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