? 网上看到的，在这里收藏一下：

? ?互联网 App 中经常会用到 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];
??? }