How to set a different font size just for UITextView's first line of?

Question

I got a UItextView, I want the first line of its content to have larger size than the rest.
Like the following image.
Example
But I don't see any font size related attribute in paragraph attributes.
So, how to do that?
Thanks for any advices.

@MahendraGP But the UITextView is dynamic. The content is allowed editing. — Nouvea, Feb 13 '19 at 11:32
@MahendraGP Dynamically Change the attributes in the delegate method doesn't feel like a good method. — Nouvea, Feb 13 '19 at 11:33
Possible duplicate of [Example of NSAttributedString with two different font sizes?](https://stackoverflow.com/questions/18365631/example-of-nsattributedstring-with-two-different-font-sizes) — Naresh, Feb 13 '19 at 11:59

score 0 · Answer 1 · answered Feb 13 '19 at 11:43

Use NSMutableAttributedString..

            NSMutableAttributedString *firstLine = [[NSMutableAttributedString alloc]initWithString:@"First Line\n" attributes:@{NSFontAttributeName : [UIFont boldSystemFontOfSize:20]}];

            NSAttributedString *secondLine = [[NSAttributedString alloc]initWithString:@"Second Line" attributes:@{NSFontAttributeName : [UIFont systemFontOfSize:16]}];

            [firstLine appendAttributedString:secondLine];
            yourTextView.attributedText = firstLine;

score 0 · Answer 2 · answered Feb 13 '19 at 11:50

Have you tried attributed String? You just need to know how long your first line will be.

// 16.0 is your standard font size for the textView
let text = NSMutableAttributedString(string: "your whole text for the textview", attributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 16.0)])
// 23.0 is the size for your first line
text.addAttribute(NSAttributedStringKey.font, value: UIFont.systemFont(ofSize: 23.0), range: NSRange(location: 0, length: firstLineLength))

textView.attributedText = text