How to access extension of UIColor in Swift?

Question

I am very new to swift and trying to create an extension of UIColor class as

extension UIColor{

    func getCustomBlueColor() -> UIColor {
        retur         


        

Answer 1

Get the this extension for customize type UIView

extension UIColor {
    // Method returns a custom color
    static func rgb(red: CGFloat, green: CGFloat, blue: CGFloat) -> UIColor {
        return .init(red: blue / 255, green: green / 255, blue: blue / 255, alpha: 1.0)
    }
}

Answer 2

With Swift 3, predefined UIColors are used accordingly:

var myColor: UIColor = .white // or .clear or whatever

Therefore, if you want something similar, such as the following...

var myColor: UIColor = .myCustomColor

...then, you would define the extension like so:

extension UIColor {

    public class var myCustomColor: UIColor {
        return UIColor(red: 248/255, green: 248/255, blue: 248/255, alpha: 1.0)
    }

}

In fact, Apple defines white as:

public class var white: UIColor

Answer 3

You defined a instance function. It means you need an instance of UIColor in case to use getCustomBlueColor()-method.

It looks like you want to have a class method, instead of the instance method. So you have to change your definition like this:

extension UIColor{
    class func getCustomBlueColor() -> UIColor{
        return UIColor(red:0.043, green:0.576 ,blue:0.588 , alpha:1.00)
    }
}

Note the 'class' before func, so the method is now accessible as a class method.

The same story using class methods in a structure:

struct MyColors{
    static func getCustomBlueColor() -> UIColor{
        return UIColor(red:0.043, green:0.576 ,blue:0.588 , alpha:1.00)
    }
}
let color = MyColors.getCustomBlueColor()

If you just want to have a class with some color definitions, I recommend you to use a struct over a class or extension:

struct MyColors{
    static var getCustomBlueColor = { return UIColor(red:0.043, green:0.576 ,blue:0.588 , alpha:1.00) }
}
let color = MyColors.getCustomBlueColor()