I have an application in C# .NET which has a MainForm and a few classes.
One of these classes receives incoming data messages from a network. I need to
You can solve this problem by removing the static keyword.
When you see "static", think: without an instance of this type.
When you call a non-static method, you must explicitly use some instance. The method can access that instance using the "this" keyword.
When you call a static method, there is no instance - you have abandoned the boundaries of OO and are now in a structural or functional programming context. If you want an instance of something, you need to bring it in as a parameter.