This print for content only-size & color not accurate 7" X 9-1/4" / casebound / malloy

// Here is our only using directive.

using System;

namespace MyNewApp

{

class JustATest

{

void SomeMethod()

{

// Error! Need to import MyExtensionMethods

// namespace to extend int with Foo()!

int i = 0;

i.Foo();

}

}

}

The IntelliSense of Extension Methods

Given the fact that extension methods are not literally defined on the type being extended, it is cer-

tainly possible to become confused when examining an existing code base. For example, assume

you have imported a namespace that defined some number of extension methods authored by a

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teammate. As you are authoring your code, you might create a variable of the extended type, apply

the dot operator, and find dozens of new methods that are not members of the original class

definition!

Thankfully, Visual Studio’s IntelliSense mechanism marks all extension methods with a unique

“downward arrow” icon (see Figure 13-3), which appears blue on your screen.

Figure 13-3.

The IntelliSense of extension methods

Any method marked with this visual icon is a friendly reminder that the method is defined out-

side of the original class definition via an extension method.