Namespaces and Assemblies - Illustrated C# 2005 - page 241

Suppose also that you are writing a program called MyWidgets , and you want to use the
SquareWidget class. The code for the program is in a file called MyWidgets.cs and is shown in
the following example. The code simply creates an object of type SquareWidget and uses the
object's members.

using System;

class WidgetsProgram
{
static void Main( )
{
SquareWidget sq = new SquareWidget(); // From class library.
↑
Not declared in this assembly
sq.SideLength = 5.0; // Set the side length.
Console.WriteLine(sq.Area); // Print out the area.
} ↑
} Not declared in this assembly

Notice that the code doesn't declare class SquareWidget . Instead, you use the class defined
in SuperLib . When you compile the MyWidgets program, however, the compiler must be aware
that your code uses assembly SuperLib so it can get the information about class SquareWidget .
To do this, you need to give the compiler a reference to the assembly, by giving its name and
location.
In Visual Studio, you can add references to a project in the following way:

Select the Solution Explorer and find the References folder underneath the project
name. The References folder contains a list of the assemblies used by the project.

￿

￿Right-c ick the References folder and select Add Reference. There are five tab pages from
which to choose, allowing you to find the class library in different ways.

￿ For our program, select the Browse tab and browse to the DLL file and select it.

￿ Click the OK button, and the reference is added to the project.