public class clsInvoiceDetail { private int _InvoiceDetailsId; private int _Id; private int _ProductId; private int _Qty; private double _Amount; private double _PaidAmount; private double _TaxAmount; private double _UnitCost = 0; private bool _boolDelete; private string _Description = ""; public int Id { set { _Id = value; } get { return _Id; } } public int InvoiceDetailsid { set { _InvoiceDetailsId = value; } get { return _InvoiceDetailsId; } } public int ProductId { set { if (value == 0) { throw new Exception("Product is compulsory"); } _ProductId = value; } get { return _ProductId; } } public int Quantity { set { if (value < 1) { throw new Exception("Quantity should be numeric"); } _Qty = value; _Amount = _UnitCost * _Qty; } get { return _Qty; } } public double Amount { set { _Amount = value; } get { return _Amount; } } public double PaidAmount { set { _PaidAmount = value; } get { return _PaidAmount; } } public double TaxAmount { set { _TaxAmount = value; } get { return _TaxAmount; } } public double UnitCost { set { if (value == 0) { throw new Exception("Unit cost is compulsory"); } _UnitCost = value; _Amount = _UnitCost * _Qty; } get { return _UnitCost; } } public string ProductDescription { set { _Description = value; } get { return _Description; } } public void Delete() { _boolDelete = true; } public void Update(int _InvoiceReference) { clsInvoiceDB objInvoiceDB = new clsInvoiceDB(); objInvoiceDB.InsertInvoiceDetails(_Id, _InvoiceReference, _ProductId, _Qty,_Amount, _TaxAmount, _PaidAmount, _UnitCost); } } public class clsInvoiceDetails :CollectionBase { public void addInvoiceDetails(clsInvoiceDetail objInvoiceDetail) { List.Add(objInvoiceDetail); } public clsInvoiceDetail getSelectedIndex(int intSelectedIndex) { return (clsInvoiceDetail)List[intSelectedIndex-1]; } } public class clsInvoiceHeader { //we have created invoicedetails object here //one invoice header can have multiple invoice details so we have created the object of invoice details //when we want to depict composition we creat the object inside the parent container private clsInvoiceDetails objInvoiceDetails = new clsInvoiceDetails(); private int intSelectedIndex; private int _InvoiceReference; private string _InvoiceComments=""; private DateTime _InvoiceDate; private double _TaxAmount; private string _CustomerName=""; private string _CustomerAddress=""; public int InvoiceReference { get { return _InvoiceReference; } } public string InvoiceComments { set { _InvoiceComments = value; } get { return _InvoiceComments; } } public DateTime InvoiceDate { set { _InvoiceDate = value; } get { return _InvoiceDate; } } public string CustomerName { set { if (value.Length == 0) { throw new Exception("Customer Name is compulsory"); } _CustomerName = value; } get { return _CustomerName; } } public string CustomerAddress { set { _CustomerAddress = value; } get { return _CustomerAddress; } } public int getSelectedIndex() { return intSelectedIndex; } public void Move(int intIndex) { intSelectedIndex = intIndex; } public void MoveNext() { intSelectedIndex++; } public void MovePrevious() { intSelectedIndex--; } public clsInvoiceDetail getSelectedInvoice() { return objInvoiceDetails.getSelectedIndex(intSelectedIndex); } public clsInvoiceDetail getSelectedInvoice(int _intSelectedIndex) { return objInvoiceDetails.getSelectedIndex(_intSelectedIndex); } public clsInvoiceDetails getInvoiceDetails() { return objInvoiceDetails; } public void addInvoiceDetails() { clsInvoiceDetail objInvoiceDetail = new clsInvoiceDetail(); objInvoiceDetails.addInvoiceDetails(objInvoiceDetail); intSelectedIndex = objInvoiceDetails.Count; } public void Insert() { //if someone calls the insert method of parent it insert into the parent first and then it goes and calls its child to insert //says to its child insert this relation is called as composition clsInvoiceDB objInvoiceDb = new clsInvoiceDB(); _InvoiceReference= objInvoiceDb.InsertInvoiceHeader(_InvoiceReference, _InvoiceComments, _InvoiceDate, _CustomerName, _CustomerAddress); foreach (clsInvoiceDetail obj in objInvoiceDetails) { obj.Update(_InvoiceReference); } } public void Update() { intSelectedIndex = 0; } public void Delete() { } public DataSet getInvoice() { clsInvoiceDB objInvoiceDB = new clsInvoiceDB(); return objInvoiceDB.getInvoice(0); } public void LoadInvoice(int InvoiceNumber) { DataSet objdataset=null; int intRef; clsInvoiceDB objInvoiceDB = new clsInvoiceDB(); objdataset = objInvoiceDB.getInvoice(InvoiceNumber); if(objdataset.Tables[0].Rows.Count!=0) { _CustomerName = objdataset.Tables[0].Rows[0]["Customername"].ToString(); _CustomerAddress = objdataset.Tables[0].Rows[0]["CustomerAddress"].ToString(); _InvoiceReference = Convert.ToInt16(objdataset.Tables[0].Rows[0]["InvoiceNumber"].ToString()); _InvoiceComments = objdataset.Tables[0].Rows[0]["InvoiceComments"].ToString(); _InvoiceDate = Convert.ToDateTime(objdataset.Tables[0].Rows[0]["InvoiceDate"].ToString()); foreach (DataRow objRow in objdataset.Tables[0].Rows) { clsInvoiceDetail objInvDetail = new clsInvoiceDetail(); objInvDetail.Id = Convert.ToInt16(objRow["InvoiceDetailsid"].ToString()); objInvDetail.InvoiceDetailsid = _InvoiceReference; objInvDetail.ProductId = Convert.ToInt16(objRow["Productid_fk"].ToString()); objInvDetail.ProductDescription = objRow["ProductDescription"].ToString(); objInvDetail.Quantity = Convert.ToInt16(objRow["Qty"].ToString()); objInvDetail.Amount = Convert.ToDouble(objRow["Amount"].ToString()); objInvDetail.TaxAmount = Convert.ToDouble(objRow["TaxAmount"].ToString()); objInvDetail.PaidAmount = Convert.ToDouble(objRow["PaidAmount"].ToString()); objInvDetail.UnitCost = Convert.ToDouble(objRow["UnitCost"].ToString()); objInvoiceDetails.addInvoiceDetails(objInvDetail); } } } } public class clsProduct { private int _ProductId; private string _productDescription; private double _UnitCost; public int ProductId { set { _ProductId = value; } get { return _ProductId; } } public string ProductDescription { set { _productDescription = value; } get { return _productDescription; } } public double UnitCost { set { _UnitCost = value; } get { return _UnitCost; } } public DataSet getProducts() { clsInvoiceDB objInvoiceDB = new clsInvoiceDB(); return objInvoiceDB.getProducts(); } }