Call the method in the constructor after the initialization

Question

The CalcTradePrice method should be called right after Trade object's initialization. Right now, it is being called before that, which leads to an exception:

System.DivideByZeroException: 'Attempted to divide by zero.'

var trade = new Trade
{
    Pair = pair,
    OpenRate = buyCandle.Close,
    OpenDate = buyCandle.OpenTime,
    Amount = 12345,
    OpenFee = _backtestOptions.OpenFee,
    CloseFee = _backtestOptions.CloseFee,
    IsOpen = true
};

I know I can manually call the method after the initialization, just like that:

var trade = new Trade
{
    Pair = pair
};
CalcTradePrice();

or to create a derived class which executes it, but I don't want to. Any recommendations?

The Trade class:

public class Trade
{
    public string Pair { get; set; }
    public decimal OpenRate { get; set; }
    public decimal CloseRate { get; set; }
    public DateTime OpenDate { get; set; }
    public DateTime CloseDate { get; set; }
    public decimal OpenTradePrice { get; set; }
    public decimal Amount { get; set; }
    public decimal OpenFee { get; set; }
    public decimal CloseFee { get; set; }
    public SellType SellType { get; set; }
    
    public Trade()
    {
        CalcTradePrice();
    }
    
    public void CalcTradePrice()
    {
        this.OpenTradePrice = ... // DivideByZeroException because all elements are null at that moment
    }
}

Answer 1

You can create parameterized constructor. Assign all properties through parameters passed to constructor.Use these properties to calculate trade price in CalcTradePrice() function.

public class Trade
{
    ...
    
    //I just passed two properties as an example, you can pass all required properties.
    public Trade(int currentBalance, int candleCloseValue)
    {
        this.CurrentBalance = currentBalance;
        this.CandleCloseValue= candleCloseValue;
        CalcTradePrice();
    }
    
    public void CalcTradePrice()
    {
        this.OpenTradePrice = this.CurrentBalance/this.CandleCloseValue; 
    }
}

While creating object of Trade class, pass values as a parameter like,

var currentBalance = 100;
var candleCloseValue = 20;  
Trade trade = new Trade(currentBalance , candleCloseValue);

Note: I used above two properties just to show, how you can assign property values before calling CalcTradePrice() function.

Answer 2

What about this:

public class Trade
{
    public string Pair { get; set; }
    public decimal OpenRate { get; set; }
    public decimal CloseRate { get; set; }
    public DateTime OpenDate { get; set; }
    public DateTime CloseDate { get; set; }
    public decimal OpenTradePrice { get; set; }
    public decimal Amount { get; set; }
    public decimal OpenFee { get; set; }
    public decimal CloseFee { get; set; }
    public SellType SellType { get; set; }
    
    public Trade(buyCandle,_backtestOptions, ..and so on )
    {

    Pair = pair,
    OpenRate = buyCandle.Close;
    OpenDate = buyCandle.OpenTime;
    Amount = currentBalance / buyCandle.Close;
    OpenFee = _backtestOptions.OpenFee;
    CloseFee = _backtestOptions.CloseFee;
    IsOpen = true;

     CalcTradePrice();

     }
};

Answer 3

Your exception System.DivideByZeroException: 'Attempted to divide by zero.' may be triggered by

Amount = currentBalance / buyCandle.Close

rather than your constructor call.