我有以下课程：
[Serializable]
public class ClientBLL
{
private int _Rut;
private String _Fullname;
private List<CreditCardBLL> _CreditCards;
public ClientBLL(){}
public int Rut
{
get { return _Rut; }
set { _Rut = value; }
}
public String Fullname
{
get { return _Fullname; }
set { _Fullname = value; }
}
public List<CreditCardBLL> CreditCards
{
get { return _CreditCards; }
set { _CreditCards = value; }
}
public Boolean Create()
{
Boolean exit = false;
try
{
using (DBEntities context = new DBEntities())
{
var clientDAL = context.Client.FirstOrDefault(client
=> client.Rut == Rut);
if (clientDAL == null)
{
clientDAL = new Client();
clientDAL.Rut = Rut;
clientDAL.Fullname = Fullname;
context.Client.AddObject(clientDAL);
exit = context.SaveChanges() > 0;
}
else
{
MessageBox.Show("Client cannot be created! This
Client already exists!");
}
return exit;
}
}
catch (Exception ex)
{
MessageBox.Show("Exception (C, BLL): " + ex.Message);
}
return exit;
}
public void AddCreditCard(CreditCardBLL newCreditCard)
{
newCreditCard.Create(Rut);
CreditCards.Add(newCreditCard);
}
}
[Serializable]
public class CreditCardBLL
{
private int _Number;
private int _Code;
private DateTime _ValidDate;
public CreditCardBLL(){}
public int Number
{
get { return _Number; }
set { _Number = value; }
}
public int Code
{
get { return _Code; }
set { _Code = value; }
}
public DateTime ValidDate
{
get { return _ValidDate; }
set { _ValidDate = value; }
}
public Boolean Create(int ClientRut)
{
Boolean exit = false;
try
{
using (DBEntities context = new DBEntities())
{
var creditCardDAL =
context.CreditCard.FirstOrDefault(card => card.Number
== Number);
if (creditCardDAL == null)
{
creditCardDAL = new CreditCard();
creditCardDAL.Number = Number;
creditCardDAL.Code = Code;
creditCardDAL.ValidDate = ValidDate;
creditCardDAL.Client = ClientRut;
context.CreditCard.AddObject(creditCardDAL);
exit = context.SaveChanges() > 0;
}
else
{
MessageBox.Show("Credit Card cannot be created!
This Credit Card already exists!");
}
return exit;
}
}
catch (Exception ex)
{
MessageBox.Show("Exception (CC, BLL): " + ex.Message);
}
return exit;
}
}
代码隐藏：
Clients.aspx.cs
public partial class Registration : System.Web.UI.Page
{
private List<ClientBLL> clients;
private List<int> pageLoads;
protected void Page_Load(object sender, EventArgs e)
{
int number = Convert.ToInt32(ViewState["Number"]);
number = number + 1;
ViewState["Number"] = number;
MessageBox.Show("Page_Load: " + number);
pageLoads = (List<int>)ViewState["Index"];
if (pageLoads == null)
{
pageLoads = new List<int>();
}
else
{
MessageBox.Show("PageLoads != null");
}
pageLoads.Add(number);
MessageBox.Show("PageLoads.Count: "+pageLoads.Count);
ViewState["Index"] = pageLoads;
for (int i = 0; i < pageLoads.Count; i++)
{
int index = pageLoads.FindIndex(value => value == number);
if (index == 3)
{
FillGridView();
}
MessageBox.Show("Index: " + index);
}
if (!IsPostBack)
{
gvClients.DataSource = new object[] { null };
gvClients.DataBind();
}
else
{
clients = (List<ClientBLL>)ViewState["Clients"];
if (clients == null)
{
clients = new List<ClientBLL>();
}
}
}
protected void gvClients_RowCommand(object sender,
GridViewCommandEventArgs e)
{
if (e.CommandName == "btnAdd")
{
try
{
ClientBLL newClient = new ClientBLL();
String strRut = ((TextBox)gvClients.FooterRow.FindControl("txtRutInsert")).Text;
int intRut = int.Parse(strRut);
newClient.Rut = intRut;
String fullname = ((TextBox)gvClients.FooterRow.FindControl("txtFullnameInsert")).Text;
newClient.Fullname = fullname;
newClient.Create();
clients.Add(newClient);
ViewState["Clients"] = clients;
FillGridView();
}
catch (NullReferenceException ex)
{
MessageBox.Show("NullReferenceException (C, UI): " + ex.Message);
}
catch (FormatException ex)
{
MessageBox.Show("FormatException (C, UI): " + ex.Message);
}
}
else if (e.CommandName == "btnCards")
{
var rowIndex = Convert.ToInt32(e.CommandArgument);
Session["Client"] = clients[rowIndex];
String clientID;
clientID = Session.SessionID;
MessageBox.Show("Client Session ID (Client): " + clientID);
Response.Redirect("CreditCards.aspx");
}
else if (e.CommandName == "btnDelete")
{
}
}
protected Boolean FillGridView()
{
Boolean flag = false;
if (clients == null)
{
MessageBox.Show("Clients is empty! Can't bind to it!");
}
else
{
gvClients.DataSource = clients;
gvClients.DataBind();
flag = true;
}
return flag;
}
}
CreditCards.aspx.cs：
public partial class Cards : System.Web.UI.Page
{
private ClientBLL client;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (Session["Client"] != null)
{
MessageBox.Show("Session Client != null (!IsPostBack)");
}
else
{
MessageBox.Show("Session Client == null (!IsPostBack)");
}
gvCreditCards.DataSource = new object[] { null };
gvCreditCards.DataBind();
}
else
{
client = (ClientBLL)Session["Client"];
//form1 = (HtmlForm) ViewState["Page"];
if (client.CreditCards == null)
{
client.CreditCards = new List<CreditCardBLL>();
}
}
}
protected void gvCreditCards_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "btnAdd")
{
try
{
CreditCardBLL newCreditCard = new CreditCardBLL();
String strNumber = ((TextBox)gvCreditCards.FooterRow.FindControl("txtNumberInsert")).Text;
int intNumber = int.Parse(strNumber);
newCreditCard.Number = intNumber;
String strCode = ((TextBox)gvCreditCards.FooterRow.FindControl("txtCodeInsert")).Text;
int intCode = int.Parse(strCode);
newCreditCard.Code = intCode;
String strValidDate = ((TextBox)gvCreditCards.FooterRow.FindControl("txtValidDateInsert")).Text;
DateTime datValidDate = DateTime.Parse(strValidDate);
newCreditCard.ValidDate = datValidDate;
client.AddCreditCard(newCreditCard);
String clientID;
clientID = Session.SessionID;
MessageBox.Show("Client Session ID (CreditCard): " + clientID);
FillGridView();
}
catch (NullReferenceException ex)
{
MessageBox.Show("NullReferenceException (CC, UI): " + ex.Message);
}
catch (FormatException ex)
{
MessageBox.Show("FormatException (CC, UI): " + ex.Message);
}
}
}
protected Boolean FillGridView()
{
Boolean flag = false;
if (client.CreditCards == null)
{
MessageBox.Show("CreditCards is empty! Can't bind to it!");
}
else
{
gvCreditCards.DataSource = client.CreditCards;
gvCreditCards.DataBind();
flag = true;
}
return flag;
}
protected void btnBackToClients_Click(object sender, EventArgs e)
{
if (Session["Client"] != null)
{
MessageBox.Show("Client's Session != null (Back to Clients)");
}
else
{
MessageBox.Show("Client's Session == null (Back to Clients)");
}
String rut, number;
rut = client.Rut.ToString();
number = client.CreditCards[0].Number.ToString();
MessageBox.Show("Client's rut: " + rut + " CreditCard's number: " + number);
String clientID;
clientID = Session.SessionID;
MessageBox.Show("Client Session ID (CreditCard) after closing the current one: " + clientID);
//Session testing
Boolean testing = true;
Session["Test"] = testing;
Response.Redirect("Clients.aspx");
}
}
嗯，情况是在Clients.aspx.cs中我有一个GridView中的客户端列表，每个客户端都有自己的CreditCards列表。当我点击添加特定客户端的新CreditCards时，它将重定向到CreditCards.aspx.cs，而在添加了whisnk CreditCards之后，它在之前点击的当前客户的CreditCards的GridView中有一个列表。这是棘手的部分。每次我想回到Clients.aspx.cs时，客户端列表（GridView）都消失了，我需要保持活着才能管理客户端。另一方面，需要根据点击的客户端显示CreditCards（GridView）列表。
我已经尝试了很多，但我无法弄清楚!!!
非常感谢!!!