Design Pattern for deriving multiple classes of com object

William van Aert

Hi Guys,

I am developing an application which uses a com dll.

The com dll provides 2 classes, which inherit from another class.

Class B inherits from A
Class C inherits from A

I'm looking for a design pattern and an example how to implement my problem.
The 2 derives classes are very similar and have the same properties and methods for 95%.

So I would like to create ONE new derived class "E" (for both B and C) in my project which also have the same methods and properties for 95%. I do not want to write all functions twice for each class I inherit.
So I want class E to figure out if its derived from B or C.

What would be the best way to solve this, using maybe a design pattern, and can you please provide a short example.

Thanks, William

6 Replies

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Upendra Pratap Shahi11y ago
Read this and imlement according to this principle.
Pranay Rana11y ago
Dont forget to mark it accepted
William van Aert11y ago
Thank Pranay, I will give it a try.
Pranay Rana11y ago
I dont know how come SOLID Princple is going help here .. because he is reuesting for the pattern not principle.
Pranay Rana11y ago
I suggest you make use of Adapter Design pattern. Adapter Desing pattern is one of GOF patter which used for this purpose only. Adaper Design patter conver incompatible interface in the compatible interface .

for you it will be like

public interface IAdapter
{
returntype PerformAction();
}

public Class Adapter : IAdapter
{
private readonly ThirdpartyDLLClass ClassA;
public Adaper
{
ClassA = new ClassA();
}

public returntype PerformAction()
{
return ClassA .MethodA();
}
}

And make use of this Adapter class.
Upendra Pratap Shahi11y ago
Hello ,

Read below article-

http://www.c-sharpcorner.com/UploadFile/damubetha/solid-principles-in-C-Sharp/