C# & VB.NET Conversion Pocket Reference

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C# & VB.NET Conversion Pocket Reference

Whenever you compile a .NET project, the IDE automati-

cally generates one of these LIBIDs, so even if you do not

have this attribute in your project, your type library will have

a LIBID. However, unless you set this attribute explicitly,

every time you compile you run the risk of the compiler gen-

erating a new number. Having a new GUID every time you

recompile is not desirable. The GUID itself is generated using

an algorithm that takes into consideration the name of the

assembly and the names of all the public classes and inter-

faces, as well as the project’s version number. Project GUIDs

are not guaranteed to be unique. If two people in two differ-

ent machines generate the same types of projects with the

same names for each class and interface, and assign the same

version number, they will both end up with the same LIBID.

Adding this attribute means that you are taking full control

of when that GUID gets changed.

The

AssemblyDelaySign, AssemblyKeyFile, and

AssemblyKeyName attributes (added to C# projects) have to do

with digitally signing your assembly. Before adding an assem-

bly to the global assembly cache (which contains assemblies

that are shared among multiple projects), the assembly must

be digitally signed. These attributes influence how the assem-

bly is signed. Typically, these attributes should be added to

projects whose resulting DLL will be added to the GAC. If

you need to digitally sign an assembly, you must add these

attributes to your source code (in VB by hand). An alterna-

tive to adding these attributes to your code is to compile your

program with the command-line compiler and use the /delay-

sign, /keyfile, and /keycontainer switches.

Default/Root Namespace

A namespace is a prefix that is added to each class name in

order to make the name of the class unique. Many times,

companies use the company name plus the project name as a

namespace name.

IDE Differences

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Both VB.NET and C# enable you to specify a default

namespace through a project setting. To get to this setting in

VB.NET, first locate the Solution Explorer window, right-

click on the project name, and choose Properties from the

popup menu. A dialog appears with project settings; under

Common Properties

➝ General, you will see a field called

Root namespace. Follow the same steps in C#, but the field

in the Common Properties

➝ General dialog is called Default

namespace.

In C#, having a default namespace means that any time you

ask the IDE to add a new class file to your project, the wiz-

ard creates a file that declares the default namespace, then

adds the new class definition within the namespace. For

example, if your default namespace is WidgetsUSA, when

you choose Project

➝ Add Class from the menu, the wizard

creates a source file that looks like the following:

namespace WidgetsUSA

{

public class Class2

{

}

}

If you change the default namespace setting, then any new

files you generate will have the new namespace name; old

files retain the previous namespace name. You could also set

this property to blank, and then the wizard would not add a

namespace declaration.

In VB.NET, when you assign a root namespace to your

project, all classes in the project automatically become part

of the root namespace. The wizard does not add a

namespace definition to the source files; the setting takes

effect at compile time. If you add a namespace declaration to

the source explicitly, the compiler still appends the root

namespace to the name of each class. If you set the root

namespace to WidgetsUSA and write code that defines a

Banking namespace with a class called Account, as follows:

C#