hex color from uicolor

Question

i have a problem in converting uicolor to hex color, here what i found

CGColorRef colorref = [[Colorview_ backgroundColor] CGColor];

int numComponents = CG         


        

Answer 1

I tried that yesterday because I had to get a hex color from a uicolor and made it work in javascript too, but this doesn't work when a component is 0, because it gets a 0 instead of a 00. So a pure cyan would be RGB 0 255 255, and this code would return #0ffff instead of #00ffff.

I made this code from yours, and it's working on my app:

-(NSString*)colorToHex:(UIColor*)color{

    CGColorRef colorref = [color CGColor];

    const CGFloat *components = CGColorGetComponents(colorref);

    NSString *hexString = @"#";
    int hexValue = 0;

    for (int i=0; i<3; i++) {
        if (components[i] == 0) {
            hexString = [NSString stringWithFormat:@"%@00", hexString];
        }else{
            hexValue = 0xFF*components[i];
            hexString = [NSString stringWithFormat:@"%@%x", hexString, hexValue];
        }
    }

    return hexString;
}

Answer 2

NSString *hexString = [NSString stringWithFormat:@"#%d", hexValue];

You are formatting it as a digit with %d

You want to format it as hex with %x or %X -- maybe as string %s I didnt check what the function is doing and what int hexValue is holding

d or i Signed decimal integer 392

x Unsigned hexadecimal integer 7fa

X Unsigned hexadecimal integer (capital letters) 7FA

Answer 3

The sylphos answer above doesnt work for darkGrayColor.

This works better (taken from http://softteco.blogspot.jp/2011/06/extract-hex-rgb-color-from-uicolor.html):

- (NSString *) hexFromUIColor:(UIColor *)color {
    if (CGColorGetNumberOfComponents(color.CGColor) < 4) {
        const CGFloat *components = CGColorGetComponents(color.CGColor);
        color = [UIColor colorWithRed:components[0] green:components[0] blue:components[0] alpha:components[1]];
    }
    if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) != kCGColorSpaceModelRGB) {
        return [NSString stringWithFormat:@"#FFFFFF"];
    }
    return [NSString stringWithFormat:@"#%02X%02X%02X", (int)((CGColorGetComponents(color.CGColor))[0]*255.0), (int)((CGColorGetComponents(color.CGColor))[1]*255.0), (int)((CGColorGetComponents(color.CGColor))[2]*255.0)];
}

Answer 4

Here is a version of this, but formatted as a C function:

static inline NSString *hexFromUIColor(UIColor * _color) {
    if (CGColorGetNumberOfComponents(_color.CGColor) < 4) {
        const CGFloat *components = CGColorGetComponents(_color.CGColor);
        _color = [UIColor colorWithRed:components[0] green:components[0] blue:components[0] alpha:components[1]];
    }
    if (CGColorSpaceGetModel(CGColorGetColorSpace(_color.CGColor)) != kCGColorSpaceModelRGB) {
        return [NSString stringWithFormat:@"#FFFFFF"];
    }
    return [NSString stringWithFormat:@"#%02X%02X%02X", (int)((CGColorGetComponents(_color.CGColor))[0]*255.0), (int)((CGColorGetComponents(_color.CGColor))[1]*255.0), (int)((CGColorGetComponents(_color.CGColor))[2]*255.0)];
}