Question

Here is an example of the code that I’m working with:

    BaseClass class1;
    if (userControl.Key == 100)
    {
        class1 = new DerivedClass1();

        //This does not work, but it seems like it should
        class1.PropertyInDerivedClass1 = 7

        //This does work, but why should I have to cast something that I just instantiated?
        ((DerivedClass1)class1).PropertyInDerivedClass1 = 7;
    }
    else
        class1 = new DerivedClass2();

Is there anything that I can do to be able to more easily access properties and methods within derived classes?

Answer 1

If you wish to use variables of the derived class, you need to address them using a reference with that specific type.

BaseClass obj1; 
DerivedClass dc = new DerivedClass(); 
dc.DerivedPropertyToAccess = value; 
obj1 = dc;

To summarize, the bug in your example code was to access the properties using a reference with the base class type instead of derived class.