درک تخلفات جامد در یک کلاس (با مثال و راه حل)

public class Account
{
    public decimal balance { get; set; }
    public decimal CalculateInterest(string accountType)
    {
        decimal interest = 0;
        if (accountType.Equals("Regular"))
        {
            interest = balance * 0.4m;
            if (balance < 1000)
                interest -= balance * 0.2m;
            else if (balance < 50000)
                interest += balance * 0.4m;
        }
        else if (accountType.Equals("Salary"))
        {
            interest = balance * 0.5m;
        }
        return interest;
    }
}

public abstract class Account
{
    public decimal Balance { get; set; }
    public abstract decimal CalculateInterest();
}

public class RegularAccount : Account
{
    public override decimal CalculateInterest()
    {
        decimal interest = Balance * 0.4m;
        if (Balance < 1000)
            interest -= Balance * 0.2m;
        else if (Balance < 50000)
            interest += Balance * 0.4m;
        return interest;
    }
}

public class SalaryAccount : Account
{
    public override decimal CalculateInterest()
    {
        return Balance * 0.5m;
    }
}

public interface IInterestCalculator
{
    decimal CalculateInterest(decimal balance);
}

public class RegularAccountInterestCalculator : IInterestCalculator
{
    public decimal CalculateInterest(decimal balance)
    {
        decimal interest = balance * 0.4m;
        if (balance < 1000)
            interest -= balance * 0.2m;
        else if (balance < 50000)
            interest += balance * 0.4m;
        return interest;
    }
}

public class SalaryAccountInterestCalculator : IInterestCalculator
{
    public decimal CalculateInterest(decimal balance)
    {
        return balance * 0.5m;
    }
}

public class Account
{
    public decimal Balance { get; set; }
    private readonly IInterestCalculator _interestCalculator;

    public Account(IInterestCalculator interestCalculator)
    {
        _interestCalculator = interestCalculator;
    }

    public decimal CalculateInterest()
    {
        return _interestCalculator.CalculateInterest(Balance);
    }
}