目录
1 uint   类型 0xFFFFFF
2 string 类型 #FFFFFF

1.uint类型 0xFFFFFF

+ (UIColor *)colorWithRGBValue:(uint)value {

      uint r = (value & 0x00FF0000) >> 16;

      uint g = (value & 0x0000FF00) >> 8;

      uint b = (value & 0x000000FF);
      return [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:1.0];

}


ps： value = 0xFFFFFF

2.string 类型 #FFFFFF

- (UIColor *) colorWithHexString:(NSString *)stringToConvert
{
    
    NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]uppercaseString];//字符串处理
    
    
    if ([cString length] < 6)
        
        return [UIColor whiteColor];//如果非十六进制，返回白色
    
    if ([cString hasPrefix:@"#"])
        
        cString = [cString substringFromIndex:1];//去掉头
    
    if ([cString length] !=6)//去头非十六进制，返回白色
        
        return [UIColor greenColor];
    
    //分别取RGB的值
    
    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把扫描出的制定的字符串转换成Int类型
    
    [[NSScanner scannerWithString:rString] scanHexInt:&r];
    
    [[NSScanner scannerWithString:gString] scanHexInt:&g];
    
    [[NSScanner scannerWithString:bString] scanHexInt:&b];
    
    //转换为UIColor
    
    return [UIColor colorWithRed:((float) r /255.0f) green:((float) g /255.0f) blue:((float) b /255.0f) alpha:1.0f];
    
}

ps：stringToConvert = #ffffff