I see that many people does games in c++ and then úse c# to make tools for the game in there. I mean, making a GUI in c++ takes some time. can anyone agree with this statement or does anyone have any comments on it?
I feel for learning a new language soon and i think the windows API is very boring to use but i feel that i need to learn it. Maybe can c# learn me more about it?
Where did you hear this? Visual Studio 2012 just came out with .Net 4.5 and a bunch of nice improvements in C#, VB, all languages that use the .Net framework. I'm making a "Modern UI" app right now with C# and XAML and it's an absolute pleasure and really easy to get into.
No offense to you guys but my question wasnt really answered
Your question is not answerable. Is it worth me learning Portuguese? Without knowing the environment in which I'm going to need to communicate to people, the question is unanswerable. Is it worth you learning C#? Unasnwerable for much the same reason.
If you want to learn C# in the hopes that you'll absorb knowledge about the Win32 API, why not just explore the Win32 API?
The worth you're going to find in learning the language is going to be based on your goals as far as what you want to make, the people you're going to work with, if you care about being (mostly) tied down to Windows, etc... All things that are different on a case-by-case basis.
Either way, my default answer for "should I learn X" is always yes. I have never heard of a single case where learning a new skill has been detrimental.
You won't learn anything about the Win32 API with C#. When you make GUIs in C#, you generally use Winforms along with the .Net Framework which is completely different than Win32 (and in Windows 8 you'd have to learn the WinRT API). You can use native calls to system dlls and use win32 calls in your code, but the syntax required makes your program look hacky at best.