iPhone SDK convert hex color string to UIColor

This function will help you to convert hex color string to UIColor

Class.h

+ (UIColor *) colorWithHexString: (NSString *) stringToConvert;

1	+ (UIColor ) colorWithHexString: (NSString ) stringToConvert;

Class.m

+ (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];
}

+ (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];

}

4 Comments

Andy October 15, 2010 at 11:07 pm

Here's something along those lines, but more concise: #define TEST_COLOR @"#f73e0a" unsigned int c; if ([TEST_COLOR characterAtIndex:0] == '#') { [[NSScanner scannerWithString:[TEST_COLOR substringFromIndex:1]] scanHexInt:&c]; } else { [[NSScanner scannerWithString:TEST_COLOR] scanHexInt:&c]; } img.backgroundColor = [UIColor colorWithRed:((c & 0xff0000) >> 16)/255 green:((c & 0xff00) >> 8)/255 blue:(c & 0xff)/255 alpha:1.0];
Andy October 15, 2010 at 11:10 pm

Oh, forgot... To ensure float, add .0 to the ends of the /255 parts.
Andy October 15, 2010 at 11:32 pm

Sorry. I should have just copied our category in (which anyone can rename to whatever they want, of course): #import @interface NSString (meltutils) - (UIColor *)toUIColor; @end @implementation NSString (meltutils) - (UIColor *)toUIColor { unsigned int c; if ([self characterAtIndex:0] == '#') { [[NSScanner scannerWithString:[self substringFromIndex:1]] scanHexInt:&c]; } else { [[NSScanner scannerWithString:self] scanHexInt:&c]; } return [UIColor colorWithRed:((c & 0xff0000) >> 16)/255.0 green:((c & 0xff00) >> 8)/255.0 blue:(c & 0xff)/255.0 alpha:1.0]; } @end Then just use like this (I have the above interface and implementation stored in NSString+meltutils.h and NSString+meltutils.m): #import "NSString+meltutils.h" ... UIColor *aColorStr = [@"#f82a01" toUIColor]; ... Maybe that will help someone out. :)

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iPhone SDK convert hex color string to UIColor

4 Comments