如何在NSString段落中加粗某些单词

Question

I was wondering if it was possible to bold specific words within a text that is being held in an NSString. I am able to bold, change the font of characters based on their location within the string using NSMutableAttributedString like this:

NSMutableAttributedString *attrString = [[NSMutableAttributedString alloc] initWithString:utf8String];

UIFont *boldFont = [UIFont boldSystemFontOfSize:18];
NSRange boldedRange = NSMakeRange(0, 9);


[attrString beginEditing];

[attrString addAttribute:NSFontAttributeName
                   value:boldFont
                   range:boldedRange];

[attrString endEditing];

But this changes the font of the first 9 characters in the String.

What I want is to put in Bold the following words should they be found within the string: "Questions", "Did you know" and "Further reading". Is this possible? The fact is that I don't know their position in the string.

I did have a look at the question suggesting this is a duplicate, but my question is not exactly the same and the answers provided did not help. I Need to find ranges within a string and then add them to an NSMutableAttributedString, and this is the bit I am asking help for. An answer has been provided that explains how to do that.

EDIT: The supposed duplicate and its answer DO NOT answer the question. This question is more than just finding specific words within a paragraph, it is also about how to format them using NSMutableAttributedString. The answer provided below is the answer. Thanks!

Answer 1

If you don't know substring position then you can use NSRange to find position of substring and using position you can make changes to the substring using NSMutableAttributedString class. example :

UIFont *fontForlabel1 = [UIFont fontWithName:@"Helvetica-Bold" size:14.0];
UIFont *fontForlabel2 = [UIFont fontWithName:@"Helvetica-Bold" size:19.0];
UIFont *fontForlabel3 = [UIFont fontWithName:@"Helvetica" size:12.0];
NSString *text = @"Do you know that or did you know that?";
NSRange range;
UILabel *setlable;
NSMutableAttributedString * attributedString= [[NSMutableAttributedString alloc] initWithString:text];

range = [text rangeOfString:@"Do you know"];
[attributedString addAttributes:@{NSForegroundColorAttributeName: [UIColor whiteColor],NSFontAttributeName:fontForlabel1} range:range];

range = [text rangeOfString:[@"or"];
[attributedString addAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor],NSFontAttributeName:fontForlabel2} range:range];

range = [text rangeOfString:@"did you know that"];
[attributedString addAttributes:@{NSForegroundColorAttributeName: [UIColor whiteColor],NSFontAttributeName:fontForlabel3} range:range];

setlable.attributedText=attributedString;