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

I've used it a lot in the past to work with input and output streams. You can nest them nicely and it takes away a lot of the potential problems you usually run into (by automatically calling dispose). For example:

        using (FileStream fs = new FileStream("c:\file.txt", FileMode.Open))
        {
            using (BufferedStream bs = new BufferedStream(fs))
            {
                using (System.IO.StreamReader sr = new StreamReader(bs))
                {
                    string output = sr.ReadToEnd();
                }
            }
        }