如何从抽象类访问继承类的属性

Question

I am working with a code in which there is an abstract class, eg:

public abstract class AbstractClass
{
   ...
}

and there are inherited classes from AbstractClass. One object is created depending on user input from one of inherited classes. Each inherited class has its own properties:

class classOne : AbstractClass
    {
         ...
         public int A { get; set;}
         public int B { get; set;}
         public int C { get; set;}
         ...
    }


class classTwo : AbstractClass
    {
         ...
         public int D { get; set;}
         public int E { get; set;}
         ...
    }

... Say I want to use functions in that code and I know which object type would be returned. How can I modify the properties of the output object since the program is written in a way that the class of output is only determined when the program is run?

Answer 1

If you know what concrete type you'll have, you can always cast your object:

var concreteObject = myObj as classOne;

Or, if you don't know what object type you'll have, you can test for it and then cast:

if (myObj is classOne) {
    // Cast to classOne and use
} else if (myObj is classTwo) {
    // Cast to classTwo and use
}

Hope this helps answer your question!

Answer 2

如果您在运行时知道实例将是特定类型，但您无法向编译器证明它，则可以将其强制转换：

(SomeType)instance