How do I create a 1px line in Interface Builder?

ios uikit interface-builder retina-display
i_am_jorf picture i_am_jorf · May 15, 2014 · Viewed 19k times · Source

Note, I'm looking to make a 1px line, not a 1pt line. Meaning it should be 1px regardless of screen scale (so 0.5pt on Retina devices).

I can do this programmatically, but can I do it in the Interface Builder? For example I cannot set a UIView to have a height of less than 1.

If I can do it in IB then I don't have to declare an outlet and manually set the frame in awakeFromNib.

Answer

Daniel Galasko picture Daniel Galasko · Nov 11, 2014

Just in case someone else comes here wanting to know how it can be done programmatically, heres how you do it:

Interface Builder

Make a height constraint in IB to the desired view and set the constant to 1.

enter image description here

Then you will need to CTRL+Drag from the constraint into your custom view or ViewController.

Whenever the Xib is loaded, be it in awakeFromNib or viewDidLoad, you are going to set the constant of the constraint to the scale of the display:

Swift

onePixelViewHeightConstraint.constant = 1/UIScreen.main.scale//enforces it to be a true 1 pixel line

Objective-C

self.onePixelViewHeightConstraint.constant = 1.f/[UIScreen mainScreen].scale;//enforces it to be a true 1 pixel line

Enjoy

Related questions

Vertically align text to top within a UILabel

I have a UILabel with space for two lines of text. Sometimes, when the text is too short, this text is displayed in the vertical center of the label. How do I vertically align the text to always be at …

Read More
How to get the screen width and height in iOS?

How can one get the dimensions of the screen in iOS? Currently, I use: lCurrentWidth = self.view.frame.size.width; lCurrentHeight = self.view.frame.size.height; in viewWillAppear: and willAnimateRotationToInterfaceOrientation:duration: The first time I get the entire screen size. …

Read More
How do I size a UITextView to its content?

Is there a good way to adjust the size of a UITextView to conform to its content? Say for instance I have a UITextView that contains one line of text: "Hello world" I then add another line of text: "Goodbye …

Read More