Set WinForms RichTextBox as the source of a PrintDocument

I want to print the contents of a RichTextBox, so I am trying make a PrintDocument out of the RichTextBox. But I dont find a way to convert a simple RichTextBox to a PrintDocument.开发者_运维技巧 Any ideas?

There's quite an extensive article on this on MSDN, Getting WYSIWYG Print Results from a .NET RichTextBox: if that's TLDR then there's a condensed version as a kb article, How to print the content of a RichTextBox control by using Visual C# .NET or Visual C# 2005