How do you create a C# property that can subscribe to another WinForm control at design time?

Question

I want to create a property in a control that will act as a viewer that will be able to connect to another non-visual control to show its current status. In this example let

Answer 1

To have non-UI elements that can be used at design-time in the designer, you can inherit from Component.

using System.ComponentModel;

public interface IHeater
{
    int Temperature { get; set; }
}

public class Heater : Component, IHeater
{
    public int Temperature 
    {
        get;
        set;
    }
}

public class HeaterMonitor:Component
{
    public IHeater Source { get; set; }
}

Then you can use them in design-mode (in component tray):

And select the source this way: