Adding a custom category - Obj C

Question

I am having trouble adding my custom uicolor

I have a .h and a .m file, both named custcolors

Here is what my custColors.h file looks like:

#import <UIKit/UIKit.h>

@interface UIColor (MyCatagory)
+ (UIColor*) customRedColor;
@end

Here is what my custColors.m file looks like:

#import "custColors.h"

@implementation UIColor (MyCategory)

+ (UIColor *)customRedColor {
    return [UIColor colorWithHexString:@"88C800"];
}
-(UIColor*)colorWithHexString:(NSString*)hex
{
    NSString *cString = [[hex stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];

    // String should be 6 or 8 characters
    if ([cString length] < 6) return [UIColor grayColor];

    // strip 0X if it appears
    if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];

    if ([cString length] != 6) return  [UIColor grayColor];

    // Separate into r, g, b substrings
    NSRange range;
    range.location = 0;
    range.length = 2;
    NSString *rString = [cString substringWithRange:range];

    range.location = 2;
    NSString *gString = [cString substringWithRange:range];

    range.location = 4;
    NSString *bString = [cString substringWithRange:range];

    // Scan values
    unsigned int r, g, b;
    [[NSScanner scannerWithString:rString] scanHexInt:&r];
    [[NSScanner scannerWithString:gString] scanHexInt:&g];
    [[NSScanner scannerWithString:bString] scanHexInt:&b];

    return [UIColor colorWithRed:((float) r / 255.0f)
                           green:((float) g / 255.0f)
                            blue:((float) b / 255.0f)
                           alpha:1.0f];
}

@end

My issue is that when I try to use this I just get an error. Saying;

custColors.h:12:33: Expected identifier
custColors.h:12:35: Expected an Objective-C directive after '@'
custColors.m
custColors.m:13:51: Use of undeclared identifier 'hex'

What I am trying to do is create a custom hex color that I can use to be able to implement into every view controller to change it's background color to this.

Suggestions, thoughts?

Answer 1

It appears that colorWithHexString should be a class method, not an instance method. Change it to:

+ (UIColor*)colorWithHexString:(NSString*)hex {

    ...
}