Draw a line inside a UITextView - NSAttributedString

Is it your expected result?

Can you try this:

NSTextTab *listTab = [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentCenter location:self.textView.frame.size.width - tabStyle.firstLineHeadIndent + tabStyle.tailIndent options:@{}];

And this is the full code:

- (void) viewDidAppear:(BOOL)animated {
  [super viewDidAppear:animated];
  NSString *unicodeStr = @"\n\u00a0\t\t\n";
  NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:unicodeStr];
  NSRange strRange = NSMakeRange(0, str.length);

  NSMutableParagraphStyle *const tabStyle = [[NSMutableParagraphStyle alloc] init];
  tabStyle.headIndent = 16; //padding on left and right edges
  tabStyle.firstLineHeadIndent = 16;
  tabStyle.tailIndent = -70;
  NSTextTab *listTab = [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentCenter location:self.textView.frame.size.width - tabStyle.headIndent + tabStyle.tailIndent options:@{}]; //this is how long I want the line to be
  tabStyle.tabStops = @[listTab];
  [str  addAttribute:NSParagraphStyleAttributeName value:tabStyle range:strRange];
  [str addAttribute:NSStrikethroughStyleAttributeName value:[NSNumber numberWithInt:2] range:strRange];

  NSAttributedString *htmlStr = [[NSAttributedString alloc] initWithData:[@"<h1>Lorem ipsum dolor sit er elit lamet</h1>" dataUsingEncoding:NSUnicodeStringEncoding] options:@{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes:nil error:nil];

  [str insertAttributedString:htmlStr atIndex:0];
  [str appendAttributedString:htmlStr];

  self.textView.attributedText = str;
}