如何解决：无法同时满足约束条件
How to resolve : Unable to simultaneously satisfy constraints
我想这样创作（通过故事板完成）
这是通过故事板完成的。根据我的观察，我发现约束问题来自 "totalAmountImg"。我不更改所有对象的优先级 属性（所有对象的优先级 == 1000）
这是结果。 （SummaryVC - 以编程方式完成）
注意：我想让 SummaryVC totalAmountImg（以编程方式）看起来像上图（由故事板制作）
totalAmountImg 的 Storyboard 限制条件
这正是我通过代码创建的。但是我不知道为什么会弹出这个错误。
totalImgConstraint
func totalAmountImgConstraints() {
let imgCenterY = NSLayoutConstraint(item: totalAmountImg,
attribute: .centerY,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .centerY,
multiplier: 1.0,
constant: 0)
imgCenterY.identifier = "imgCenterY"
imgCenterY.isActive = true
let imgRight = NSLayoutConstraint(item: totalAmountImg,
attribute: .right,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .right,
multiplier: 1.0,
constant: 16)
imgRight.identifier = "imgRight"
imgRight.isActive = true
let imgAspectRatio = NSLayoutConstraint(item: totalAmountImg,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountImg,
attribute: .width,
multiplier: 1.0 / 1.0,
constant: 0)
imgAspectRatio.identifier = "imgAspectRatio"
imgAspectRatio.isActive = true
let imgLeft = NSLayoutConstraint(item: totalAmountImg,
attribute: .left,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .right,
multiplier: 1.0,
constant: 4)
imgLeft.identifier = "imgLeft"
imgLeft.isActive = true
let imgWidth = NSLayoutConstraint(item: totalAmountImg,
attribute: .width,
relatedBy: .lessThanOrEqual,
toItem: totalAmountView,
attribute: .width,
multiplier: 0.2,
constant: 0)
imgWidth.identifier = "imgWidth"
imgWidth.isActive = true
}
总结VC
class SummaryVC: UIViewController, UIScrollViewDelegate {
@IBOutlet weak var scrollView: UIScrollView!
@IBOutlet weak var pageController: UIPageControl!
let numberOfPages = 3
override func viewDidLoad() {
super.viewDidLoad()
basicDesignSetup()
// Add subViews
scrollView.addSubview(summaryBaseView)
scrollView.addSubview(paymentTypeBaseView)
scrollView.addSubview(itemNameBaseView)
summaryBaseView.addSubview(totalAmountView)
summaryBaseView.addSubview(runningTableView)
summaryBaseView.addSubview(partnerAmountView)
totalAmountView.addSubview(totalLbl)
totalAmountView.addSubview(totalPriceLbl)
totalAmountView.addSubview(totalAmountImg)
view.setNeedsUpdateConstraints()
// set content size
scrollView.contentSize = CGSize(width: scrollView.frame.width * CGFloat(numberOfPages), height: scrollView.frame.height)
}
override func viewDidLayoutSubviews() {
}
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
let pageNumber = scrollView.contentOffset.x / scrollView.frame.width
pageController.currentPage = Int(pageNumber)
pageController.currentPageIndicatorTintColor = UIColor.white
}
//-----------------------------------------------------------------
// MARK: - Methods
//-----------------------------------------------------------------
func basicDesignSetup() {
pageController.numberOfPages = numberOfPages
let scrollViewSize = scrollView.frame.size
let scrollViewWidth = scrollView.frame.width
// Summary View
let summeryOrigin = CGPoint(x: 0, y: 0)
summaryBaseView = UIView(frame: CGRect(origin: summeryOrigin, size: scrollViewSize))
summaryBaseView.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
// Payment Type View
let paymentTypeOrigin = CGPoint(x: scrollViewWidth, y: 0)
paymentTypeBaseView = UIView(frame: CGRect(origin: paymentTypeOrigin, size: scrollViewSize))
paymentTypeBaseView.backgroundColor = #colorLiteral(red: 0.01680417731, green: 0.1983509958, blue: 1, alpha: 1)
// Item Name View
let itemNameOrigin = CGPoint(x: scrollViewWidth * 2, y: 0)
itemNameBaseView = UIView(frame: CGRect(origin: itemNameOrigin, size: scrollViewSize))
itemNameBaseView.backgroundColor = #colorLiteral(red: 0, green: 0.9914394021, blue: 1, alpha: 1)
// Total Amount View
totalAmountView.backgroundColor = #colorLiteral(red: 0.5480614305, green: 0.8129847646, blue: 0.6160266995, alpha: 1)
runningTableView.backgroundColor = #colorLiteral(red: 0.4280827343, green: 0.7700845003, blue: 0.9571052194, alpha: 1)
partnerAmountView.backgroundColor = #colorLiteral(red: 0.9137254902, green: 0.4470588235, blue: 0.4549019608, alpha: 1)
totalLbl.text = "Total Amount"
totalLbl.textColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
totalLbl.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
totalLbl.font = UIFont.systemFont(ofSize: 16, weight: .medium)
totalPriceLbl.text = "5532.00"
totalPriceLbl.textColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
totalPriceLbl.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
totalAmountImg.contentMode = .scaleAspectFit
totalAmountImg.image = #imageLiteral(resourceName: "tick")
totalAmountImg.backgroundColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
}
//-----------------------------------------------------------------
// MARK: - Views - programatically
//-----------------------------------------------------------------
// Base Views
lazy var summaryBaseView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var paymentTypeBaseView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var itemNameBaseView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
// $$$$$ Summary Sub Views $$$$$
// Total Amount
lazy var totalAmountView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var totalLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var totalPriceLbl: UnderlinedLabel = {
let label = UnderlinedLabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var totalAmountImg: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
// Running Table
lazy var runningTableView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var runningLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var runningPriceLbl: UnderlinedLabel = {
let label = UnderlinedLabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var runningTableImg: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
// Partner Amount
lazy var partnerAmountView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var partnerLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var partnerPriceLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var partnerAmountImg: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
//-----------------------------------------------------------------
// MARK: - Constraints
//-----------------------------------------------------------------
override func updateViewConstraints() {
totalAmountViewConstraints()
runningTableViewConstraints()
partnerAmountViewConstraints()
// Total Amount View
totalLblConstraint()
totalPriceLblConstraints()
totalAmountImgConstraints()
super.updateViewConstraints()
}
func totalAmountViewConstraints() {
NSLayoutConstraint(item: totalAmountView,
attribute: .left,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .left,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .right,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .right,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .top,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .bottom,
relatedBy: .equal,
toItem: runningTableView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .height,
relatedBy: .equal,
toItem: runningTableView,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
}
func runningTableViewConstraints() {
NSLayoutConstraint(item: runningTableView,
attribute: .leading,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .leading,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .trailing,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .trailing,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .top,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .bottom,
relatedBy: .equal,
toItem: partnerAmountView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
}
func partnerAmountViewConstraints() {
NSLayoutConstraint(item: partnerAmountView,
attribute: .leading,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .leading,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .trailing,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .trailing,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .top,
relatedBy: .equal,
toItem: runningTableView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .bottom,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
}
// Total Ammount Section Subviews
func totalLblConstraint() {
NSLayoutConstraint(item: totalLbl,
attribute: .top,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .left,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .left,
multiplier: 1.0,
constant: 16).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .bottom,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .height,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .width,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .width,
multiplier: 0.7,
constant: 0).isActive = true
}
func totalPriceLblConstraints() {
NSLayoutConstraint(item: totalPriceLbl,
attribute: .top,
relatedBy: .equal,
toItem: totalLbl,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .leading,
relatedBy: .equal,
toItem: totalLbl,
attribute: .leading,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .bottom,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .height,
relatedBy: .equal,
toItem: totalLbl,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .width,
relatedBy: .equal,
toItem: totalLbl,
attribute: .width,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .trailing,
relatedBy: .equal,
toItem: totalLbl,
attribute: .trailing,
multiplier: 1.0,
constant: 0).isActive = true
}
func totalAmountImgConstraints() {
let imgCenterY = NSLayoutConstraint(item: totalAmountImg,
attribute: .centerY,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .centerY,
multiplier: 1.0,
constant: 0)
imgCenterY.identifier = "imgCenterY"
imgCenterY.isActive = true
let imgRight = NSLayoutConstraint(item: totalAmountImg,
attribute: .right,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .right,
multiplier: 1.0,
constant: 16)
imgRight.identifier = "imgRight"
imgRight.isActive = true
let imgAspectRatio = NSLayoutConstraint(item: totalAmountImg,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountImg,
attribute: .width,
multiplier: 1.0 / 1.0,
constant: 0)
imgAspectRatio.identifier = "imgAspectRatio"
imgAspectRatio.isActive = true
let imgLeft = NSLayoutConstraint(item: totalAmountImg,
attribute: .left,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .right,
multiplier: 1.0,
constant: 4)
imgLeft.identifier = "imgLeft"
imgLeft.isActive = true
let imgWidth = NSLayoutConstraint(item: totalAmountImg,
attribute: .width,
relatedBy: .lessThanOrEqual,
toItem: totalAmountView,
attribute: .width,
multiplier: 0.2,
constant: 0)
imgWidth.identifier = "imgWidth"
imgWidth.isActive = true
}
//-----------------------------------------------------------------
// MARK: - Actions
//-----------------------------------------------------------------
@IBAction func pageChange(_ sender: UIPageControl) {
let x = CGFloat(sender.currentPage) * scrollView.frame.width
scrollView.contentOffset = CGPoint(x: x, y: 0)
pageController.currentPageIndicatorTintColor = UIColor.white
}
}
extension NSLayoutConstraint {
override open var description: String {
let id = identifier ?? ""
return "id: \(id), constant: \(constant)" //you may print whatever you want here
}
}
日志
2018-01-12 16:27:27.934408+0530 Cafe Point[13577:258401] [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.
(Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"id: , constant: 343.0",
"id: , constant: 0.0",
"id: , constant: 0.0",
"id: , constant: 16.0",
"id: , constant: 0.0",
"id: , constant: 0.0",
"id: , constant: 0.0",
"id: imgLeft, constant: 4.0",
"id: imgRight, constant: 16.0",
"id: imgWidth, constant: 0.0"
)
Will attempt to recover by breaking constraint
id: imgLeft, constant: 4.0
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
如警告所述：
Will attempt to recover by breaking constraint id: imgLeft, constant:
4.0
您正在为图像视图提供左右约束。但也分配宽度。它混淆了图像视图，因为左右约束足以满足图像视图的宽度要求。
因此您可以使用两种组合：left/width 或 right/width。
您也可以使用其他组合，但为此，我们必须深入研究 Priority 的约束条件。
试试改成这样：
let imgRight = NSLayoutConstraint(item: totalAmountImg,
attribute: .right,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .right,
multiplier: 1.0,
constant: -16)
imgRight.identifier = "imgRight"
imgRight.isActive = true
（注意 16 变为 -16）
比较情节提要中的约束与以编程方式创建的约束时必须小心，因为顺序很重要。
要正确理解布局，请记住当您给视图 leading/left 和 trailing/right 约束时，您不必给它一个宽度，就好像您将长袍固定在两侧，如果你想给它一个宽度然后给它一个centerX约束，同样适用于顶部，底部然后不必给高度，如果你想给高度然后添加centerY约束，当然你可以给视图前导、尾随和宽度约束同时存在，但要确保它们合在一起
我想这样创作（通过故事板完成）
这是通过故事板完成的。根据我的观察，我发现约束问题来自 "totalAmountImg"。我不更改所有对象的优先级 属性（所有对象的优先级 == 1000）
这是结果。 （SummaryVC - 以编程方式完成）
注意：我想让 SummaryVC totalAmountImg（以编程方式）看起来像上图（由故事板制作）
totalAmountImg 的 Storyboard 限制条件
这正是我通过代码创建的。但是我不知道为什么会弹出这个错误。
totalImgConstraint
func totalAmountImgConstraints() {
let imgCenterY = NSLayoutConstraint(item: totalAmountImg,
attribute: .centerY,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .centerY,
multiplier: 1.0,
constant: 0)
imgCenterY.identifier = "imgCenterY"
imgCenterY.isActive = true
let imgRight = NSLayoutConstraint(item: totalAmountImg,
attribute: .right,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .right,
multiplier: 1.0,
constant: 16)
imgRight.identifier = "imgRight"
imgRight.isActive = true
let imgAspectRatio = NSLayoutConstraint(item: totalAmountImg,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountImg,
attribute: .width,
multiplier: 1.0 / 1.0,
constant: 0)
imgAspectRatio.identifier = "imgAspectRatio"
imgAspectRatio.isActive = true
let imgLeft = NSLayoutConstraint(item: totalAmountImg,
attribute: .left,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .right,
multiplier: 1.0,
constant: 4)
imgLeft.identifier = "imgLeft"
imgLeft.isActive = true
let imgWidth = NSLayoutConstraint(item: totalAmountImg,
attribute: .width,
relatedBy: .lessThanOrEqual,
toItem: totalAmountView,
attribute: .width,
multiplier: 0.2,
constant: 0)
imgWidth.identifier = "imgWidth"
imgWidth.isActive = true
}
总结VC
class SummaryVC: UIViewController, UIScrollViewDelegate {
@IBOutlet weak var scrollView: UIScrollView!
@IBOutlet weak var pageController: UIPageControl!
let numberOfPages = 3
override func viewDidLoad() {
super.viewDidLoad()
basicDesignSetup()
// Add subViews
scrollView.addSubview(summaryBaseView)
scrollView.addSubview(paymentTypeBaseView)
scrollView.addSubview(itemNameBaseView)
summaryBaseView.addSubview(totalAmountView)
summaryBaseView.addSubview(runningTableView)
summaryBaseView.addSubview(partnerAmountView)
totalAmountView.addSubview(totalLbl)
totalAmountView.addSubview(totalPriceLbl)
totalAmountView.addSubview(totalAmountImg)
view.setNeedsUpdateConstraints()
// set content size
scrollView.contentSize = CGSize(width: scrollView.frame.width * CGFloat(numberOfPages), height: scrollView.frame.height)
}
override func viewDidLayoutSubviews() {
}
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
let pageNumber = scrollView.contentOffset.x / scrollView.frame.width
pageController.currentPage = Int(pageNumber)
pageController.currentPageIndicatorTintColor = UIColor.white
}
//-----------------------------------------------------------------
// MARK: - Methods
//-----------------------------------------------------------------
func basicDesignSetup() {
pageController.numberOfPages = numberOfPages
let scrollViewSize = scrollView.frame.size
let scrollViewWidth = scrollView.frame.width
// Summary View
let summeryOrigin = CGPoint(x: 0, y: 0)
summaryBaseView = UIView(frame: CGRect(origin: summeryOrigin, size: scrollViewSize))
summaryBaseView.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
// Payment Type View
let paymentTypeOrigin = CGPoint(x: scrollViewWidth, y: 0)
paymentTypeBaseView = UIView(frame: CGRect(origin: paymentTypeOrigin, size: scrollViewSize))
paymentTypeBaseView.backgroundColor = #colorLiteral(red: 0.01680417731, green: 0.1983509958, blue: 1, alpha: 1)
// Item Name View
let itemNameOrigin = CGPoint(x: scrollViewWidth * 2, y: 0)
itemNameBaseView = UIView(frame: CGRect(origin: itemNameOrigin, size: scrollViewSize))
itemNameBaseView.backgroundColor = #colorLiteral(red: 0, green: 0.9914394021, blue: 1, alpha: 1)
// Total Amount View
totalAmountView.backgroundColor = #colorLiteral(red: 0.5480614305, green: 0.8129847646, blue: 0.6160266995, alpha: 1)
runningTableView.backgroundColor = #colorLiteral(red: 0.4280827343, green: 0.7700845003, blue: 0.9571052194, alpha: 1)
partnerAmountView.backgroundColor = #colorLiteral(red: 0.9137254902, green: 0.4470588235, blue: 0.4549019608, alpha: 1)
totalLbl.text = "Total Amount"
totalLbl.textColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
totalLbl.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
totalLbl.font = UIFont.systemFont(ofSize: 16, weight: .medium)
totalPriceLbl.text = "5532.00"
totalPriceLbl.textColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
totalPriceLbl.backgroundColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
totalAmountImg.contentMode = .scaleAspectFit
totalAmountImg.image = #imageLiteral(resourceName: "tick")
totalAmountImg.backgroundColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
}
//-----------------------------------------------------------------
// MARK: - Views - programatically
//-----------------------------------------------------------------
// Base Views
lazy var summaryBaseView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var paymentTypeBaseView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var itemNameBaseView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
// $$$$$ Summary Sub Views $$$$$
// Total Amount
lazy var totalAmountView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var totalLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var totalPriceLbl: UnderlinedLabel = {
let label = UnderlinedLabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var totalAmountImg: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
// Running Table
lazy var runningTableView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var runningLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var runningPriceLbl: UnderlinedLabel = {
let label = UnderlinedLabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var runningTableImg: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
// Partner Amount
lazy var partnerAmountView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var partnerLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var partnerPriceLbl: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
lazy var partnerAmountImg: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
//-----------------------------------------------------------------
// MARK: - Constraints
//-----------------------------------------------------------------
override func updateViewConstraints() {
totalAmountViewConstraints()
runningTableViewConstraints()
partnerAmountViewConstraints()
// Total Amount View
totalLblConstraint()
totalPriceLblConstraints()
totalAmountImgConstraints()
super.updateViewConstraints()
}
func totalAmountViewConstraints() {
NSLayoutConstraint(item: totalAmountView,
attribute: .left,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .left,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .right,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .right,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .top,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .bottom,
relatedBy: .equal,
toItem: runningTableView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalAmountView,
attribute: .height,
relatedBy: .equal,
toItem: runningTableView,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
}
func runningTableViewConstraints() {
NSLayoutConstraint(item: runningTableView,
attribute: .leading,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .leading,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .trailing,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .trailing,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .top,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .bottom,
relatedBy: .equal,
toItem: partnerAmountView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: runningTableView,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
}
func partnerAmountViewConstraints() {
NSLayoutConstraint(item: partnerAmountView,
attribute: .leading,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .leading,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .trailing,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .trailing,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .top,
relatedBy: .equal,
toItem: runningTableView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .bottom,
relatedBy: .equal,
toItem: summaryBaseView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: partnerAmountView,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
}
// Total Ammount Section Subviews
func totalLblConstraint() {
NSLayoutConstraint(item: totalLbl,
attribute: .top,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .left,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .left,
multiplier: 1.0,
constant: 16).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .bottom,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .top,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .height,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalLbl,
attribute: .width,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .width,
multiplier: 0.7,
constant: 0).isActive = true
}
func totalPriceLblConstraints() {
NSLayoutConstraint(item: totalPriceLbl,
attribute: .top,
relatedBy: .equal,
toItem: totalLbl,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .leading,
relatedBy: .equal,
toItem: totalLbl,
attribute: .leading,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .bottom,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .bottom,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .height,
relatedBy: .equal,
toItem: totalLbl,
attribute: .height,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .width,
relatedBy: .equal,
toItem: totalLbl,
attribute: .width,
multiplier: 1.0,
constant: 0).isActive = true
NSLayoutConstraint(item: totalPriceLbl,
attribute: .trailing,
relatedBy: .equal,
toItem: totalLbl,
attribute: .trailing,
multiplier: 1.0,
constant: 0).isActive = true
}
func totalAmountImgConstraints() {
let imgCenterY = NSLayoutConstraint(item: totalAmountImg,
attribute: .centerY,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .centerY,
multiplier: 1.0,
constant: 0)
imgCenterY.identifier = "imgCenterY"
imgCenterY.isActive = true
let imgRight = NSLayoutConstraint(item: totalAmountImg,
attribute: .right,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .right,
multiplier: 1.0,
constant: 16)
imgRight.identifier = "imgRight"
imgRight.isActive = true
let imgAspectRatio = NSLayoutConstraint(item: totalAmountImg,
attribute: .height,
relatedBy: .equal,
toItem: totalAmountImg,
attribute: .width,
multiplier: 1.0 / 1.0,
constant: 0)
imgAspectRatio.identifier = "imgAspectRatio"
imgAspectRatio.isActive = true
let imgLeft = NSLayoutConstraint(item: totalAmountImg,
attribute: .left,
relatedBy: .equal,
toItem: totalPriceLbl,
attribute: .right,
multiplier: 1.0,
constant: 4)
imgLeft.identifier = "imgLeft"
imgLeft.isActive = true
let imgWidth = NSLayoutConstraint(item: totalAmountImg,
attribute: .width,
relatedBy: .lessThanOrEqual,
toItem: totalAmountView,
attribute: .width,
multiplier: 0.2,
constant: 0)
imgWidth.identifier = "imgWidth"
imgWidth.isActive = true
}
//-----------------------------------------------------------------
// MARK: - Actions
//-----------------------------------------------------------------
@IBAction func pageChange(_ sender: UIPageControl) {
let x = CGFloat(sender.currentPage) * scrollView.frame.width
scrollView.contentOffset = CGPoint(x: x, y: 0)
pageController.currentPageIndicatorTintColor = UIColor.white
}
}
extension NSLayoutConstraint {
override open var description: String {
let id = identifier ?? ""
return "id: \(id), constant: \(constant)" //you may print whatever you want here
}
}
日志
2018-01-12 16:27:27.934408+0530 Cafe Point[13577:258401] [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.
(Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"id: , constant: 343.0",
"id: , constant: 0.0",
"id: , constant: 0.0",
"id: , constant: 16.0",
"id: , constant: 0.0",
"id: , constant: 0.0",
"id: , constant: 0.0",
"id: imgLeft, constant: 4.0",
"id: imgRight, constant: 16.0",
"id: imgWidth, constant: 0.0"
)
Will attempt to recover by breaking constraint
id: imgLeft, constant: 4.0
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
如警告所述：
Will attempt to recover by breaking constraint id: imgLeft, constant: 4.0
您正在为图像视图提供左右约束。但也分配宽度。它混淆了图像视图，因为左右约束足以满足图像视图的宽度要求。
因此您可以使用两种组合：left/width 或 right/width。
您也可以使用其他组合，但为此，我们必须深入研究 Priority 的约束条件。
试试改成这样：
let imgRight = NSLayoutConstraint(item: totalAmountImg,
attribute: .right,
relatedBy: .equal,
toItem: totalAmountView,
attribute: .right,
multiplier: 1.0,
constant: -16)
imgRight.identifier = "imgRight"
imgRight.isActive = true
（注意 16 变为 -16）
比较情节提要中的约束与以编程方式创建的约束时必须小心，因为顺序很重要。
要正确理解布局，请记住当您给视图 leading/left 和 trailing/right 约束时，您不必给它一个宽度，就好像您将长袍固定在两侧，如果你想给它一个宽度然后给它一个centerX约束，同样适用于顶部，底部然后不必给高度，如果你想给高度然后添加centerY约束，当然你可以给视图前导、尾随和宽度约束同时存在，但要确保它们合在一起