【转】16进制颜色(html颜色值)字符串转为UIColor

转自：http://www.cocoachina.com/bbs/read.php?tid=63229&page=1 

 

互联应用经常会用到html颜色值转换UIColor，比如：#FF9900,0XFF9900等颜色字符串，以下方法可以将这些字符串转换为 UIColor对象。

 

+ (UIColor *) colorWithHexString: (NSString *) stringToConvert

{

 NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];

 

 // String should be 6 or 8 characters

 if ([cString length] < 6) return DEFAULT_VOID_COLOR;

 

 // strip 0X if it appears

 if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];

 f ([cString hasPrefix:@"#"]) cString = [cString substringFromIndex:1];

 if ([cString length] != 6) return DEFAULT_VOID_COLOR;

 // Separate into r, g, b substrings

 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];

 

 // Scan values

 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];

}