>>>>>E.g. I have middlewarebase class that has protected virtual property. I have middlewareMain class that has Invoke method and the two methods to set and return invokestring. I also have Sales class with the exact same methods of setting and getting that string.
>>>>>
>>>>>I set the invokestring in the MiddlewareMain and I need to read it in Sales class.
>>>>
>>>>Of course - if you set an instance property of classX, don't expect that this will change an instance property of classY
>>>
>>>But this is what I need. I need to set the string in one class and read it in the other class.
>>
>>Then I misunderstood what you want to do and Bonnie is right - a static property is the only way.
>
>I now have another question. Say, I have
>

>Application 
>{
>
>  Database Database {get;set}
>
>   public Application(Database database)
>   {
>       Database = database;
>   }
>}
>

>
>How can I from the database class set properties of the Application class (its parent in VFP terminology)?

You can't. The Application class is NOT it's parent - it's just holding a reference to it. Countless other classes might also hold a reference to the same object.