Solved

Shared class - not sure why i get this warning

Posted on 2006-11-13
8
206 Views
Last Modified: 2010-04-23
I have this class:

1.
Namespace Uni.Web.Data.UserData
    Public Class UserAccess

        Private Shared _DBType As DataProvider
        Public Shared Property DBType() As DataProvider
            Get
                Return _DBType
            End Get
            Set(ByVal value As DataProvider)
                _DBType = value

            End Set
        End Property


        Public Shared Function GetSystems(ByVal userLogin As String) As ArrayList
           .....
        End Function

    End Class
End Namespace

2. In my aspx page, why do I need to do this??
 U_DAL.Uni.Web.Data.UserData.UserAccess.DBType =  U_DAL.DataProvider.IBM  

****If I do this, I get a warning:
        Dim test As U_DAL.Uni.Web.Data.UserData.UserAccess
       test.DBType = U_DAL.DataProvider.IBM  

This is the warning : Access of shared member through an instance; qualifying expression will not be evaluated

3. I looked at this site and I'm not using "new" so, that should work:
http://msdn2.microsoft.com/en-us/library/y6t76186.aspx


0
Comment
Question by:Camillia
  • 5
  • 3
8 Comments
 
LVL 6

Expert Comment

by:riyazthad
ID: 17932948
This is better practice to use shared function or property thru instance variable. It is good to use as class member rather than instance member.

So in your case better to use

U_DAL.Uni.Web.Data.UserData.UserAccess.DBType =  U_DAL.DataProvider.IBM

rather than creating a type variable (instance)
0
 
LVL 6

Expert Comment

by:riyazthad
ID: 17932987
"This is NOT better practice to use shared function or property thru instance variable"

sorry for confusion
0
 
LVL 7

Author Comment

by:Camillia
ID: 17933064
but the type variable (instance) should still work..right? or is it changed in 2.0?
0
Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

 
LVL 6

Expert Comment

by:riyazthad
ID: 17933127
Farzadw,

I think this will make more clear.

http://msdn2.microsoft.com/en-US/library/4hbsxy95.aspx

0
 
LVL 7

Author Comment

by:Camillia
ID: 17933288
it says " 
It is recommended that you do not write code in which you access a shared member through an instance of the class
"

but then in the example, it goes and creates an instance of of "item":
' Create two instances of the class.
    Dim part1 As New Item("keyboard")
    Dim part2 As New Item("monitor")

then calls the shared method : Item.ShareMethod()

0
 
LVL 6

Accepted Solution

by:
riyazthad earned 500 total points
ID: 17933404
Yes

But last line Item.SharedMethod , we are calling directly method without creating instance of type 'Item'.

But first two lines part1 and part2 are instances, but we are not calling its shared method, but calling instance method 'InstanceMethod', which is NOT shared method.

Item.ShareMethod()

is just calling its shared method.

So first two calling are recommenting
but not last one becos that is shared method.

in other words

part1.SharedMethod()
or
part2.sharedMethod()

are not recommenting.


0
 
LVL 7

Author Comment

by:Camillia
ID: 17933436
ah, now I get it..

Good, i thought i was doing something wrong...

But the name is too long without creating an instance.
0
 
LVL 6

Expert Comment

by:riyazthad
ID: 17933445
Yea, Its okay though.

:-)

Thad
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
VB.Net WebRequest Code from JSON curl 7 53
How to limit User Input 2 27
VB.NET String Settings and Temp Folder Question 3 55
Data organization issue 7 16
This article explains how to create and use a custom WaterMark textbox class.  The custom WaterMark textbox class allows you to set the WaterMark Background Color and WaterMark text at design time.   IMAGE OF WATERMARKS STEPS Create VB …
Creating an analog clock UserControl seems fairly straight forward.  It is, after all, essentially just a circle with several lines in it!  Two common approaches for rendering an analog clock typically involve either manually calculating points with…
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

827 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question