?
Solved

What does Strong Typed mean for VB.NET CollectionBase

Posted on 2006-11-24
4
Medium Priority
?
441 Views
Last Modified: 2012-08-13
Hi experts, I'm just wondering what does  Strong Typed mean for .NET CollectionBase Class

is it possible to hold both base and its derived class in a collectionbase?

For example, I have a base class and a class derived from the base class

public class BaseClass
    protected member1 as string

    public overridable sub mySub()
       'do something for base class
    End Sub
End Class

Public Class DerivedClass
   Inherits BaseClass
   
   Public override Sub mySub()
       'Do somthing and override mySub in base class
   End Sub
End Class

Now I define a baseclass collection

Public Class BaseClassCollection
   Inherits CollectionBase
   .....
End Class


and suppose I define an instance of BaseClassCollection

Dim myCollection as BaseClassCollection

and I put a few BaseClass objects and DerivedClass into myCollection. and suppose myCollection.Item(1) is of type DerivedClass

My question is, if I call the member function myCollection.Item(1).mySub(), is baseClass.mySub() invoked or DerivedClass.mySub() invoked?

Thanks for your help


0
Comment
Question by:caibeier
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
4 Comments
 
LVL 9

Accepted Solution

by:
jrscherer earned 2000 total points
ID: 18013350
All depends what type you define for the Item of the BaseClassCollection. If you define it as DerivedClass then the properties of the DerivedClass will be used.
A class inherited from CollectionBase is strong typed. This means only one type can be stored, and you have to define this type through the Item property yourself.

Default Property Item(ByVal index As Integer) As DerivedClass
    Get
        Return CType(InnerList.Item(index), DerivedClass)
    End Get
    Set(ByVal Value As DerivedClass)
        InnerList.Item(index) = Value
    End Set
End Property


Jack.net
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

Microsoft Reports are based on a report definition, which is an XML file that describes data and layout for the report, with a different extension. You can create a client-side report definition language (*.rdlc) file with Visual Studio, and build g…
It was really hard time for me to get the understanding of Delegates in C#. I went through many websites and articles but I found them very clumsy. After going through those sites, I noted down the points in a easy way so here I am sharing that unde…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …
Suggested Courses

762 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