Once again, the tried and true method in C/C++ is sprintf.
Don't knock it until you've tried it. For example:

 char tempStr[128];
 sprintf_s(tempStr, "%g", value);

  Simple, portable (well, except for the _s part), and has more
possible options than you can shake a stick at.

Nathan Mates
--
<*> Nathan Mates - personal webpage http://www.visi.com/~nathan/ 
# Programmer at Pandemic Studios -- http://www.pandemicstudios.com/
# NOT speaking for Pandemic Studios. "Care not what the neighbors
# think. What are the facts, and to how many decimal places?" -R.A. Heinlein

If you want a C++ way (and not C (like Nathan Mates' solution) or .Net way), you can use stringstream or wstringstream (sprintf is
faster but is not type safe). See interpret_cast in Kevlin Henney's paper (Valued Conversions,
http://www.two-sdg.demon.co.uk/curbralan/papers/ValuedConversions.pdf). Also see lexical_cast (from the same author) in boost
libraries for an updated and more complete version of interpret_cast (http://www.boost.org/libs/conversion/lexical_cast.htm). These
converter templates are very flexible, simple and useful.

Regards

--
Cholo Lennon
Bs.As.
ARG

ToString is a function, not a property.  The () are not optional in C++.
textBox2->Text=F.ToString();