Question

I want to track TopMost property changes in my custom forms which are referred as (Form). I cannot use override, because TopMost isn’t abstract or virtual, I can’t use new keyword because it has no effect while implicit referring.

What is the best way to deal with such a task? We can substitute any property instead TopMost as long as base class (Form) has neither “change”-event, nor ONSomething virtual method to override, and our property isn’t marked as abstract or virtual.

Example:

I have many classes based on Form

MyForm1:Form, class MyForm2:Form, class MyForm_n:Form

Some “factory” returns instances of Form type

Form f = GetMyForm();

And finally i do

f.TopMost = !f.TopMost;

The deal is that I can’t really use any other return type for Form GetMyForm(). I can’t use interface or other base class except actual Form one (in fact, there is no factory, I use .ParentForm property of some control).

What is the best way to acheive task and keep my code as clean as possible? Thanks in advance.

Answer 1

It sounds like you might want to introduce a new abstract class between your concrete classes and Form. That could have an ObservedTopMost property or something like that, which delegates to TopMost but also raises an event.

It’s important to note that that this will only be useful when the new property is used; it won’t magically spot changes to the existing property from elsewhere. It might be good enough for your purposes though.