CODEWITHSUNDEEP
iosswiftswift3
Useruuu
Useruuu

Reputation: 145

Instance member cannot be used when its already declared

I'm declaring UIColors in an extension: UIColor file but I keep getting error like "instance member 'red' cannot be used on type 'UIColor', when I declared it already in the extension file. I will list a picture of the error and the code below.

Error image

Extension UIColor File 

import Foundation
import UIKit

  extension UIColor {

var red: CGFloat {
    get {
        let components = self.cgColor.components
        return components![0]
    }
}

var green: CGFloat {
    get {
        let components = self.cgColor.components
        return components![1]
    }
}

var blue: CGFloat {
    get {
        let components = self.cgColor.components
        return components![2]
    }
}

var alpha: CGFloat {
    get {
        return self.cgColor.alpha
    }
}

func alpha(_ alpha: CGFloat) -> UIColor {
    return UIColor(red: self.red, green: self.green, blue: self.blue, alpha: alpha)
}

func white(_ scale: CGFloat) -> UIColor {
    return UIColor(
        red: self.red + (1.0 - self.red) * scale,
        green: self.green + (1.0 - self.green) * scale,
        blue: self.blue + (1.0 - self.blue) * scale,
        alpha: 1.0
    )
}
 }

Swift file where I would like to use one of the colors. 

var color: UIColor = UIColor.red {
    didSet {
        setup()
    }
}

Upvotes: 1

Views: 648

Answers (1)

rmaddy
rmaddy

Reputation: 318774

The red, green, and blue property names you added in your extension conflict with the class variables of the same names. Rename the properties in your extension.

FYI - there is no need for your alpha method in your extension. UIColor already provides the same method (named withAlphaComponent).

And your implementation of red, green, and blue may crash. You are assuming the CGColor always has 3 components and you assume it is an RGB color. Neither case is always true.

Upvotes: 2

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