title: Save paragragh formatting on splitting rich text
body: <p>I have a complicated method of rendering RichText using <strong>RichTextBox</strong>.
  If the rich text don't fit on a pages, I use <strong>SelectionStart, SelectionLength</strong> and <strong>SelectedRtf</strong> properties to get part of the rich text.
  But after getting the part of the rich text, some paragraph formatting is lost.
  For example, line spacing.</p>
  
  <p>How to to get part of the rich text with right formatting using standard .Net Framework methods?</p>
  
  <p><strong>I don't need to just copy rich text with formatting.</strong> I need to split rich text if it don't fit in one page. And if there is any paragraph formatting it is lost. Here is a sample where left margin and line spacing is lost.</p>
  
  <p><img src="https://i.stack.imgur.com/HmxDp.jpg" alt="enter image description here"></p>