Question

Is there a way to initialize constant values in c# at runtime like with initialization lists in c++-ctors?

Specifically, I want to make sure that a specific value (the port used) is not changed after the main class was created. Maybe there’s another way to do this.

Answer 1

You can use the readonly keyword:

When a field declaration includes a readonly modifier, assignments to
the fields introduced by the declaration can only occur as part of the
declaration or in a constructor in the same class.

Example (copied from the linked MSDN page):

class Age
{
    readonly int _year;
    Age(int year)
    {
        _year = year;
    }
    void ChangeYear()
    {
        //_year = 1967; // Compile error if uncommented.
    }
}