connection with SQL server 2008 r2 in vb class

Put the connection string in your web.config file. Then create a class that contains methods to retrieve the connection string and return it.

web.config:

<configuration>
  <connectionstrings>
    <add name="My_ConnectionString" providername="system.data.providername" connectionstring="Server=servername;Database=databasename;Uid=userid;Pwd=password;" />
  </connectionstrings>
</configuration>

class:

Imports Microsoft.VisualBasic
Imports System.Data
Imports System.IO

Namespace YourNameSpace
    Public Class ConnectionString
 
          Public Function GetConnectionString() As String

    Dim DBConnection As New SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings("My_ConnectionString").ConnectionString)

    Return DBConnection
End Function
  
 
    END Class
END Namespace

This is a very basic solution to give you an idea. You may have to adjust it in order to get what you want.