CODEWITHSUNDEEP
iosobjective-cautolayout
jdog
jdog

Reputation: 10769

Using Autolayout in IB how do I position a UIView in the center of the screen programmatically?

I have a UIView that I would like to center horizontally over the main view and then center vertically over the main view, minus about 14 pixels.

If I set it up with IB it works on the Retina 3.5, but when running on Retina 4 it is of course off by roughly 40 pixels.

I am thinking the best solution is establishing these constraints programmatically based on screen height?

Upvotes: 2

Views: 2664

Answers (3)

sarawanak
sarawanak

Reputation: 439

You don't need to set constraints programmatically to align a view to horizontal & vertical center of the screen. It can be done via Interface builder itself. However, you still can set constraints using NSLayoutAnchor apis in code, like the below example. NSLayoutAnchor apis are simple, elegant and, concise. And are available since iOS 9.

myView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor)
myView.centerYAnchor.constraint(equalTo: self.view.centerYAnchor)

Upvotes: 1

rdelmar
rdelmar

Reputation: 104092

Use the centerX and centerY constants, and put in a constant of 14 (or -14 not sure which way you want it to be),

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.view attribute:NSLayoutAttributeCenterX relatedBy:0 toItem:view attribute:NSLayoutAttributeCenterX multiplier:1 constant:0]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.view attribute:NSLayoutAttributeCenterY relatedBy:0 toItem:view attribute:NSLayoutAttributeCenterY multiplier:1 constant:14]];

Upvotes: 10

Asif Bilal
Asif Bilal

Reputation: 4369

In order to make your view in Center(Horizontally & Vertically). Select the view in Interface Builder, then from Top Menu, Select Editor> Align> Horizontal Center in Container/ Vertical Center in Container.

You can also add more constraints to satisfy view's Geometry.

Upvotes: 1

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