问题
I have an application which involves building rich text character by character in order to undo it all at once. In order to retain that character's formatting, I select it and then can add the SelectedRtf property to my StringBuilder, however I want to be able to build each Rich Text character into one Rich Text string so that I can undo it in one go.
My question is how can you combine Rich Text strings into one big string while retaining all the formatting for each character.
回答1:
merge it this way:
richTextBox2.Select(richTextBox2.TextLength, 0);
richTextBox2.SelectedRtf = richTextBox1.Rtf;
来源：https://stackoverflow.com/questions/4254229/merge-rich-text