我有一个stack view
如下图所示:
所以我改变了高度image
以编程方式使其适合从我的服务器下载的图像,如果没有图像,则高度限制image
将设置为零。
这是我这样做的代码:
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)
}
上面的代码中,图像高度是根据从网上下载的实际图像高度进行缩放的。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”高度变高以适应实际图像高度时,我都会遇到以下错误
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)>"
)
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。我什至禁用了所有可以更改“图像”高度的代码,一旦禁用,就没有问题了。只有当我打算更改时才会出现错误高度。
我什至尝试添加ImageView.translatesAutoresizingMaskIntoConstraints = false
before layoutIfNeeded()
,但错误仍然存在。
那么改变图像高度以适应从服务器下载的实际图像的正确方法是什么?