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Creating Your own Namespace...

P: n/a
Something thats been bugging me for a while...

how do you create a namespace that has many children (namespaces)

I.e system.io.blah.blah

Iv'e done it by creating a class which contains another class.

i can see the properties of the first class and the namespace of the second
(inner class) but can't see the properties of the 2nd....

This might not have been put very well............
Nov 20 '05 #1
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8 Replies


P: n/a
Thus spake Simon Edwards:
how do you create a namespace that has many children (namespaces)


Just specify the desired namespace in each file:

(File A)
namespace MyUtilityLibrary.Data

(File B)
namespace MyUtilityLibrary.Data.Sql

--
There are 10 kinds of people. Those who understand binary and those who
don't.

http://code.acadx.com
Nov 20 '05 #2

P: n/a
Ok i've put something together as an example...

Public Class Test1

Public ReadOnly Property test1_prop()

Get

End Get

End Property

Public Class Test2

Public ReadOnly Property test2_prop()

Get

End Get

End Property

End Class

End Class

The above when insntaned will let you see the test1 property and the test 2
class but not thye test2 property?

i want to build my own classes with a structure similar to how dot net works
with its namespaces

fr****@acadx.com> wrote in message
news:eI**************@TK2MSFTNGP10.phx.gbl...
Thus spake Simon Edwards:
how do you create a namespace that has many children (namespaces)


Just specify the desired namespace in each file:

(File A)
namespace MyUtilityLibrary.Data

(File B)
namespace MyUtilityLibrary.Data.Sql

--
There are 10 kinds of people. Those who understand binary and those who
don't.

http://code.acadx.com

Nov 20 '05 #3

P: n/a
Hello,

"Simon Edwards" <si************@hotmail.com> schrieb:
how do you create a namespace that has many children
(namespaces)

I.e system.io.blah.blah

Iv'e done it by creating a class which contains another class.

i can see the properties of the first class and the namespace of the second (inner class) but can't see the properties of the 2nd....

This might not have been put very well............


\\\
Namespace Bla
Namespace Foo
...
End Namespace

Namespace Gac
...
End Namespace
End Namespace

Namespace Moo
...
End Namespace

Namespace Moo.Baz
...
End Namespace

Namespace Moo.Goo
...
End Namespace
///

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
http://www.mvps.org/dotnet
Nov 20 '05 #4

P: n/a
Thus spake Simon Edwards:
i want to build my own classes with a structure similar to how dot
net works with its namespaces


Your example shows nested classes, not namespaces. Typically, a nested
class is meant for use only within its parent class. Namespaces are
simply organizational units.

Let's say you have a console application project with three files. The
first one we'll leave alone. In the second one, change the namespace to
MyConsoleApp.Blah. in the third one, change the namespace to
MyConsoleApp.Blah.Blah.

Now go back to the first file and add a pair of using directives:

using MyConsoleApp.Blah;
using MyConsoleApp.Blah.Blah.

See how the IntelliSense pops out? Now that you have multiple
namespaces, you can use them to organize your classes as you see fit.

--
There are 10 kinds of people. Those who understand binary and those who
don't.

http://code.acadx.com
Nov 20 '05 #5

P: n/a
Hello,

"Simon Edwards" <si************@hotmail.com> schrieb:
Ok i've put something together as an example...

Public Class Test1

Public ReadOnly Property test1_prop()

Get

End Get

End Property

Public Class Test2

Public ReadOnly Property test2_prop()

Get

End Get

End Property

End Class

End Class

The above when insntaned will let you see the test1
property and the test 2 class but not thye test2 property?

i want to build my own classes with a structure similar to
how dot net works with its namespaces


Classes are different from namespaces. Are you sure you understand the
difference between them? If you don't understand it, I would suggest to
have a quick look at the VB.NET documentation. Your sample shows a
declaration of a class inside a class, this has nothing to do with
namespaces.

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
http://www.mvps.org/dotnet
Nov 20 '05 #6

P: n/a
Hi Simon,

Namespaces are for differentiating between classes (and other entities)
which have the same name.

Consider:
Namespace Edwards
Class Simon
End Class
End Namespace

Namespace Jones
Class Simon
End Class
End Namespace

Now, somewhere else, I want to create an instance of a Simon.
Dim MyMan As Simon

This will fail, however, - the compiler complaining that there is a choice
of two.

I have to qualify it with the appropriate namespace.
Dim MyMan As Edwards.Simon

This will work and that, simplified, is what namespaces are for.

===============================
Nested classes are for when you need the facilities that a class provides
but only for the exclusive use of the outer class. This is not as common a
situation as you seem to be implying. Usually the inner class will be Private
or Protected. If it is going to be Public, there's little point in having it
nested.

Public Class clsOuter
Public OuterField As New clsInner
Public Class clsInner
Public InnerField As Integer = 3
End Class
End Class

Somewhere you declare an instance of the outer class:
Dim oFoo As clsOuter

This will create an instance of clsInner for itself and that will set its
InnerField to 3.

With oFoo you can access OuterField but not InnerField.
With oFoo.OuterField you can access InnerField.

===============================
Usually you have the inner class as Private and expose it indirectly using
Properties.

Public Class clsOuter
Private MyInner As New clsInner
Public ReadOnly Property OuterProp As Integer
Get
Return MyInner.InnerField
End Get
End Property
Private Class clsInner
Public InnerField As Integer = 3
End Class
End Class

Somewhere you declare an instance of the outer class:
Dim oFoo As clsOuter

This will again create an instance of clsInner for itself whiich will set
its InnerField to 3.

With oFoo you can only access OuterProp which will give you InnerField's
value.

===============================
I'm intrigued - can you tell us more about this hierarchy that you want to
build ?

Regards,
Fergus
Nov 20 '05 #7

P: n/a
I am only using C#, but I assume this works the same way in VB.NET; The
answer applies to projects in visual studio.net.

You may change the default namespace of your project by using the properties
on the project; right-click the project-name, select "properties", find
"default namespace". Here you may want to change from the "project-name"
(which is the normal) to "company.project" or something.

Further, by creating subdirectories in the project folder, the namespace for
new elements will default to the default namespace-name of elements in the
parent directory + the name of the directory.

You may also change the namespace manually using the namespace-statement;
this is what automatically happens using the methods mentioned above.

What I think would be normal with regards to namespace; would be to make
library-projects with sensible namespaces for what library it is;
company.controls.winforms company.net.smtp; and such; and in the main
program just use the default namespace. You may want to subdivide some
libraries, then you would use folders to create new namespaces.

Regards,

Harald Bjorøy
www.ulriken-consulting.no
"Simon Edwards" <si************@hotmail.com> wrote in message
news:10***************@ananke.eclipse.net.uk...
Ok i've put something together as an example...

Public Class Test1

Public ReadOnly Property test1_prop()

Get

End Get

End Property

Public Class Test2

Public ReadOnly Property test2_prop()

Get

End Get

End Property

End Class

End Class

The above when insntaned will let you see the test1 property and the test 2 class but not thye test2 property?

i want to build my own classes with a structure similar to how dot net works with its namespaces

fr****@acadx.com> wrote in message
news:eI**************@TK2MSFTNGP10.phx.gbl...
Thus spake Simon Edwards:
how do you create a namespace that has many children (namespaces)


Just specify the desired namespace in each file:

(File A)
namespace MyUtilityLibrary.Data

(File B)
namespace MyUtilityLibrary.Data.Sql

--
There are 10 kinds of people. Those who understand binary and those who
don't.

http://code.acadx.com


Nov 20 '05 #8

P: n/a
Quick overview: Namespaces are used to organize and differentiate classes,
structures and other types. Declaring nested classes will allow you to
organize your classes, but you'll have troubles when you need to create
instances of the classes. Namespaces have little overhead and are more
purely for organizational purposes.

Check out the documentation at:
http://msdn.microsoft.com/library/de...us/vblr7/html/
vastmNamespace.asp
The frameworks classes are organized using namespace statements like the
following:

Namespace System

Namespace IO
Class Steam
End Class

Class File
End Class
End Namespace

Namespace Data
Class Connection
End Class
End Namespace
End Namespace

However, the Namespace statement in VB has a trick that will save you a
lot of typing: you can declare multiple nested namespaces in one Namespace
statement by using the "." to separate nested namespaces.

The following declaration declares three namespaces, System, IO, and
Stream, one nested within the other

NameSpace System.IO.Stream
Class Test
End Class
End Namespace

This is equivalent to

Namespace System
Namespace IO
Namespace Stream
Class Test
End Class
End Namespace
End Namespace
End Namespace
--------------------
From: "Simon Edwards" <si************@hotmail.com>
Subject: Creating Your own Namespace...
Date: Fri, 19 Sep 2003 22:59:11 +0100
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Something thats been bugging me for a while...

how do you create a namespace that has many children (namespaces)

I.e system.io.blah.blah

Iv'e done it by creating a class which contains another class.

i can see the properties of the first class and the namespace of the second
(inner class) but can't see the properties of the 2nd....

This might not have been put very well............


Nov 20 '05 #9

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