尝试这个:
NSMutableAttributedString* attrString = [[NSMutableAttributedString alloc] initWithString: @"Your String"];
NSUInteger count = 0;
NSUInteger length = [attrString length];
NSRange range = NSMakeRange(0, length);
while(range.location != NSNotFound)
{
range = [[attrString string] rangeOfString:@"YOURWORD" options:0 range:range];
if(range.location != NSNotFound) {
[attrString addAttribute:NSBackgroundColorAttributeName value:YOURCOLOR range:NSMakeRange(range.location, [word length])];
range = NSMakeRange(range.location + range.length, length - (range.location + range.length));
count++;
}
}