using (C# reference)

The using keyword has two major uses:

• The using statement defines a scope at the end of which an object is disposed:

  string filePath = "example.txt";
  string textToWrite = "Hello, this is a test message!";
  
  // Use the using statement to ensure the StreamWriter is properly disposed of
  using (StreamWriter writer = new StreamWriter(filePath))
  {
      writer.WriteLine(textToWrite);
  }
  

• The using directive creates an alias for a namespace or imports types defined in other namespaces:

  using System;
  using System.IO;
  

See also

• C# keywords