Question

I have classes that described below. Does GC collect field1 and field2 from object “a” in class “C” ?

public abstract class A
{
//some methods and properties
}

public class B : A
{
 public int field1 { get; set; }
 public int field2 { get; set; }
}

public class C
{
 public A a { get; set; }
 private System.Windows.Forms.Timer timer;
 public C()
 {
    a = (A)typeof(B).GetConstructor(bla, bla, bla).Invoke(bla, bla);
    ((B)a).field1 = 25;
    timer = new System.Windows.Forms.Timer();
    timer.Enabled = true;
    timer.Interval = 10000;
    timer.OnTick += (o, e) => { Console.WriteLine(((B)a).field1); }; 
 }
}

Answer 1

As long as a is in scope, field1 and field2 will remain in scope. As long as the Timer continues to run and reference a, or a reference to your instance of C exists, a will remain in scope.

I think what you’re asking is if they’ll be lost because we only statically know of the instance of A as an instance of A, not as an instance of B. The answer to that is no, the info remains in scope.