Introduction
Here is Part 5
Namespace enables us to group logically related classes. We are not required to
provide a class with a namespace. To this point, all the components that we have
created have been members of the global namespace. However, several advantages
result from grouping components into namespaces.
First, namespaces prevent naming collisions. If two companies produce a
component with the same name, then namespaces provide you with a method of
distinguishing the components.
Second, namespaces make it easier to understand the purpose of a class. If we
group all your data access components into a DataAccess namespace and all your
business logic components in a BusinessLogic namespace, then we can immediately
understand the function of a particular class.
In an ASP.NET page, we import a namespace like this:
<%@ Import Namespace="System.Collections" %>
In a Visual Basic component, on the hand, we import a namespace like this:
Imports
System.Collections
We can create your own custom namespaces and group our components into
namespaces by using the Namespace statement. Here is the example given below.
Class1.vb File Code
Imports
Microsoft.VisualBasic
Namespace
AspNetUnleashed.SampleCode
Public Class Namespaced
Public Function
SaySomething() As
String
Return "Something"
End Function
End Class
End Namespace
Default.aspx File Code
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<%@ Import Namespace="System.Collections" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="Label1" runat="server" Text=""></asp:Label>
</div>
</form>
</body>
</html>
Default.aspx.vb File Code
Imports
System.Collections
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal
sender As Object,
ByVal e As
System.EventArgs)
Handles Me.Load
Dim x As New AspNetUnleashed.SampleCode.Namespaced()
Label1.Text = x.SaySomething()
End Sub
End Class
In above example code we use the Namespace statement to group the Namespaced
component into the AspUnleashed.SampleCode namespace. Components in different
files can share the same namespace, and different components in the same file
can occupy different namespaces.
Note: Continue in Next Part.
HAVE A GREAT CODING!