[2005] Confused on this concept, need help understanding.

[maikeru-sama]

I have a VB.net Class, with a method declared:

Protected Friend Overridable Sub KillThreads

In my windows forms, I can go "Myclass.KillThreads"

Now, I have ASP.Net Class, with a functioned declared:

Protected Friend Shared Function GetUserLoginInfoLogin

In my Web Form, I cannot go "MyClass.GetUserLoginInfoLogin".

I am wondering why I cannot access this method.

[maikeru-sama]

NM, I don't think a Shard Function should be declared as "protected friend". Doing some research, it seems like most put "Shared Function".

However, not sure why protected friend doesn't work.

[rjv_rnjn]

"Protected Friend Shared Function" would work only if the class you are calling it from is derived from the class containing that method. Is that the case and you are still unable to call the method?

[maikeru-sama]

"Protected Friend Shared Function" would work only if the class you are calling it from is derived from the class containing that method. Is that the case and you are still unable to call the method?

Yep, I believe so.

Here is a code snippet:

'class
Public Class Data
 Protected Friend Shared Function GetUserLoginInfoLogin(etc etc) as SQLDatatreader

 End Function
End Class

'web form
SQLDataReader = Data. <-----only Equals and Reference Equals show up

If I make if Public or just Shared Function it works fine. Just trying to understand VB.Net and ASP.Net.

[rjv_rnjn]

If I make if Public or just Shared Function it works fine. Just trying to understand VB.Net and ASP.Net.

In the code snippet you've posted it's not clear whether the "web form" inherits from class "Data" or not. Let's say we have a base class like below:

Public Class MyBasePage
    Inherits System.Web.UI.Page

    Protected Friend Shared Function testFunction() As String
        Return String.Empty
    End Function

End Class

We have another page which derives from this base class.

Partial Class MyInheritedPage
    Inherits MyBasePage
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        MyBasePage.testFunction() ''You'll be able to access the protected shared method here.
    End Sub

End Class

Now let's consider another web page that doesn't inherit from base page

Partial Public Class test
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
MyBasePage. ''Here I do not get the method name.
    End Sub

End Class

I hope I'm able to make the point.

[maikeru-sama]

Data is just a Class that will be used to connect to the database and do CRUD.

The Web Form is just a regular Web Form and does not inherit from Data.

When I am in the Web Form, I want to just access the members without having to instantiate a Data Object, but I don't want anyone outside the assembly to access these methods.

This is all part of me learning OOP, so I am trying to make sure I get the basics down.

[mendhak]

While I'm not going to test this out, it's probably the IDE being confused. If you're using protected friend, you might be able to compile it even if you put the member name there. No guarantees.

[rjv_rnjn]

The Web Form is just a regular Web Form and does not inherit from Data.

Well then you can not access the Protected methods of Data class.

If you're using protected friend, you might be able to compile it even if you put the member name there.

If you're trying to access the protected friend method from a non-derived class, the compiler will give an error.

[maikeru-sama]

Interesting.

Wonder why I can do it in VB.Net?

I wonder if it has to do with it being a shared function?

Regardless, I need to do more research on Visibility.

[maikeru-sama]

Here is what I am talking about.

VB.Net 2.0 Code:

'inside of a class
Public Class Class1
    Protected Friend Sub TestMe()

    End Sub

End Class

'inside of a windows form
Public Class Form1

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim t As New Class1
        t.TestMe() <----intellisense picks this up
    End Sub
End Class

ASP.Net

'class inside of App_Code
Imports Microsoft.VisualBasic
Public Class Data
    Protected Friend Sub TestMe()

    End Sub
End Class

'inside a windows form
Imports System.Data.SqlClient

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 m As New Data
      m.'<---------------Intelisense not picking it up
    End Sub
End Class

In ASP.Net, if I change it to Friend Sub, the compiler says it is private and of course, when it is Protected Friend Sub, the compiler says it is protected.

I just want to get a handle on OOP.

[maikeru-sama]

FYI,

Thanks for restating your question. I created a simple website with a friend method in the app_code like you have. Then I did a publish website to a folder. I checked the bin folder and there are two dlls. One is app_code.dll. The other is ap_web_(some random code).dll. The second one is where the code behind for the aspx pages is stored. This is probably why the friend can't be seen. They are actually part of two separate dlls. In a windows form app, this would all be compiled as one dll.

I hope this helps.

[rjv_rnjn]

My thoughts never raced in that direction. Thanks for sharing this info.