ios - Color Variables in Objective C

Question

How do I set and reuse a color variable in Obj C? I am trying to set a reusable color value as in this question:

Change background color with a variable iOS

but am unsuccessful.

 UIColor *lightGrayHeader = [UIColor colorWithRed:246/255.f green:239/255.f blue:239/255.f alpha:1.0];

 self.view.backgroundColor = [UIColor lightGrayHeader];

Returns an error: "Initializer element is not a compile-time constant."

Thanks for your ideas!

Answer 1

What you have defined is a local variable. It is used like this:

UIColor *lightGrayHeader = [UIColor colorWithRed:246/255.f green:239/255.f blue:239/255.f alpha:1.0];
self.view.backgroundColor = lightGrayHeader;

If you want to use a static method on UIColor to fetch a colour, you could do this:

@interface UIColor (MyColours)
+ (instancetype)lightGrayHeader;
@end

@implementation UIColor (MyColours)
+ (instancetype)lightGrayHeader {
  return [self  colorWithRed:246/255.f green:239/255.f blue:239/255.f alpha:1.0];
}
@end

And then as long as you import the UIColor (MyColours) header, you could use:

self.view.backgroundColor = [UIColor lightGrayHeader];