[iOS] CGContextSetRGBStrokeColor 색깔 Setting하기

Object-C Style

CGFloat red, green, blue, alpha;
red = 1.0f;
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), red, green, blue, alpha);

//or
CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [[UIColor redColor] CGColor]);

Swift Style

let myUIColor = UIColor.purpleColor()
var r:CGFloat, g:CGFloat, b:CGFloat, a:CGFloat = 0
myUIColor.getRed(&r, green: &g, blue: &b, alpha: &a)
CGContextSetRGBStrokeColor(c, r, g, b, a)

// or
CGContextSetStrokeColorWithColor(myUIColor.CGColor);