Solved

Interface Method 1 to keep and 1 to override...

Posted on 2011-09-22
3
185 Views
Last Modified: 2012-06-21
Hello, I have a data connection wrapper I'm building to allow programs to act as the data source for another.

Here is the issue.  I have an interface, "IDataEngine", and in it, it has 2 methods.  (more, but it only needs 2 for this example of it)  
The Methods are,

public DataSet QuerySet(string sql); // inheriting classes should need to override this;

public DataTable QueryTable(string sql) // inheriting classes should not need to override this.
{
  // does error checking but is essentially,
  return QuerySet(sql).Tables[0];
}

Clearly, I do not need EVERY inheriting app to rewrite the same code for QueryTable, since it will be the same EVERY time.  

But so far, every time I tell a class to implement the IDataEngine interface, it overrides the methods that have code as well as the ones without.

How do I change this, so overriding classes do not need to rewrite methods that are already functional on an interface?  Thanks.
0
Comment
Question by:hpdvs2
  • 2
3 Comments
 
LVL 8

Author Comment

by:hpdvs2
ID: 36582956
I just resolved it one way, but using an abstract class, and marking only the few methods, like QuerySet to abstract as well.

Despite that, I'm sure I've seen this done with an interface, but its dificult finding this kind of information by searching.

Anyone know if this can be done with an interface?  (without producing static methods that the overiding methods can call?)
0
 
LVL 4

Accepted Solution

by:
theHollow earned 500 total points
ID: 36583311
Hello
Interfaces cannot hold code. I don't think that you have seen this anywhere :-)
So what you need to do, is what it seens that you have already done.

You have to make base class for this, instead of an interface.
 - The class itself should be marked with "abstract".
 - The method that should be overridden (QuerySet) should be marked as "abstract" as well, and hold no code
 - The method that should not be overridden (QueryTable) should not be marked with "abstract"

The abstract methods and properties will be generating a build error if not implemented when you inherit from the base class.

None of these methods needs to be marked as "static" unless you want them to be available from the class itelf without being instanced.

Hope that clearified a bit :-)
0
 
LVL 8

Author Comment

by:hpdvs2
ID: 36599746
And I'm also finding validation on this as well.  
0

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
how to read json value 2 49
Why does my excel data start at B1 instead of A1. 9 83
PrintingFoundIt(Almost!(Damn!)) 1 27
VB.NET 2008 Winforms Signing 13 19
Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
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…
Established in 1997, Technology Architects has become one of the most reputable technology solutions companies in the country. TA have been providing businesses with cost effective state-of-the-art solutions and unparalleled service that is designed…
Email security requires an ever evolving service that stays up to date with counter-evolving threats. The Email Laundry perform Research and Development to ensure their email security service evolves faster than cyber criminals. We apply our Threat…

773 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