How do you use NSAttributedString?

Question

Multiple colours in an NSString or NSMutableStrings are not possible. So I\'ve heard a little about the NSAttributedString which was introduced wit

Answer 1

When building attributed strings, I prefer to use the mutable subclass, just to keep things cleaner.

That being said, here's how you create a tri-color attributed string:

NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:@"firstsecondthird"];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)];

_{typed in a browser. caveat implementor}

Obviously you're not going to hard-code in the ranges like this. Perhaps instead you could do something like:

NSDictionary * wordToColorMapping = ....;  //an NSDictionary of NSString => UIColor pairs
NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:@""];
for (NSString * word in wordToColorMapping) {
  UIColor * color = [wordToColorMapping objectForKey:word];
  NSDictionary * attributes = [NSDictionary dictionaryWithObject:color forKey:NSForegroundColorAttributeName];
  NSAttributedString * subString = [[NSAttributedString alloc] initWithString:word attributes:attributes];
  [string appendAttributedString:subString];
  [subString release];
}

//display string