CODEWITHSUNDEEP
iosswiftuitableviewautolayout
sarah
sarah

Reputation: 1221

autolayout constraints not working correctly when adding them programmatically

this is my view

enter image description here

the black area is a view, called containerView that has the following constrains

enter image description here

i want to add a uitableView to it dyrnamically, i did this:

 func setConstraintsForTableView(tableView: UITableView){

        self.containerView.addSubview(tableView)

        let bottomConstraint = tableView.bottomAnchor.constraintEqualToAnchor(self.containerView.bottomAnchor)
        let leftConstraint = tableView.leftAnchor.constraintEqualToAnchor(self.containerView.leftAnchor)
        let rightConstraint = tableView.rightAnchor.constraintEqualToAnchor(self.containerView.rightAnchor)
        let topConstraint = tableView.topAnchor.constraintEqualToAnchor(self.containerView.topAnchor)
        self.containerView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activateConstraints([bottomConstraint, leftConstraint, rightConstraint, topConstraint])

        self.containerView.layoutIfNeeded()

    }

but i got this in the log:

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:0x7fe8c9c2ddb0 h=--& v=--& UITableView:0x7fe8cd05c200.midX == + 120>",
    "<NSLayoutConstraint:0x7fe8c9e97340 UIView:0x7fe8c9e8aeb0.trailingMargin == UIView:0x7fe8cb304490.trailing>",
    "<NSLayoutConstraint:0x7fe8c9e97390 UIView:0x7fe8cb304490.leading == UIView:0x7fe8c9e8aeb0.leadingMargin>",
    "<NSLayoutConstraint:0x7fe8c9c2cf70 H:|-(0)-[UITableView:0x7fe8cd05c200](LTR)   (Names: '|':UIView:0x7fe8cb304490 )>",
    "<NSLayoutConstraint:0x7fe8c9c2d0c0 UITableView:0x7fe8cd05c200.right == UIView:0x7fe8cb304490.right>",
    "<NSLayoutConstraint:0x7fe8cb104c40 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7fe8c9e8aeb0(375)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x7fe8c9c2d0c0 UITableView:0x7fe8cd05c200.right == UIView:0x7fe8cb304490.right>

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.
2015-12-19 22:12:16.201 GrabATable[2419:218311] 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) 
(
    "<_UILayoutSupportConstraint:0x7fe8cb036c70 V:[_UILayoutGuide:0x7fe8c9e956a0(20)]>",
    "<_UILayoutSupportConstraint:0x7fe8cb0365c0 V:|-(0)-[_UILayoutGuide:0x7fe8c9e956a0]   (Names: '|':UIView:0x7fe8c9e8aeb0 )>",
    "<_UILayoutSupportConstraint:0x7fe8cb0363d0 V:[_UILayoutGuide:0x7fe8c9e96410(0)]>",
    "<_UILayoutSupportConstraint:0x7fe8cb018490 _UILayoutGuide:0x7fe8c9e96410.bottom == UIView:0x7fe8c9e8aeb0.bottom>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fe8c9c2de50 h=--& v=--& UITableView:0x7fe8cd05c200.midY == + 64>",
    "<NSLayoutConstraint:0x7fe8c9e97070 UIImageView:0x7fe8c9e8a160.height == 0.33*UIView:0x7fe8c9e8aeb0.height>",
    "<NSLayoutConstraint:0x7fe8c9e97110 V:[_UILayoutGuide:0x7fe8c9e956a0]-(0)-[UIImageView:0x7fe8c9e8a160]>",
    "<NSLayoutConstraint:0x7fe8c9e972f0 V:[UIImageView:0x7fe8c9e8a160]-(20)-[UIView:0x7fe8cb304490]>",
    "<NSLayoutConstraint:0x7fe8c9e973e0 V:[UIView:0x7fe8cb304490]-(0)-[_UILayoutGuide:0x7fe8c9e96410]>",
    "<NSLayoutConstraint:0x7fe8c9c2cc50 UITableView:0x7fe8cd05c200.bottom == UIView:0x7fe8cb304490.bottom>",
    "<NSLayoutConstraint:0x7fe8c9c2d210 V:|-(0)-[UITableView:0x7fe8cd05c200]   (Names: '|':UIView:0x7fe8cb304490 )>",
    "<NSLayoutConstraint:0x7fe8cb104c90 'UIView-Encapsulated-Layout-Height' V:[UIView:0x7fe8c9e8aeb0(667)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x7fe8c9c2cc50 UITableView:0x7fe8cd05c200.bottom == UIView:0x7fe8cb304490.bottom>

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.

Upvotes: 2

Views: 2822

Answers (1)

Peter Hornsby
Peter Hornsby

Reputation: 4266

Output of interest:

 "<NSAutoresizingMaskLayoutConstraint:0x7fe8c9c2ddb0 h=--& v=--& UITableView:0x7fe8cd05c200.midX == + 120>",

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x7fe8c9c2d0c0 UITableView:0x7fe8cd05c200.right == UIView:0x7fe8cb304490.right>

You need to set translatesAutoresizingMaskIntoConstraints to false on the tableView. See the UIView class Reference for more detail.

tableView.translatesAutoresizingMaskIntoConstraints = false

From the UIView Class Reference:

Discussion

If this property’s value is true, the system creates a set of constraints that duplicate the behavior specified by the view’s autoresizing mask. This also lets you modify the view’s size and location using the view’s frame, bounds, or center properties, allowing you to create a static, frame-based layout within Auto Layout.

Note that the autoresizing mask constraints fully specify the view’s size and position; therefore, you cannot add additional constraints to modify this size or position without introducing conflicts. If you want to use Auto Layout to dynamically calculate the size and position of your view, you must set this property to false, and then provide a non ambiguous, nonconflicting set of constraints for the view.

By default, the property is set to true for any view you programmatically create. If you add views in Interface Builder, the system automatically sets this property to false.

Upvotes: 4

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