C#

public abstract class Indicator : ExtendedIndicator
{
    [global::Newtonsoft.Json.JsonIgnoreAttribute]
    protected ITradingManager? TradingManager { get; }
}

class MyTradingManager
{
      public ITradingManager _tradeManager;


      public MyTradeManager(ITradingManager argTradingManager)
      {
       _tradeManager = argTradingManager;
      }

}

internal class SampleIndicator : Indicator
{
      MyTradeManager _tradingManager;

      public SampleIndicator ()
      {
           _tradingManager = new(TradingManager ); <- Here the problem occurs !!!
      }
}

public class Student  
{  
        int id = 1234;
        String name = "gustav";
        bool state = true;
}  

public override bool ProcessKeyDown(KeyEventArgs e)
{
    if (e.IsRepeat) return false;
    if (e.Key == Key.Escape)
    {
          //do sth
    }
}

KeyEventArgs e

public class Person : INotifyPropertyChanged
{
    private string name;

    public event PropertyChangedEventHandler PropertyChanged;

    public string Name
    {
        get { return name; }
        set
        {
            object before = Name;
            name = value;
            OnPropertyChanged("Name", before, Name);
        }
    }

    void OnPropertyChanged(PropertyChangedEventArgs e, object? argvaluebefore = null, object? argnewvalue = null, [CallerMemberName] string argcallername = "", [CallerLineNumber] int argcallerline = 0)
	{
        //How can I inject argvaluebefore and argvalue here ?
		
		PropertyChanged?.Invoke(this, e);
	}
}



public class Master
{

	Person _person = new();


	public Master()
	{
	
		_person.PropertyChanged += MyHandler;
	
	
	}
	

	private void MyHandler(object? sender, PropertyChangedEventArgs e)
	{

		//How do I retrieve the curent values of property Name here plus the value before ?

	}


}

using System;
using System.IO.Ports;

class PortDataReceived
{
    public static void Main()
    {
        SerialPort mySerialPort = new SerialPort("COM3");

        mySerialPort.BaudRate = 56000;
        mySerialPort.Parity = Parity.None;
        mySerialPort.StopBits = StopBits.One;
        mySerialPort.DataBits = 8;
        mySerialPort.Handshake = Handshake.None;
        mySerialPort.RtsEnable = true;

        mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);

        mySerialPort.Open();

        Console.WriteLine("Press any key to continue...");
        Console.WriteLine();
        Console.ReadKey();
        mySerialPort.Close();
    }

    private static void DataReceivedHandler(
                        object sender,
                        SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;
        string indata = sp.ReadExisting();
        Console.WriteLine("Data Received:" );
        Console.Write(indata);
    }
}