CODEWITHSUNDEEP
uiviewswift3gradient
Carl Henretti
Carl Henretti

Reputation: 477

CAGradientLayer doesn't appear (Swift 3)

I'm making a weather app and for showing maximum and minimum temperature of the day, I'm using a UIView that's corners I've rounded by using .layer.cornerRadius. Now I want to add a gradient layer with different colors (symbolizing temperature), but the gradientLayer doesn't appear. Here's my viewDidLoad(), the views name is currentMinMaxTemperatureView:

let gradientLayer = CAGradientLayer()
    gradientLayer.frame = currentMinMaxTemperatureView.bounds
    gradientLayer.cornerRadius = currentMinMaxTemperatureView.cornerRadius
    gradientLayer.colors = [UIColor.blue, UIColor.yellow, UIColor.red]
    currentMinMaxTemperatureView.layer.addSublayer(gradientLayer)

Why doesn't it appear? When running this, my view looks like this:

enter image description here

Upvotes: 1

Views: 1377

Answers (2)

KLD
KLD

Reputation: 160

There are a couple of problems with your code:

First, as @archLucifer mentioned, CAGradientLayer expects CGColor, not UIColor.

Simply convert your colours like so: 

[UIColor.blue.cgColor, UIColor.yellow.cgColor, UIColor.red.cgColor]

Second, you want to make sure you add your gradient after your currentMinMaxTemperatureView is added to the superview. Otherwise, its bounds will be nil.

Try adding the gradient later in your UIViewController lifecycle, like ViewDidLayoutSubviews()

Upvotes: 5

archLucifer
archLucifer

Reputation: 389

Try the following

gradientLayer.colors = [UIColor.blue.cgColour, UIColor.yellow.cgColour, UIColor.red.cgColour]

Upvotes: 3

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