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