设置RGB颜色的宏

//RGB Color macro
#define UIColorFromRGB(rgbValue) [UIColor \
colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

//RGB color macro with alpha
#define UIColorFromRGBWithAlpha(rgbValue,a) [UIColor \
colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
blue:((float)(rgbValue & 0xFF))/255.0 alpha:a]


//16进制字符串 转换为int
+ (id)colorWithHex:(NSString *)hex alpha:(CGFloat)alpha
{
    NSAssert(7 == hex.length, @"Hex color format error!");
    
    unsigned color = 0;
    NSScanner *hexValueScanner = [NSScanner scannerWithString:[hex substringFromIndex:1]];
    [hexValueScanner scanHexInt:&color];

    int blue = color & 0xFF;
    int green = (color >> 8) & 0xFF;
    int red = (color >> 16) & 0xFF;
        
    return [UIColor colorWithRed:red/255.0 green:green/255.0 blue:blue/255.0 alpha:1.0];
}