The System.Windows.Forms Namespace

You’ve already seen how namespaces are used to organize related classes in the .NET Framework. The main namespace used for Windows Forms classes is System.Windows.Forms. The classes in this namespace are contained in the System.Windows.Forms.dll assembly.

If you choose a Windows application project or Windows Control Library project in VS.NET, a reference to System.Windows.Forms.dll is added by default. In some other cases, such as creating a library that will work with controls, you need to add that reference manually. (You can see more about creating controls in Windows Forms in Chapter 16.)