将数据添加到两个共享一对多关系的Class对象

Question

我还不熟悉使用实体框架，我有两个Class对象，Loans和BalanceAndInterest。分别是一对多关系。

我能够设置要存储到Loans对象的对象，但我确定我应该如何将数据添加到BalanceAndInterest并保持其关系。

我以前只需要使用单个类对象，而且我真的知道是谁让这个工作。

类对象：

public class Loan
{
    public Loan() {

        BalanceAndInterest = new List<BalanceAndInterest>();
    }

    public int LoanID { get; set; }
    public string LoanName { get; set; }

    public DateTime LoanDueDate { get; set; }

    public virtual ICollection<BalanceAndInterest> BalanceAndInterest { get; set; }
}


public class BalanceAndInterest
{
    public BalanceAndInterest() { }

    public int BalanceAndInterestId { get; set; }

    public int CurrentBalance { get; set; }
    public int InterestRate { get; set; }

    public virtual Loan Loan { get; set; }
}

我正在尝试加载日期：

loan = new Loan
                {
                    //LoanID
                    LoanName = tbxName.Text,
                    LoanDueDate = Convert.ToDateTime(datePickerFirstDueDate.Text),
                    BalanceAndInterest/// here were I'm getting lost


                };