UIColor 16进制

首先创建一个UIColor的类目;

+ (UIColor *)RGBFromHexColor:(NSString *)hexColor
{
    NSString *cString = [[hexColor stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    if ([cString length] < 6) {
        return [UIColor clearColor];
    }
    if ([cString hasPrefix:@"0X"])
        cString = [cString substringFromIndex:2];
    if ([cString hasPrefix:@"#"])
        cString = [cString substringFromIndex:1];
    if ([cString length] != 6)
        return [UIColor clearColor];
    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];
    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];
}