UIAlertController 与 UICollectionViewFlowLayout 冲突
UIAlertController conflicts with UICollectionViewFlowLayout
大家好，新年快乐！
我有一个奇怪的问题，我的 UICollectionViewFlowLayout 扩展与 UIAlertController 冲突，并删除了它的按钮。
我的应用有一个启用了分页的 uicollectionviewcontroller，我的 uicollectionviewflowlayout 扩展确保单个单元格填满整个屏幕
// Extension to make a UICollectionViewCell fill the whole screen
extension UICollectionViewFlowLayout {
public override func prepareLayout() {
let ratio : CGFloat = 5.6 / 8.7
let cardHeight = collectionView!.frame.height * 0.7
let cardWidth = cardHeight * ratio
let spacing = (collectionView!.frame.height - cardHeight) / 2
itemSize = CGSize(width: cardWidth, height: cardHeight)
minimumLineSpacing = spacing*2
sectionInset = UIEdgeInsets(top: spacing, left: 0, bottom: spacing, right: 0)
}
}
每当我调用 UIAlertController
let alertController = UIAlertController(title: "Error", message: "Error", preferredStyle: .Alert)
alertController.addAction(UIAlertAction(title: "OK", style: .Cancel) { (action) in })
self.presentViewController(alertController, animated: true) {}
我在控制台中收到以下消息
2016-01-01 21:04:48.924 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c4e80 h=--& v=--& H:[_UIAlertControllerActionView:0x15f53d9e0(19.8253)]>",
"<NSLayoutConstraint:0x15f67b370 H:|-(>=12)-[UIView:0x15f53e0c0] (Names: '|':_UIAlertControllerActionView:0x15f53d9e0 )>",
"<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>
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.
2016-01-01 21:04:48.926 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c62a0 h=--& v=--& V:[_UIAlertControllerActionView:0x15f53d9e0(30.8)]>",
"<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>
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.
2016-01-01 21:04:48.927 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c4e80 h=--& v=--& H:[_UIAlertControllerActionView:0x15f53d9e0(19.8253)]>",
"<NSLayoutConstraint:0x15f67b370 H:|-(>=12)-[UIView:0x15f53e0c0] (Names: '|':_UIAlertControllerActionView:0x15f53d9e0 )>",
"<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>
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.
2016-01-01 21:04:48.927 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c62a0 h=--& v=--& V:[_UIAlertControllerActionView:0x15f53d9e0(30.8)]>",
"<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>
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.
2016-01-01 21:04:48.938 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c4e80 h=--& v=--& H:[_UIAlertControllerActionView:0x15f53d9e0(19.8253)]>",
"<NSLayoutConstraint:0x15f67b370 H:|-(>=12)-[UIView:0x15f53e0c0] (Names: '|':_UIAlertControllerActionView:0x15f53d9e0 )>",
"<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>
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.
2016-01-01 21:04:48.940 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c62a0 h=--& v=--& V:[_UIAlertControllerActionView:0x15f53d9e0(30.8)]>",
"<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>
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.
虽然我的 UIAlertControllers 上的按钮没有出现，请看图片
有什么建议吗？
基于 Mattvens 答案的解决方案
我没有做扩展，而是做了一个子类：
class FullCellLayout: UICollectionViewFlowLayout {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
let ratio : CGFloat = 5.6 / 8.7
let cardHeight = UIScreen.mainScreen().bounds.height * 0.7
let cardWidth = cardHeight * ratio
let spacing = (UIScreen.mainScreen().bounds.height - cardHeight) / 2
itemSize = CGSize(width: cardWidth, height: cardHeight)
minimumLineSpacing = spacing*2
sectionInset = UIEdgeInsets(top: spacing, left: 0, bottom: spacing, right: 0)
}
}
简答：不要为此使用扩展程序。
Swift 中的扩展是全局的，因此您对 UICollectionViewLayout 的扩展影响 all UICollectionViewLayout 类.
根据您收到的错误判断，UIAlertController 在内部使用 UICollectionView 布局按钮，而您的扩展程序破坏了该功能。
你应该使用一个子类，如果你真的需要它，但没有理由（据我所知）你不能初始化 UICollectionViewFlowLayout，将它分配给 var 并使用它.
大家好，新年快乐！
我有一个奇怪的问题，我的 UICollectionViewFlowLayout 扩展与 UIAlertController 冲突，并删除了它的按钮。
我的应用有一个启用了分页的 uicollectionviewcontroller，我的 uicollectionviewflowlayout 扩展确保单个单元格填满整个屏幕
// Extension to make a UICollectionViewCell fill the whole screen
extension UICollectionViewFlowLayout {
public override func prepareLayout() {
let ratio : CGFloat = 5.6 / 8.7
let cardHeight = collectionView!.frame.height * 0.7
let cardWidth = cardHeight * ratio
let spacing = (collectionView!.frame.height - cardHeight) / 2
itemSize = CGSize(width: cardWidth, height: cardHeight)
minimumLineSpacing = spacing*2
sectionInset = UIEdgeInsets(top: spacing, left: 0, bottom: spacing, right: 0)
}
}
每当我调用 UIAlertController
let alertController = UIAlertController(title: "Error", message: "Error", preferredStyle: .Alert)
alertController.addAction(UIAlertAction(title: "OK", style: .Cancel) { (action) in })
self.presentViewController(alertController, animated: true) {}
我在控制台中收到以下消息
2016-01-01 21:04:48.924 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c4e80 h=--& v=--& H:[_UIAlertControllerActionView:0x15f53d9e0(19.8253)]>",
"<NSLayoutConstraint:0x15f67b370 H:|-(>=12)-[UIView:0x15f53e0c0] (Names: '|':_UIAlertControllerActionView:0x15f53d9e0 )>",
"<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>
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.
2016-01-01 21:04:48.926 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c62a0 h=--& v=--& V:[_UIAlertControllerActionView:0x15f53d9e0(30.8)]>",
"<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>
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.
2016-01-01 21:04:48.927 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c4e80 h=--& v=--& H:[_UIAlertControllerActionView:0x15f53d9e0(19.8253)]>",
"<NSLayoutConstraint:0x15f67b370 H:|-(>=12)-[UIView:0x15f53e0c0] (Names: '|':_UIAlertControllerActionView:0x15f53d9e0 )>",
"<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>
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.
2016-01-01 21:04:48.927 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c62a0 h=--& v=--& V:[_UIAlertControllerActionView:0x15f53d9e0(30.8)]>",
"<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>
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.
2016-01-01 21:04:48.938 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c4e80 h=--& v=--& H:[_UIAlertControllerActionView:0x15f53d9e0(19.8253)]>",
"<NSLayoutConstraint:0x15f67b370 H:|-(>=12)-[UIView:0x15f53e0c0] (Names: '|':_UIAlertControllerActionView:0x15f53d9e0 )>",
"<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67b3c0 UIView:0x15f53e0c0.trailing <= _UIAlertControllerActionView:0x15f53d9e0.trailing - 12>
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.
2016-01-01 21:04:48.940 Jeg Har Aldrig[10912:3649777] 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)
(
"<NSAutoresizingMaskLayoutConstraint:0x15f6c62a0 h=--& v=--& V:[_UIAlertControllerActionView:0x15f53d9e0(30.8)]>",
"<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x15f67bd50 V:[_UIAlertControllerActionView:0x15f53d9e0(>=44)]>
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.
虽然我的 UIAlertControllers 上的按钮没有出现，请看图片
有什么建议吗？
基于 Mattvens 答案的解决方案
我没有做扩展，而是做了一个子类：
class FullCellLayout: UICollectionViewFlowLayout {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
let ratio : CGFloat = 5.6 / 8.7
let cardHeight = UIScreen.mainScreen().bounds.height * 0.7
let cardWidth = cardHeight * ratio
let spacing = (UIScreen.mainScreen().bounds.height - cardHeight) / 2
itemSize = CGSize(width: cardWidth, height: cardHeight)
minimumLineSpacing = spacing*2
sectionInset = UIEdgeInsets(top: spacing, left: 0, bottom: spacing, right: 0)
}
}
简答：不要为此使用扩展程序。
Swift 中的扩展是全局的，因此您对 UICollectionViewLayout 的扩展影响 all UICollectionViewLayout 类.
根据您收到的错误判断，UIAlertController 在内部使用 UICollectionView 布局按钮，而您的扩展程序破坏了该功能。
你应该使用一个子类，如果你真的需要它，但没有理由（据我所知）你不能初始化 UICollectionViewFlowLayout，将它分配给 var 并使用它.