注意顺序

我按照您所示布置了对象，对于您的情况，您应该能够通过以下方式解决问题：

• 将

  progressViewHeight

  、

  progressViewWidth

  和

  topStackHeight

  约束的优先级分别更改为

  999

• 约束更改顺序应为
  • 应首先在视图/标签/etc上设置

    .isActive=false

  • 接下来应该更改视图/标签/etc上的

    .constant

    值
  • 然后在视图/标签等上设置

    .isActive=true

  • 然后更改堆栈视图上的

    .constant

    值
  • 最后更改堆栈视图的

    .axis

并非所有这些都是硬性规定，但从经验来看，这是一个好办法

尝试按上面列出的方式更改约束的优先级，并按如下方式更改

setupDashboardView（）

func：

func setupDashboardView() {
    let sizeClass = self.traitCollection

    if sizeClass.isIpad {
        progressViewHeight.isActive = false
        progressViewWidth.constant = (self.dashboardStack.bounds.width*0.25)
        topStackHeight.constant = (self.dashboardStack.bounds.height*0.3)
        topStack.axis = .horizontal
    } else if sizeClass.isIphonePortrait {
        progressViewWidth.isActive = false
        progressViewHeight.isActive = true
        progressViewHeight.constant = self.view.frame.width
        topStackHeight.constant = self.view.frame.width*1.5
        topStack.axis = .vertical
    } else if sizeClass.isIphoneLandscape {
        progressViewHeight.isActive = false
        progressViewWidth.constant = self.view.frame.width*0.25
        progressViewWidth.isActive = true
        topStackHeight.constant = self.view.frame.height*0.5
        topStack.axis = .horizontal
    }
    dashboardStack.spacing = 5
    topStack.spacing = 5

    // not needed
    //self.updateViewConstraints()

    // NEVER call this yourself
    //self.viewDidLayoutSubviews()
}

---

我相信我们需要查看

TopStackView

和

ProgressView

的约束，以便了解方向更改时实际激活的内容。

func setupDashboardView() {
    let sizeClass = self.traitCollection

    if sizeClass.isIpad {
        progressViewHeight.isActive = false
        progressViewWidth.constant = (self.dashboardStack.bounds.width*0.25)
        topStackHeight.constant = (self.dashboardStack.bounds.height*0.3)
        topStack.axis = .horizontal
    } else if sizeClass.isIphonePortrait {
        progressViewWidth.isActive = false
        progressViewHeight.isActive = true
        progressViewHeight.constant = self.view.frame.width
        topStackHeight.constant = self.view.frame.width*1.5
        topStack.axis = .vertical
    } else if sizeClass.isIphoneLandscape {
        progressViewHeight.isActive = false
        progressViewWidth.constant = self.view.frame.width*0.25
        progressViewWidth.isActive = true
        topStackHeight.constant = self.view.frame.height*0.5
        topStack.axis = .horizontal
    }
    dashboardStack.spacing = 5
    topStack.spacing = 5

    // not needed
    //self.updateViewConstraints()

    // NEVER call this yourself
    //self.viewDidLayoutSubviews()
}