Ios 更新imageView swift 4的高度约束时无法同时满足约束

我有一个

堆栈视图

，如下图所示：

因此，我通过编程更改

图像的高度

以使其适合从我的服务器下载的图像，如果没有图像，则

图像

的高度限制将设置为零

以下是我执行此操作的代码：

    let imageUrl = URL(string :imageString)

    if let data = try? Data(contentsOf: imageUrl!)
    {

       guard let actualImage: UIImage = UIImage(data: data) else{
        print("No image!")
        ImageView.image = nil
       defaultImageHeightContrainst = ImageHeightContrainst.constant
       ImageHeightContrainst.constant = 0

        layoutIfNeeded()
        return
      }

     let imageHeight = actualImage.size.height * actualImage.scale
     print("imageHeight = \(imageHeight)")
     defaultImageHeightContrainst = ImageHeightContrainst.constant
     ImageHeightContrainst.constant = imageHeight

     layoutIfNeeded()

     //here display the image to the imageview
      ImageView.kf.setImage(with: imageUrl)

   }

根据上面的代码，图像高度根据从互联网下载的实际图像高度进行缩放。如果没有图像，“图像”部分也已设置为0

这是我所期望的，但现在每当“图像”高度变得更高以适合实际图像高度时，我都会遇到下面的错误

 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:0x6080002868b0 UIImageView:0x7f9cbae59240.height == 50   (active)>",
    "<NSLayoutConstraint:0x608000286bd0 UIView:0x7f9cbae5ad80.height == 1   (active)>",
    "<NSLayoutConstraint:0x608000286d10 UIImageView:0x7f9cbae5b440.height == 458   (active)>",
    "<NSLayoutConstraint:0x608000286f90 UIView:0x7f9cbae5bb50.height == 1   (active)>",
    "<NSLayoutConstraint:0x6080002871c0 V:|-(0)-[UILabel:0x7f9cbae5b160]   (active, names: '|':UIStackView:0x7f9cbae5af60 )>",
    "<NSLayoutConstraint:0x608000287350 V:[UILabel:0x7f9cbae5b160]-(10)-[UIImageView:0x7f9cbae5b440]   (active)>",
    "<NSLayoutConstraint:0x6080002873a0 V:[UIImageView:0x7f9cbae5b440]-(10)-[UIStackView:0x7f9cbae5b670]   (active)>",
    "<NSLayoutConstraint:0x608000287580 V:[UIStackView:0x7f9cbae5b670]-(10)-[UIView:0x7f9cbae5bb50]   (active)>",
    "<NSLayoutConstraint:0x6080002875d0 V:[UIStackView:0x7f9cbae5c0f0]-(0)-|   (active, names: '|':UIStackView:0x7f9cbae5af60 )>",
    "<NSLayoutConstraint:0x608000287670 V:[UIView:0x7f9cbae5bb50]-(10)-[UIStackView:0x7f9cbae5c0f0]   (active)>",
    "<NSLayoutConstraint:0x6080002877b0 V:|-(10)-[UIImageView:0x7f9cbae59240]   (active, names: '|':UITableViewCellContentView:0x7f9cbae5a0c0 )>",
    "<NSLayoutConstraint:0x6080002878f0 V:[UIImageView:0x7f9cbae59240]-(8)-[UIView:0x7f9cbae5ad80]   (active)>",
    "<NSLayoutConstraint:0x6080002879e0 V:[UIStackView:0x7f9cbae5af60]-(10)-|   (active, names: '|':UITableViewCellContentView:0x7f9cbae5a0c0 )>",
    "<NSLayoutConstraint:0x608000287a80 V:[UIView:0x7f9cbae5ad80]-(8)-[UIStackView:0x7f9cbae5af60]   (active)>",
    "<NSLayoutConstraint:0x608000288c00 'UISV-canvas-connection' UIStackView:0x7f9cbae5c0f0.top == _UILayoutSpacer:0x6080001cd5c0'UISV-alignment-spanner'.top   (active)>",
    "<NSLayoutConstraint:0x608000288ca0 'UISV-canvas-connection' V:[_UILayoutSpacer:0x6080001cd5c0'UISV-alignment-spanner']-(0)-|   (active, names: '|':UIStackView:0x7f9cbae5c0f0 )>",
    "<NSLayoutConstraint:0x608000289970 'UIView-Encapsulated-Layout-Height' UITableViewCellContentView:0x7f9cbae5a0c0.height == 476.5   (active)>"
)

下面列表中可能至少有一个约束是您不想要的约束。
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。
(
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
"",
""
)

在询问之前，我已经检查了所有其他约束，这些约束都设置正确。我甚至禁用了所有可以更改“图像”高度的代码，一旦禁用，就没有问题。错误只发生在我打算更改高度时

我甚至尝试在

layoutifneed（）

之前添加

ImageView.translatesAutoresizingMaskIntoConstraints=false

，但错误仍然存在

---

那么，为了适应从服务器下载的实际图像，更改图像高度的正确方法是什么呢

"<NSLayoutConstraint:0x608000289970 'UIView-Encapsulated-Layout-Height' UITableViewCellContentView:0x7f9cbae5a0c0.height == 476.5   (active)>"

如果在序列图像板中进行布局，只需在序列图像板中选择适当的约束，并在属性检查器中将其优先级设置为999（例如）：

---

您是否可以为共享完整的登录控制台constraints@Sh_Khanbro已经更新了您为UIStackView设置了什么分布类型？很可能，stackview是否位于使用

UITableViewAutomaticDimension

自动计算其高度的

UITableViewCell

中？

let bottomConstraint = tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
bottomConstraint.priority = UILayoutPriority(rawValue: 999)
NSLayoutConstraint.activate([
    // rest of the constraints
    stackView.topAnchor.constraint(equalTo: contentView.topAnchor),
    stackView.leftAnchor.constraint(equalTo: contentView.leftAnchor),
    stackView.rightAnchor.constraint(equalTo: contentView.rightAnchor),
    bottomConstraint,
])