Prevent Interface Builder from auto creating Const

I created a demo project here. I have a view where I created a ScrollView in a .xib file. In interface builder I did not set any constraints. In my viewDidLoad method I set constraints with SnapKit:

scrollView.snp_makeConstraints { (make) -> Void in
  make.edges.equalTo(self.view)
}

When I run the code I get the following console output:

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) 
(
    "<NSIBPrototypingLayoutConstraint:0x7b74e280 'IB auto generated at build time for view with fixed frame' V:|-(1)-[UIScrollView:0x7b74c430]   (Names: '|':UIView:0x7b74dd10 )>",
    "<<DeviceImagesTest.LayoutConstraint:0x7baa2760> <UIScrollView:0x7b6608d0>.top == <UIView:0x7b64d800>.top>"
)

Will attempt to recover by breaking constraint 
<NSIBPrototypingLayoutConstraint:0x7b74e280 'IB auto generated at build time for view with fixed frame' V:|-(1)-[UIScrollView:0x7b74c430]   (Names: '|':UIView:0x7b74dd10 )>

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.
2015-05-29 18:37:14.368 DeviceImagesTest[36462:607] 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) 
(
    "<NSIBPrototypingLayoutConstraint:0x7b74e080 'IB auto generated at build time for view with fixed frame' H:|-(0)-[UIScrollView:0x7b74c430](LTR)   (Names: '|':UIView:0x7b74dd10 )>",
    "<NSIBPrototypingLayoutConstraint:0x7b74e330 'IB auto generated at build time for view with fixed frame' H:[UIScrollView:0x7b74c430(600)]>",
    "<<DeviceImagesTest.LayoutConstraint:0x7baa7170> <UIScrollView:0x7baa7b30>.right == <UIView:0x7baa79a0>.right>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa4800 h=-&- v=-&- UIView:0x7b74dd10.width == UIViewControllerWrapperView:0x7ba9f060.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa5180 h=-&- v=-&- UIViewControllerWrapperView:0x7ba9f060.width == UINavigationTransitionView:0x7bc769b0.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa58e0 h=-&- v=-&- UINavigationTransitionView:0x7bc769b0.width == UILayoutContainerView:0x7bc75140.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa61a0 h=-&- v=-&- UILayoutContainerView:0x7bc75140.width == UIWindow:0x7bc71870.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa69a0 h=--- v=--- H:[UIWindow:0x7bc71870(320)]>"
)

Will attempt to recover by breaking constraint 
<<DeviceImagesTest.LayoutConstraint:0x7baa95b0> <UIScrollView:0x7baa9610>.right == <UIView:0x7baa96b0>.right>

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.
2015-05-29 18:37:14.496 DeviceImagesTest[36462:607] 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) 
(
    "<NSIBPrototypingLayoutConstraint:0x7b74e360 'IB auto generated at build time for view with fixed frame' V:[UIScrollView:0x7b74c430(600)]>",
    "<<DeviceImagesTest.LayoutConstraint:0x7bc77e40> <UIScrollView:0x7bc7f6a0>.top == <UIView:0x7bc52180>.top>",
    "<<DeviceImagesTest.LayoutConstraint:0x7bc49420> <UIScrollView:0x7bc74b00>.bottom == <UIView:0x7bc7b970>.bottom>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa4960 h=-&- v=-&- UIView:0x7b74dd10.height == UIViewControllerWrapperView:0x7ba9f060.height>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa51e0 h=-&- v=-&- UIViewControllerWrapperView:0x7ba9f060.height == UINavigationTransitionView:0x7bc769b0.height>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa5940 h=-&- v=-&- UINavigationTransitionView:0x7bc769b0.height == UILayoutContainerView:0x7bc75140.height>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa6200 h=-&- v=-&- UILayoutContainerView:0x7bc75140.height == UIWindow:0x7bc71870.height>",
    "<NSAutoresizingMaskLayoutConstraint:0x7baa69d0 h=--- v=--- V:[UIWindow:0x7bc71870(568)]>"
)

Will attempt to recover by breaking constraint 
<<DeviceImagesTest.LayoutConstraint:0x7bc84790> <UIScrollView:0x7bc848b0>.bottom == <UIView:0x7bc84860>.bottom>

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.

It seems that Interface Builder is generating Constraints for me even if I did not set any. This leads to a conflict with my constraints I set in code. I also set setTranslatesAutoresizingMasks(false).

How can I prevent Interface Builder from auto generating constraints?

回答1:

If you are confused about the NSAutoresizingMaskLayoutConstraints in that list, it might be because you haven't called setTranslatesAutoresizingMasksIntoContraints(false) on that view. (although, I was under the impression that SnapKit does that for you).

If you are confused about the NSIBPrototypingLayoutConstraint, that's an auto-generated constraint by Interface Builder. To get rid of it, add some Top, Bottom, Leading and Trailing constraints in Interface Builder and set them to be removed at build time. For more details about that, have a look at http://travisjeffery.com/b/2013/11/preventing-ib-auto-generated-at-build-time-for-view-with-fixed-frame/

UPDATE: url was changed to http://travisjeffery.com/b/2013/11/preventing-ib-auto-generated-at-build-time-for-view-with-fixed-frame-when-using-auto-layout/

回答2: