How can I obtain a CGColor from RGB values?

Question

I am trying to create a custom RGB CGColor using Swift to use as a border color for a UIButton . I've tried following code but the color is not visible:

var red = UIColor(red: 100.0, green: 130.0, blue: 230.0, alpha: 1.0)
self.layer.borderColor = red.CGColor

Is there any way to create a CGColor directly from RGB values?

Answer 1

You have to give the values between 0 and 1.0. So divide the RGB values by 255.

Change Your code to

var red = UIColor(red: 100.0/255.0, green: 130.0/255.0, blue: 230.0/255.0, alpha: 1.0)
self.layer.borderColor = red.CGColor

Answer 2

您可以在 Swift 3 中将其缩减为一行：

avLayer.backgroundColor = UIColor.red.CGColor

Answer 3

On Mac OS X there is CGColorCreateGenericRGB() , but it doesn't exist on iOS. You can use CGColorCreate with appropriate parameters, though.

self.layer.borderColor = CGColorCreate(CGColorSpaceCreateDeviceRGB(), [1.0, 0.5, 0.5, 1.0])

The values in the array are, in order of appearance: red, green, blue, and alpha. Just like UIColor :)

https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGColor/#//apple_ref/c/func/CGColorCreate

Answer 4

UImage *newImage = [self imageWithColor:[UIColor colorWithRed:200/255. green:228/255. blue:194/255. alpha:0.99]];

Answer 5

Maybe all you need is set the borderWidth , by default it is 0, so it is not visible:

self.layer.borderWidth = 1.0

Just in case you can set the cornerRadius if you need it rounded ... might be useful ;-)

self.layer.cornerRadius = 4.0