Maybe it is a trival question, but it\'s bothering me. And don\'t shout laud if it is a duplicate - I tried to search, but there are so many questions regarding using that i
Once it leaves the using block, Dispose is called.
using Statement (C# Reference)
The using statement calls the Dispose method on the object in the correct way, and (when you use it as shown earlier) it also causes the object itself to go out of scope as soon as Dispose is called. Within the using block, the object is read-only and cannot be modified or reassigned.
The using statement ensures that Dispose is called even if an exception occurs while you are calling methods on the object.