?
Solved

Need to inherit a class such that variables in the base class are determined in the inherited class

Posted on 2006-06-24
7
Medium Priority
?
176 Views
Last Modified: 2010-04-23
The best way to explain this is with this watered-down example:

public class BaseClass
    public function getEncoded(Arg1 as string, Arg2 as string) as string
          return BCODE + ";" + Arg1 + ";" + Arg2
    end function
end class

public class Class1
     inherits BaseClass
     public const BCODE as string = "AABBCC"
end class


How do I do this?  (the example above gives an error, since BCODE doesn't exist in the base class)
0
Comment
Question by:stev0931
  • 4
  • 2
7 Comments
 

Author Comment

by:stev0931
ID: 16976698
I know that in C++, you can declare something as virtual so that it knows it will be able to find it when the time comes.  Maybe there is an equivelant in VB.NET?
0
 

Author Comment

by:stev0931
ID: 16976730
Another thought: maybe there is a way to do this using interfaces?
0
 
LVL 13

Accepted Solution

by:
iHadi earned 750 total points
ID: 16976838

public class BaseClass
    public function getEncoded(BCODE as string, Arg1 as string, Arg2 as string) as string
          return BCODE + ";" + Arg1 + ";" + Arg2
    end function
end class

public class Class1
     inherits BaseClass
     public const BCODE as string = "AABBCC"
end class
0
Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

 

Author Comment

by:stev0931
ID: 16976849
Thanks!
0
 
LVL 30

Expert Comment

by:Alexandre Simões
ID: 16976869

To avoid having to pass it as a parameter on the function, you could declare an overridable property BCODE on the base class.
Inheriting from it, you just had to override it and set you value.
On you example you use a Constant... you can create a ReadOnly property to simulate that.

Example:

    Public Overridable ReadOnly Property BCODE() As String
        Get
            Return String.Empty
        End Get
    End Property

    Public Function getEncoded(ByVal BCODE As String, ByVal Arg1 As String, ByVal Arg2 As String) As String
        Return BCODE + ";" + Arg1 + ";" + Arg2
    End Function

End Class

Public Class inheritedClass
    Inherits baseClass

    Public Overrides ReadOnly Property BCODE() As String
        Get
            Return "AABBCC"
        End Get
    End Property



Alex :p

0
 
LVL 30

Expert Comment

by:Alexandre Simões
ID: 16976872
Sorry... Copy/Paste error...
I left the BCODE parameter on the getEncoded finction...

This is the correct one:


    Public Overridable ReadOnly Property BCODE() As String
        Get
            Return String.Empty
        End Get
    End Property

    Public Function getEncoded(ByVal Arg1 As String, ByVal Arg2 As String) As String
        Return BCODE + ";" + Arg1 + ";" + Arg2
    End Function

End Class

Public Class inheritedClass
    Inherits baseClass

    Public Overrides ReadOnly Property BCODE() As String
        Get
            Return "AABBCC"
        End Get
    End Property
0
 

Author Comment

by:stev0931
ID: 16976890
Thanks Alex!
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

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

If you're writing a .NET application to connect to an Access .mdb database and use pre-existing queries that require parameters, you've come to the right place! Let's say the pre-existing query(qryCust) in Access takes a Date as a parameter and l…
Parsing a CSV file is a task that we are confronted with regularly, and although there are a vast number of means to do this, as a newbie, the field can be confusing and the tools can seem complex. A simple solution to parsing a customized CSV fi…
Whether it be Exchange Server Crash Issues, Dirty Shutdown Errors or Failed to mount error, Stellar Phoenix Mailbox Exchange Recovery has always got your back. With the help of its easy to understand user interface and 3 simple steps recovery proced…
Enter Foreign and Special Characters Enter characters you can't find on a keyboard using its ASCII code ... and learn how to make a handy reference for yourself using Excel ~ Use these codes in any Windows application! ... whether it is a Micr…

578 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