Change of interface implementation without project recompilation. How to implement?

Question

C++ / C#

Good afternoon. How can you replace the implementation of the functionality in the finished program?
I'll give you an example. I have an interface:

public interface IMessage
    {
        string GetMessage();
    }

There is a class that implements it:

public class Message : IMessage
    {
        public string GetMessage()
        {
            return "Hello From Message Class";
        }
    }

There is a form that creates a class variable and displays the result of the method in a MessageBox:

public partial class Form1 : Form
    {
        private readonly IMessage m;

        public Form1()
        {
            InitializeComponent();
            m = new Message();
        }

        private void Clickbtn_Click(object sender, EventArgs e)
        {
            MessageBox.Show(m.GetMessage());
        }
    }

I'm interested in the following, for example, I have a class that implements the interface will be in a separate dll library.
And I wanted to implement the interface differently. And that I could just create a new dll library and put it in the program folder. Is it possible? It turns out that I need something like creating plugins. What technology can be used to do this?
Thanks in advance for your replies.

Answer 1

Through reflection. Load your assembly, look for classes that implement the interface you need and use them.