CODEWITHSUNDEEP
iosswiftautolayout
Afsara
Afsara

Reputation: 1461

Set Leading space to UIView , Crashes in swift

I need to modify leading space of a View . here is my code 

    let advSearchViewAddLeadingConstraint: NSLayoutConstraint = NSLayoutConstraint(
        item:advancedSearchView,
        attribute:NSLayoutAttribute.Leading,
        relatedBy:NSLayoutRelation.Equal,
        toItem:self.view, 
        attribute:NSLayoutAttribute.NotAnAttribute,
        multiplier:0,
        constant:200)
        self.view.addConstraint(advSearchViewAddLeadingConstraint)

By using this code i am getting crash as

* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* +[NSLayoutConstraint constraintWithItem:attribute:relatedBy:toItem:attribute:multiplier:constant:]: Unknown layout attribute'

Upvotes: 1

Views: 1835

Answers (2)

user3307029
user3307029

Reputation: 87

I would work at it the other way around. Create a containing view and drag an IBOutlet for leading space constraint. Then just change the constant, it should work better.

leadingConstraint.constant = 200
self.view.layoutIfNeeded()

Upvotes: 1

Zev Eisenberg
Zev Eisenberg

Reputation: 8148

You probably want NSLayoutAttribute.Leading instead of NSLayoutAttribute.NotAnAttribute. If you're providing two items, you need to specify the attribute of each item:

let advSearchViewAddLeadingConstraint: NSLayoutConstraint =
    NSLayoutConstraint(
        item:advancedSearchView,
        attribute:NSLayoutAttribute.Leading,
        relatedBy:NSLayoutRelation.Equal,
        toItem:self.view, 
        attribute:NSLayoutAttribute.Leading,
        multiplier:0,
        constant:200)

A couple of other notes:

  • You can activate the constraint with: advSearchViewAddLeadingConstraint.active = true

  • In Swift, type inference can help you out with enum types, so instead of typing NSLayoutAttribute.Leading you can just type Leading.

Upvotes: 0

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