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I am constructing a variable size table view within another view. The table view should not scroll so I am programmatically determining its content size and adjusting a height constraint so that the table view always fits its content.
The problem I run into is a warning about a broken constraint:
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:0x170498b00 h=--& v=--& UIView:0x1024f2c90.height == 322 (active)>",
"<NSLayoutConstraint:0x17428d660 UITableView:0x103152400.height == 322 (active)>",
"<NSLayoutConstraint:0x174482da0 V:[UITableView:0x103152400]-(27)-| (active, names: '|':UIView:0x1024f2c90 )>",
"<NSLayoutConstraint:0x17429da10 V:|-(16)-[UITableView:0x103152400] (active, names: '|':UIView:0x1024f2c90 )>"
)
To fix this, I tried 2 things:
Set translatesAutoresizingMaskIntoConstraints = false. This causes everything to go haywire with the table view.
Lower the priority of the adjustable height constraint to 999.
Point 2 solves my problem and I'm able to adjust the height of the view using the lower priority constraint. But, I don't understand why this works.
So, how does Auto Layout interpret the priority of a constraint? I would've expected the NSAutoresizingMaskLayoutConstraint to take over the lower priority constraint and make it so I could not resize the view using the constraint.
To answer the question in the headline: Lowering the priority of a constraint tells the autolayout that the constraint is less important than all constraints with a higher priority.
This means that if two constraints are conflicting autolayout will use the one with the highest priority and disregard the other.
If two required constraints with identical priorities conflict, you will have an error message like the one you describe.
Since you are setting the height at run time I would select the height/vertical constraint in IB you don't need at run time and turn the 'Placeholder' for the constraint to 'Remove at build time', this should remove your warnings.
The priority setting determines when there are conflicting constraints which one will be used.
I have a problem referring to an UIStackView. I created a StackView and added a few items bundled into another StackViews to it. Now I want to animate the inner StackViews with the hidden attribute to switch between different objects. For that I call StackView.hidden in code in ViewDidLoad for hiding the StackView with the items in it. The codes seems to work in Simulator, but it throws an error:
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.
(
"<NSLayoutConstraint:0x7fd29d00b460 'UISV-canvas-connection' UIStackView:0x7fd29acdb3b0.top == UIStackView:0x7fd29acdc120.top>",
"<NSLayoutConstraint:0x7fd29d00b5a0 'UISV-canvas-connection' V:[UISlider:0x7fd29accb620]-(0)-| (Names: '|':UIStackView:0x7fd29acdb3b0 )>",
"<NSLayoutConstraint:0x7fd29d00f8d0 'UISV-hiding' V:[UIStackView:0x7fd29acdb3b0(0)]>",
"<NSLayoutConstraint:0x7fd29d00b9a0 'UISV-spacing' V:[UIStackView:0x7fd29acdc120]-(10)-[UISlider:0x7fd29accb620]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7fd29d00b9a0 'UISV-spacing' V:[UIStackView:0x7fd29acdc120]-(10)-[UISlider:0x7fd29accb620]>
I identified the problem inside the inner StackView to be the Spacing. If I switch the spacing to 0, the problem disappears. But I don't want to miss the spacing. I think another option is to hide every single object inside the inner StackView, but that's an enormous effort and it's more simple to hide the StackView. Is there any idea how to fix that problem?
Thanks for your help!
Just for future reference: I have had this happen when I wanted to hide a UIStackView. I would suggest putting the UIStackView you wish to hide in another UIStackView with distribution set to fill not fill proportionally
I have six user constraints setup with IB that look like this:
H:|-(593)-[UIView(411)]-(20)-|
V:|-(20)-[UIView(288)]-(396)-|
I grow and shrink the view by changing the constraints and then calling layoutIfNeeded. For example, to grow the view I will do:
H:|-(20)-[UIView(984)]-(20)-|
V:|-(20)-[UIView(663)]-(20)-|
And then call
[UIView animateWithDuration:.5 animations:^{
[self.view layoutIfNeeded];
}];
This technique grows and shrinks my view, and it looks nice, but I'm given a rather confusing warning:
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)
(
"<NSLayoutConstraint:0x148d5af0 H:[UIView:0x148d4e50(411)]>",
"<NSLayoutConstraint:0x148cc940 H:[UITableView:0xace7600(319)]>",
"<NSLayoutConstraint:0x148ce040 H:|-(NSSpace(20))-[UITableView:0xacd4e00] (Names: '|':UIView:0x148cddd0 )>",
"<NSLayoutConstraint:0x148cdf00 H:[UITableView:0xace7600]-(NSSpace(20))-| (Names: '|':UIView:0x148cddd0 )>",
"<NSLayoutConstraint:0x148cdea0 H:[UITableView:0xacd4e00]-(NSSpace(8))-[UITableView:0xace7600]>",
"<NSLayoutConstraint:0x148d4c10 UIView:0x148cddd0.trailing == UIView:0x148cdd40.trailing>",
"<NSLayoutConstraint:0x148d4b90 H:|-(0)-[UIView:0x148cddd0] (Names: '|':UIView:0x148cdd40 )>",
"<NSLayoutConstraint:0x148d6020 H:|-(320)-[UIView:0x148cdd40] (Names: '|':UIView:0x148cd330 )>",
"<NSLayoutConstraint:0x148d5fa0 UIView:0x148cdd40.trailing == UIView:0x148cd330.trailing>",
"<NSLayoutConstraint:0x148d5f60 H:[UIView:0x148d4e50]-(NSSpace(20))-| (Names: '|':UIView:0x148cd330 )>",
"<NSLayoutConstraint:0x148d5ee0 H:|-(20)-[UIView:0x148d4e50] (Names: '|':UIView:0x148cd330 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x148cc940 H:[UITableView:0xace7600(319)]>
Now all of these constraints are generated by IB. I've double^(triple!) checked this. I've put these constraints together with a pen and paper and have gotten this:
UIView_A H:[-(20)-[UIView_E]-(20)-] and H:[-(320)-(UIView_B)
UIView_B H:[-(0)-[UIView_D]
UIView_C H:[UIView_C(411)]
UIView_D H:[-(20)-[UITableView_F]-[UITableView_G(319)]-(20)-]
I don't understand how these constraints can't be satisfied. They look fine. I don't change them and they're generated by IB. Aren't constraints generated by IB automatically satisfiable?
Or, at a minimum, is there a way to stop warnings? It behaves perfectly and I don't need to see that it's breaking a constraint that doesn't seem to do anything anyway.
This constraint:
H:[UITableView:0xace7600(319)]>"
seems to be an impediment for the system resolution.
Can you remove it ?
So, it turns out, the order at which I change constraints matters.
To grow the view, I will
Increase the width: H:|-(593)-[UIView(984)]-(20)-|
Decrease the leading space: H:|-(20)-[UIView(984)]-(20)-|
This produces no warnings. However, if I do this in the opposite order, I'll get a warning:
Unable to simultaneously satisfy constraints.
Probably at least one of the constraints ...
...Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x1567f650 H:[UITableView:0x119e6200(319)]>
When shrinking the view, I copied the code that increased the width (with the same order) and just changed the values. That gave me the warning I posted in my original question. When I switched the order for shrinking, the warnings disappeared.
Why is this the case? I don't know. I'll update as I discover more.
I got same message, and I finally got it why it happens,
My solution is: Do not let any object FLIP OVER during at any moment of the animation.
In other words, contraints are should be OUTside of any object,
but sometimes constraints are inside during animation, not like our expection.
In another words, do not let top margin invade bottom margin due to constraint animation.
For example,
top constraint: topA = initially 100
[Box A]
bottom constraint: botA = initially 150
now, if you set like below and animate,
topA = 300
botA = 25
then error should occur,
why: thread invades the bottom margin BEFORE bottom margin go down.
So,
You'd rather change the ORDER,
botA = 25
topA = 300
Then error will disappear because bottom constraint would preserve the height of the mass and next top constraint would shrink the object's height not invading the bottom margin.
*Point:
Let the object have width and height greater than 0 CONTINUALLY even during animation,
not interrupted by constraints change.
I hope I helped you.
I have gone through and removed every single user constraint yet I am still getting the following error ONLY after I rotate the device. I have absolutely no clue why though. Does anyone have any ideas?
2013-01-14 21:30:31.363 myApp[35869:c07] 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:0x84543d0 h=--& v=--& V:[UIView:0xa330270(768)]>",
"<NSLayoutConstraint:0xa338350 V:[UIView:0xa331260]-(-1)-| (Names: '|':UIView:0xa330270 )>",
"<NSLayoutConstraint:0xa338390 V:|-(841)-[UIView:0xa331260] (Names: '|':UIView:0xa330270 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0xa338350 V:[UIView:0xa331260]-(-1)-| (Names: '|':UIView:0xa330270 )>
Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
Let's look at these one by one.
"<NSAutoresizingMaskLayoutConstraint:0x84543d0 h=--& v=--& V:[UIView:0xa330270(768)]>"
This is saying view 0xa330270 (A) must be 768 points high.
"<NSLayoutConstraint:0xa338350 V:[UIView:0xa331260]-(-1)-| (Names: '|':UIView:0xa330270 )>"
This is saying view 0xa331260 (B)'s bottom edge must be a gap of -1 from the bottom of A, which is it's superview.
"<NSLayoutConstraint:0xa338390 V:|-(841)-[UIView:0xa331260] (Names: '|':UIView:0xa330270 )>"
This is saying that B's top edge must be a gap of 841 points from the top of its superview, A.
These three things can't all be true - A can't be 768 points high, and contain a subview with a top edge 841 points inset from the top and -1 points inset from the bottom. Where have you defined each of these constraints?
You haven't said what layout you are trying to achieve, but it looks like you might have an autoresizing mask on the superview that is preventing it changing in height when you rotate the device. As far as I know the autoresizing constraints only appear if you have added views programmatically, since a storyboard or xib is either all-autolayout, or not. Unless you are doing something like adding an auto laid out view (loaded from a nib?) to another view from a non-autolayout nib?
Its worth knowing the basics, and understand what Apple/Xcode is trying to tell you through the logs
H = Horizontal constraint(for leading and Trailing)
V = Vertical constraint(top and bottom edge)
h = height
w = width
TopEdge -> V:|-(points)-[VIEW:memoryAddress]
BottomEdge -> V:[VIEW:memoryAddress]-(points)-|
Leading -> H:|-(points)-[VIEW:memoryAddress]
Trailing -> H:[VIEW:memoryAddress] -(points)-|
height -> h= --& v=--& V:[VIEW:memoryAddress((points)]
width -> VIEW:memoryAddress.width == points
between -> H:[VIEW 1]-(51)-[VIEW 2]
Once you understand this, reading your specific error is pretty easy
thanks to http://useYourLoaf.com for this complete solution:
http://useyourloaf.com/blog/using-identifiers-to-debug-autolayout.html
A quick tip I found buried in a WWDC 2015 session on Auto Layout that helps when debugging problems with constraints
If you have used Auto Layout you will be familiar with the log that Xcode spits out when you get something wrong. To create an example I modified my Stack View sample code and added a constraint to each of the images to give them a fixed width of 240 (not a good idea as we will see).
That works in regular width views such as the iPad but is too wide for a compact width view such as the iPhone in portrait. The console log at runtime is not fun to read. Skipping the boilerplate text you get a list of the problematic constraints:
"<NSLayoutConstraint:0x7fc1ab520360 H:[UIImageView:0x7fc1ab532650(240)]>",
"<NSLayoutConstraint:0x7fc1ab536ef0 H:[UIImageView:0x7fc1ab537380(240)]>",
"<NSLayoutConstraint:0x7fc1ab545cc0 UIView:0x7fc1ab53d870.trailingMargin == UIStackView:0x7fc1ab53dae0.trailing>",
"<NSLayoutConstraint:0x7fc1ab545d10 UIStackView:0x7fc1ab53dae0.leading == UIView:0x7fc1ab53d870.leadingMargin>",
"<NSLayoutConstraint:0x7fc1ab54e240 'UISV-alignment' UIStackView:0x7fc1ab53dc70.centerX == UIStackView:0x7fc1ab531a10.centerX>",
"<NSLayoutConstraint:0x7fc1ab5167c0 'UISV-canvas-connection' UIStackView:0x7fc1ab531a10.leading == UIImageView:0x7fc1ab532650.leading>",
"<NSLayoutConstraint:0x7fc1ab54ad80 'UISV-canvas-connection' H:[UIImageView:0x7fc1ab537380]-(0)-| (Names: '|':UIStackView:0x7fc1ab531a10 )>",
"<NSLayoutConstraint:0x7fc1ab5397d0 'UISV-canvas-connection' UIStackView:0x7fc1ab53dae0.leading == _UILayoutSpacer:0x7fc1ab54c3c0'UISV-alignment-spanner'.leading>",
"<NSLayoutConstraint:0x7fc1ab54a4a0 'UISV-canvas-connection' UIStackView:0x7fc1ab53dae0.centerX == UIStackView:0x7fc1ab53dc70.centerX>",
"<NSLayoutConstraint:0x7fc1ab54b110 'UISV-spacing' H:[UIImageView:0x7fc1ab532650]-(16)-[UIImageView:0x7fc1ab537380]>",
"<NSLayoutConstraint:0x7fc1ab548210 'UISV-spanning-boundary' _UILayoutSpacer:0x7fc1ab54c3c0'UISV-alignment-spanner'.leading <= UIStackView:0x7fc1ab531a10.leading>",
"<NSLayoutConstraint:0x7fc1ab551690 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7fc1ab53d870(375)]>"
The log then tells you which of the above constraints it has decided to break:
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7fc1ab536ef0 H:[UIImageView:0x7fc1ab537380(240)]>
The log output uses the auto layout visual format language but it is hard to pick out my constraints from those created by the system. This is especially the case with stack views which are by design intended to create most of the constraints for you. In this trivial example I know the fixed width constraints that I just added broke things but it is hard to see that from the log and the more complex the view the harder it gets.
Adding an Identifier to a Constraint
The log gets a lot easier to understand if you add an identifier to each constraint (NSLayoutConstraint has had an identifier property since iOS 7). In Interface Builder find the constraint and add the identifier in the Attributes inspector (I am using $ as a prefix/suffix to make them stand out in the log):
Update 18-August-2015: As pointed out in the comments the identifier can only be edited in Interface Builder starting with Xcode 7. It is not visible in Xcode 6.4.
If adding the constraint in code:
constraint.identifier = "$HeartImageFixedWidth$"
It is trickier if you are using the visual format language which uses arrays of constraints. For example, consider the Swift code fragment to create a fixed width constraint for the heart image view:
let heartWidth = NSLayoutConstraint.constraintsWithVisualFormat("[heart(240)]",
options:[], metrics:nil, views:viewsDictionary)
Since heartWidth is an array of type [NSLayoutConstraint] setting the identifier is a little more work:
for constraint in heartWidth {
constraint.identifier = "$HeartImageFixedWidth$"
}
heartImage.addConstraints(heartWidth)
With identifies set for my constraints it is now much easier to find them in the log file (see the first four lines):
"<NSLayoutConstraint:0x7f92a305aeb0 '$ContainerStackViewLeading$' UIStackView:0x7f92a3053220.leading == UIView:0x7f92a3052fb0.leadingMargin + 32>",
"<NSLayoutConstraint:0x7f92a305b340 '$ContainerStackViewTrailing$' UIView:0x7f92a3052fb0.trailingMargin == UIStackView:0x7f92a3053220.trailing + 32>",
"<NSLayoutConstraint:0x7f92a301cf20 '$HeartImageFixedWidth$' H:[UIImageView:0x7f92a3047ef0(240)]>",
"<NSLayoutConstraint:0x7f92a3009be0 '$StarImageFixedWidth$' H:[UIImageView:0x7f92a304d190(240)]>",
"<NSLayoutConstraint:0x7f92a3060cc0 'UISV-alignment' UIStackView:0x7f92a30533b0.centerX == UIStackView:0x7f92a30472b0.centerX>",
"<NSLayoutConstraint:0x7f92a301c590 'UISV-canvas-connection' UIStackView:0x7f92a30472b0.leading == UIImageView:0x7f92a3047ef0.leading>",
"<NSLayoutConstraint:0x7f92a305f680 'UISV-canvas-connection' H:[UIImageView:0x7f92a304d190]-(0)-| (Names: '|':UIStackView:0x7f92a30472b0 )>",
"<NSLayoutConstraint:0x7f92a3064190 'UISV-canvas-connection' UIStackView:0x7f92a3053220.leading == _UILayoutSpacer:0x7f92a30608a0'UISV-alignment-spanner'.leading>",
"<NSLayoutConstraint:0x7f92a30415d0 'UISV-canvas-connection' UIStackView:0x7f92a3053220.centerX == UIStackView:0x7f92a30533b0.centerX>",
"<NSLayoutConstraint:0x7f92a305fa10 'UISV-spacing' H:[UIImageView:0x7f92a3047ef0]-(16)-[UIImageView:0x7f92a304d190]>",
"<NSLayoutConstraint:0x7f92a30508c0 'UISV-spanning-boundary' _UILayoutSpacer:0x7f92a30608a0'UISV-alignment-spanner'.leading <= UIStackView:0x7f92a30472b0.leading>",
"<NSLayoutConstraint:0x7f92a3063240 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7f92a3052fb0(375)]>"
It also much clearer which of the constraints the system has chosen to break:
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7f92a3009be0 '$StarImageFixedWidth$' H:[UIImageView:0x7f92a304d190(240)]>
Adding identifiers to constraints is not without effort but it can pay off the next time you have to sort through the debug log of a complex layout.
Further Reading
WWDC 2015 Session 219 Mysteries of Auto Layout, Part 2
I guess this is not a common error, but I solved it somewhat in a layman way. I was getting cryptic messages like the one above. To make sense of it, I created dummy view classes and attached it to the views in my storyboard. For example, if I had a UIView, I created a class called AddressView and attached it to this view in story board. Its a bit time consuming, but it worked for me. After that instead of object-ids, I got class names which helped me zero in on the views that were causing the issue very easily. My error message now read,
2013-07-02 04:16:20.434 Myproject [2908:c07] 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)
(
"<NSLayoutConstraint:0x9edeae0 V:|-(0)-[AddressView:0x143ee020] (Names: '|':MainView:0x129eb6a0 )>",
"<NSAutoresizingMaskLayoutConstraint:0x11e998c0 h=--& v=--& V:[MainView:0x129eb6a0(704)]>",
"<NSLayoutConstraint:0x156720b0 V:[AddressView:0x143ee020]-(896)-| (Names: '|':MainView:0x129eb6a0 )>"
)
Here you can see, the names of my views MainView and Address view are causing the issue.
To resolve it, I just moved my subview (in this case Address view) and repositioned it back. I think the issue began as I was using a mix of new Automatic Layour in Xcode 4.5 and old skills or manually positioning the views.
Anyways, not sure if it was more luck than diligence, but nevertheless this could be a different way of debugging. Maybe this helps someone!
YourConstraintView.translatesAutoresizingMaskIntoConstraints = NO;
Did it for me.
I've fixed this problem be deleting all translatesAutoresizingMaskIntoConstraints properties from xib file (Open xib as a source code).
One note. You get this error in logs if you are testing using a personal hotspot connection, and the hotspot status bar is at the top. It throws off the constraints.
Hope this helps someone.. was driving me nuts.
For me this error was spitted when I gave tableView.estimatedRowHeight = UITableViewAutomaticDimension
This should have been tableView.estimatedRowHeight = "Some hardcoded value"
I had this problem and took me 2 days to figure out the source of the problem....
If you open a storyboard programmatically in you code just make sure you do it like this:
UIStoryboard *story = [UIStoryboard storyboardWithName:#"MovieMaker" bundle:nil];
UIViewController *vc = [story instantiateInitialViewController];
//this causes layout to break [self presentViewController:vc animated:YES completion:nil];
[self showViewController:vc sender:nil];
I was using the commented line (using presentViewController) and the orientation bug has happening throwing constraints conflicts that weren't my constraints... changing to showViewController all constraints conflicts were gone and orientation works...... (I don't really know why it works with show and not present... still thinking it's... ALIENS...)
This issue of the generated message "Unable to simultaneously satisfy contraints" in the debug console, is also experienced in XCode 9.4.
In my particular instance on the iPad simulator, the message would generate:
1) Only when placing the focus on a particular UITextField.
2) Even with all view contraints removed.
2) Even with all view contraints "Reset to Suggested Contraints".
However, when the software keyboard was toggled on to display, the message would not be generated.
Therefore, how much time should I spend on this issue, that in my instance is only generated when the software keyboard is toggled off.
this line solved my problem when logs like above in uitableviewCell
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension > CellHeight.rowHeight44 ? UITableView.automaticDimension : CellHeight.rowHeight44
}
Below is the error message I receive in the debug area. It runs fine and nothing is wrong except that I receive this error. Would this prevent apple accepting the app? How do I fix it?
2012-07-26 01:58:18.621 Rolo[33597:11303] 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:0x887d630 h=--& v=--& V:[UIButtonLabel:0x886ed80(19)]>",
"<NSAutoresizingMaskLayoutConstraint:0x887d5f0 h=--& v=--& UIButtonLabel:0x886ed80.midY == + 37.5>",
"<NSAutoresizingMaskLayoutConstraint:0x887b4b0 h=--& v=--& V:[UIButtonLabel:0x72bb9b0(19)]>",
"<NSAutoresizingMaskLayoutConstraint:0x887b470 h=--& v=--& UIButtonLabel:0x72bb9b0.midY == - 0.5>",
"<NSLayoutConstraint:0x72bf860 V:[UILabel:0x72bf7c0(17)]>",
"<NSLayoutConstraint:0x72c2430 UILabel:0x72bfad0.top == UILabel:0x72bf7c0.top>",
"<NSLayoutConstraint:0x72c2370 UILabel:0x72c0270.top == UILabel:0x72bfad0.top>",
"<NSLayoutConstraint:0x72c22b0 V:[UILabel:0x72bf7c0]-(NSSpace(8))-[UIButton:0x886efe0]>",
"<NSLayoutConstraint:0x72c15b0 V:[UILabel:0x72c0270]-(NSSpace(8))-[UIRoundedRectButton:0x72bbc10]>",
"<NSLayoutConstraint:0x72c1570 UIRoundedRectButton:0x72bbc10.baseline == UIRoundedRectButton:0x7571170.baseline>",
"<NSLayoutConstraint:0x72c21f0 UIRoundedRectButton:0x7571170.top == UIButton:0x886efe0.top>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x72bf860 V:[UILabel:0x72bf7c0(17)]>
Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
I would recommend to debug and find which constraint is "the one you don't want". Suppose you have following issue:
Always the problem is how to find following Constraints and Views.
There are two solutions how to do this:
DEBUG VIEW HIERARCHY (Do not recommend this way)
Since you know where to find unexpected constraints (PBOUserWorkDayHeaderView) there is a way to do this fairly well. Let's find UIView and NSLayoutConstraint in red rectangles. Since we know their id in memory it is quite easy.
Stop app using Debug View Hierarchy:
Find the proper UIView:
The next is to find NSLayoutConstraint we care about:
As you can see, the memory pointers are the same. So we know what is going on now. Additionally you can find NSLayoutConstraint in view hierarchy. Since it is selected in View, it selected in Navigator also.
If you need you may also print it on console using address pointer:
(lldb) po 0x17dce920
<UIView: 0x17dce920; frame = (10 30; 300 24.5); autoresize = RM+BM; layer = <CALayer: 0x17dce9b0>>
You can do the same for every constraint the debugger will point to you:-) Now you decide what to do with this.
PRINT IT BETTER (I really recommend this way, this is of Xcode 7)
set unique identifier for every constraint in your view:
create simple extension for NSLayoutConstraint:
SWIFT:
extension NSLayoutConstraint {
override public var description: String {
let id = identifier ?? ""
return "id: \(id), constant: \(constant)" //you may print whatever you want here
}
}
OBJECTIVE-C
#interface NSLayoutConstraint (Description)
#end
#implementation NSLayoutConstraint (Description)
-(NSString *)description {
return [NSString stringWithFormat:#"id: %#, constant: %f", self.identifier, self.constant];
}
#end
build it once again, and now you have more readable output for you:
once you got your id you can simple tap it in your Find Navigator:
and quickly find it:
HOW TO SIMPLE FIX THAT CASE?
try to change priority to 999 for broken constraint.
The problem you're having is the NSAutoresizingMaskLayoutConstraints should not be in there. This is the old system of springs and struts. To get rid of it, run this method on each view that you're wanting to constrain:
[view setTranslatesAutoresizingMaskIntoConstraints:NO];
Be careful, that you do not use more than one constraint in the same direction and type.
For example:
Vertical constraint for trailing = 15 and another one is >= 10.
Sometimes, Xcode creates some constraints you don't notice.
You have to get rid of redundant constraints and the log warning will surely disappear.
Additionaly, you can read and detect some certain reasons, directly from the log:
NSLayoutConstraint:0xa338390 V:|-(15)-[UILabel:0xa331260] (Names:
'|':UILabel:0xa330270 )>
This we can read as problem in UILabel constraint, it is leading vertical constraint being 15pt long.
NSLayoutConstraint:0x859ab20 H:-(13)-|[UIView:0x85a8fb0]...
This would be trailing horizontal constraint etc.
use swift this code
view.translatesAutoresizingMaskIntoConstraints = false
I had quite a number of these exceptions thrown, the fastest and easiest way I found to solve them was to find unique values in the exceptions which I then searched for in the storyboard source code. This helped me to find the actual view(s) and constraint(s) causing the problem (I use meaningful userLabels on all of the views, which makes it a lot easier to track the constraints and views)...
So, using the above exceptions I would open the storyboard as "source code" in xcode (or another editor) and look for something I can find...
<NSLayoutConstraint:0x72bf860 V:[UILabel:0x72bf7c0(17)]>
.. this looks like a vertical (V) constraint on a UILabel with a value of (17).
Looking through the exceptions I also find
<NSLayoutConstraint:0x72c22b0 V:[UILabel:0x72bf7c0]-(NSSpace(8))-[UIButton:0x886efe0]>
Which looks like the UILabel(0x72bf7c0) is close to a UIButton(0x886efe0) with some vertical spacing (8)..
That will hopefully be enough for me to find the specific views in the storyboard source code (probably by searching the text for "17" initially), or at least a few likely candidates. From there I should be able to actually figure out which views these are in the storyboard which will make it a lot easier to identify the problem (look for "duplicated" pinning or pinning that conflicts with size constraints).
I had a hard time figuring out what constraints were causing this error. Here is a simpler way to do it.
I'm using Xcode 6.1.1
"Command + A" to select all the UILabels, UIImages etc.
Click Editor -> Pin > (Select...) to Superview
again click Editor -> Resolve Auto Layout Issues -> Add Missing Constraints or Reset to Suggested Constraints. It depends on your case.
I had this issue because my .xib files were using autolayout.
In the file inspector, first tab. Unticking "Use Autolayout" solved the problem.
Here is my experience and Solution.
I didn't touched code
Select view (UILabel, UIImage etc)
Editor > Pin > (Select...) to Superview
Editor > Resolve Auto Layout Issues > Add Missing Constraints
I have followed SO questions and answers from each search query. But they all are related with specific one.
At the basic, I mean before you are going to write down a format (may be a simple one) it will gives you a warnings.
From iOS 8.0 by default views are size classes. Even if you disable size classes it will still contains some auto layout constraints.
So if you are planning to set constrains via code using VFL. Then you must take care of one below line.
// Remove constraints if any.
[self.view removeConstraints:self.view.constraints];
I had search a lot in SO, but the solution was lies in Apple Sample Code.
So you must have to remove default constraints before planning to add new one.
For me the main reason of this problem was that I forgot to uncheck AutoLayout in the Xib editor.
In fact, I did a lot of adjustments of the XIB in code.
for(UIView *view in [self.view subviews]) {
[view setTranslatesAutoresizingMaskIntoConstraints:NO];
}
This helped me catch the view causing the problem.
None of the foregoing answers is helpful in my situation. I am running XCode 10.1 and testing my app on the simulator for an "iPad (5th generation)". The simulator is running iOS 12.1.
I've got a simple root view in my storyboard, with two UITextField subviews. There are no constraints being used in the storyboard at all. And I have no UIButtonBarView objects in the app or the storyboard.
No messages get printed when the app launches and lays the root view out. None when the simulated device is rotated.
But in the simulator, the moment I click on one of the text fields, the keyboard extension arises from the bottom of the screen, although not the full keyboard, which never seems to show up in the simulator. But the following is printed out on the terminal:
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:0x6000034e7700 h=--& v=--& UIKeyboardAssistantBar:0x7f9c7d714af0.height == 0 (active)>",
"<NSLayoutConstraint:0x6000034aba20 V:|-(0)-[_UIUCBKBSelectionBackground:0x7f9c7d51ec70] (active, names: '|':_UIButtonBarButton:0x7f9c7d51de40 )>",
"<NSLayoutConstraint:0x6000034aba70 _UIUCBKBSelectionBackground:0x7f9c7d51ec70.bottom == _UIButtonBarButton:0x7f9c7d51de40.bottom (active)>",
"<NSLayoutConstraint:0x6000034fb3e0 V:|-(0)-[_UIButtonBarStackView:0x7f9c7d715880] (active, names: '|':UIKeyboardAssistantBar:0x7f9c7d714af0 )>",
"<NSLayoutConstraint:0x6000034fb750 V:[_UIButtonBarStackView:0x7f9c7d715880]-(0)-| (active, names: '|':UIKeyboardAssistantBar:0x7f9c7d714af0 )>",
"<NSLayoutConstraint:0x6000034abc00 'UIButtonBar.maximumAlignmentSize' _UIButtonBarButton:0x7f9c7d51de40.height == UILayoutGuide:0x600002ef4e00'UIViewLayoutMarginsGuide'.height (active)>",
"<NSLayoutConstraint:0x6000034d7cf0 'UIView-bottomMargin-guide-constraint' V:[UILayoutGuide:0x600002ef4e00'UIViewLayoutMarginsGuide']-(9)-| (active, names: '|':_UIButtonBarStackView:0x7f9c7d715880 )>",
"<NSLayoutConstraint:0x6000034d7c50 'UIView-topMargin-guide-constraint' V:|-(10)-[UILayoutGuide:0x600002ef4e00'UIViewLayoutMarginsGuide'] (active, names: '|':_UIButtonBarStackView:0x7f9c7d715880 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x6000034aba70 _UIUCBKBSelectionBackground:0x7f9c7d51ec70.bottom == _UIButtonBarButton:0x7f9c7d51de40.bottom (active)>
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.
It certainly appears to me that all this has to do with nothing in my app, and everything to do with how Apple is creating its own keyboard view, even with my small extension declared to be combined with it.
So the question remains, is there something I as an app developer am responsible for doing (on the presumption this is a bunch of stuff worth attending to) or is it just Apple's own problem/bug?
FWIW, this constraint problem message doesn't occur when simulating a newer iPad model, such as the iPad Pro 12.9-inch (3rd generation). But the message does show up when simulating an iPad Pro 9.7-inch". All claiming they're running iOS 12.1.
I am getting this same error, but only on a specific view, when I touch the first textfield, and then the next textfield down.
I am writing in SwiftUI for iOS 13.4
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.
(
"<NSLayoutConstraint:0x2809b6760 'assistantHeight' TUISystemInputAssistantView:0x105710da0.height == 44 (active)>",
"<NSLayoutConstraint:0x2809ccff0 'assistantView.bottom' TUISystemInputAssistantView:0x105710da0.bottom == _UIKBCompatInputView:0x10525ae10.top (active)>",
"<NSLayoutConstraint:0x2809cccd0 'assistantView.top' V:|-(0)-[TUISystemInputAssistantView:0x105710da0] (active, names: '|':UIInputSetHostView:0x105215010 )>",
"<NSLayoutConstraint:0x2809ca300 'inputView.top' V:|-(0)-[_UIKBCompatInputView:0x10525ae10] (active, names: '|':UIInputSetHostView:0x105215010 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x2809ccff0 'assistantView.bottom' TUISystemInputAssistantView:0x105710da0.bottom == _UIKBCompatInputView:0x10525ae10.top (active)>
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.
One thing to watch out for (at least this tripped me up) was that I was removing the constraint from the wrong view. The constraint I was trying to remove was not a child constraint of my view so when I did
myView.removeConstraint(theConstraint)
it wasn't actually removing anything because I needed to call
myView.superView.removeConstraint(theConstraint)
since the constraint was technically sibling constraint of my view.
I was also getting the same issue of breaking constraints in the log, for a viewCircle in the xib. I almost tried everything listed above and nothing was working for me.
Then I tried to change the priority of the Height constraint which was breaking in the log(confirmed by adding an identifiers for the constraints on the xib)enter image description here
Basically, you just have to remove that constraint from the associated view. For instance, if is the height constraint giving warning, just remove it from your view; it will not affect the view.
swift 4
I just add this line in viewDidLoad and work fine with me.
view.removeConstraints(view.constraints)