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Note

C# 2008 introduces the concept of extension methods. As you will see in Chapter 13, this technique

makes it possible to add new functionality to precompiled types (including sealed types) within your current

project.

Revising Visual Studio Class Diagrams

Back in Chapter 2, I briefly mentioned that Visual Studio 2008 allows you to establish base/derived

class relationships visually at design time. To leverage this aspect of the IDE, your first step is to

include a new class diagram file into your current project. To do so, access the Project ➤ Add New

Item menu option and select the Class Diagram icon (in Figure 6-2, I renamed the file from

ClassDiagram1.cd to Cars.cd).

Figure 6-2.

Inserting a new class diagram

Once you click the Add button, you will be presented with a blank designer surface. To add

types to a class designer, simply drag each file from the Solution Explorer window onto the surface.

When you do so, the IDE responds by automatically including all types on the designer surface.

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Realize that if you delete an item from the visual designer, this will not delete the associated source

code, but simply take it off the designer surface. Our current class hierarchy is shown in Figure 6-3.

Figure 6-3.

The visual designer of Visual Studio