How to set the UILabel's UIColor from a Plist - objective-c

Question

the question is in the title, How to set the UILabel's UIColor from a Plist ?
i tried this :
UIColor *colorLabel;
i add a NSString row in my Plist, and wrote redColor as a value but doesnt work...
How can i handle it ?
Thanks guys.

Answer 1

I would personally store the RGBA values instead of a string and then you can just use
+ (UIColor *)colorWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha
Do not do the below
Just as an interesting side note the most inflexible way would be to use the UIColor convenience methods like this
[UIColor performSelector:NSSelectorFromString(#"redColor")]

Answer 2

I think you need convert from string to an UIColor. You put colors into your plist by hex-colors (for red - ff0000) and then use something like following function for get UIColor.
+ (UIColor *) colorWithHexString: (NSString *) stringToConvert
{
    NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    // String should be 6 or 8 characters
    if ([cString length] < 6) return [UIColor blackColor];
    // strip 0X if it appears
    if ([cString hasPrefix:#"0X"]) cString = [cString substringFromIndex:2];
    if ([cString length] != 6) return [UIColor blackColor];
    // 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];
}

Answer 3

To preserve human readability, I did a category for this:
#implementation UIColor (EPPZRepresenter)
NSString *NSStringFromUIColor(UIColor *color)
{
const CGFloat *components = CGColorGetComponents(color.CGColor);
return [NSString stringWithFormat:#"[%f, %f, %f, %f]",
components[0],
components[1],
components[2],
components[3]];
}
UIColor *UIColorFromNSString(NSString *string)
{
NSString *componentsString = [[string stringByReplacingOccurrencesOfString:#"[" withString:#""] stringByReplacingOccurrencesOfString:#"]" withString:#""];
NSArray *components = [componentsString componentsSeparatedByString:#", "];
return [UIColor colorWithRed:[(NSString*)components[0] floatValue]
green:[(NSString*)components[1] floatValue]
blue:[(NSString*)components[2] floatValue]
alpha:[(NSString*)components[3] floatValue]];
}
#end
The same formatting that is used by NSStringFromCGAffineTransform. This is actually a part of a bigger scale plist object representer in eppz!kit at GitHub.