Drawing blanks in a textbox

I would like display,开发者_运维知识库 in a textbox, the spaces and the carriage return in order to show the user the exact test formatting, ie using a central point for spaces and an arrow for CRLF. Any idea ?

Eah, it's really hard! But you can replace spaces with some printable symblos for display purposes only. But carriage you shouldn't replace, just add new Symbols.
And before text usage, before writing to file for example, just convert all symbols back to spaces.
This solutiond of course, is not universal and complete.