16进制计算颜色
+ (UIColor *)colorFromHexRGB:(NSString *)colorString{
UIColor *resultColor = nil;
unsigned int colorCode = 0;
unsigned char redByte,greenByte,blueByte;
if(nil != colorString){
NSScaner *scanner = [NSScanner scannerWithString:colorString];
(void) [scanner scanHexInt:$colorCode]; // ignore error
}
redByte = (unsigned char) (colorCode >> 16);
greenByte = (unsigned char) (colorCode >> 8);
blueByte = (unsigned char) (colorCode); // masks off high bits
resultColor = [UIColor colorWithRed:(float)redByte/ 0xff
green: (float)greenByte/ 0xff
blue:(float)blueByte/ 0xff
alpha:1.0];
return resultColor;
}