What are the uses of “using” in C#?

Question

User kokos answered the wonderful Hidden Features of C# question by mentioning the using keyword. Can you elaborate on that? What are the uses of

Answer 1

using is used when you have a resource that you want disposed after it's been used.

For instance if you allocate a File resource and only need to use it in one section of code for a little reading or writing, using is helpful for disposing of the File resource as soon as your done.

The resource being used needs to implement IDisposable to work properly.

Example:

using (File file = new File (parameters))
{
    *code to do stuff with the file*
}