Salve,
sto cercando di imparare asp.net, e sto analizzando uno starterkit, qualcuno può darmi una indicazione su questo messaggio di errore?

Messaggio di errore del parser: La classe base contiene il campo 'Email', il cui tipo (System.String) non è compatibile con quello del controllo (System.Web.UI.WebControls.TextBox).

Di seguito il codice. Grazie



using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

namespace ASPNET.StarterKit.Commerce {

//************************************************** *****
//
// CustomerDetails Class
//
// A simple data class that encapsulates details about
// a particular customer inside the Commerce Customer
// database.
//
//************************************************** *****

public class CustomerDetails : System.Web.UI.Page
{

public String FullName;
public String Email;
public String Password;
}

//************************************************** *****
//
// CustomersDB Class
//
// Business/Data Logic Class that encapsulates all data
// logic necessary to add/login/query customers within
// the Commerce Customer database.
//
//************************************************** *****

public class CustomersDB {

//************************************************** *****
//
// CustomersDB.GetCustomerDetails() Method <a name="GetCustomerDetails"></a>
//
// The GetCustomerDetails method returns a CustomerDetails
// struct that contains information about a specific
// customer (name, email, password, etc).
//
// Other relevant sources:
// + CustomerDetail Stored Procedure
//
//************************************************** *****

public CustomerDetails GetCustomerDetails(String customerID)
{

// Create Instance of Connection and Command Object
SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
SqlCommand myCommand = new SqlCommand("CMRC_CustomerDetail", myConnection);

// Mark the Command as a SPROC
myCommand.CommandType = CommandType.StoredProcedure;

// Add Parameters to SPROC
SqlParameter parameterCustomerID = new SqlParameter("@CustomerID", SqlDbType.Int, 4);
parameterCustomerID.Value = Int32.Parse(customerID);
myCommand.Parameters.Add(parameterCustomerID);

SqlParameter parameterFullName = new SqlParameter("@FullName", SqlDbType.NVarChar, 50);
parameterFullName.Direction = ParameterDirection.Output;
myCommand.Parameters.Add(parameterFullName);

SqlParameter parameterEmail = new SqlParameter("@Email", SqlDbType.NVarChar, 50);
parameterEmail.Direction = ParameterDirection.Output;
myCommand.Parameters.Add(parameterEmail);

SqlParameter parameterPassword = new SqlParameter("@Password", SqlDbType.NVarChar, 50);
parameterPassword.Direction = ParameterDirection.Output;
myCommand.Parameters.Add(parameterPassword);

myConnection.Open();
myCommand.ExecuteNonQuery();
myConnection.Close();

// Create CustomerDetails Struct
CustomerDetails myCustomerDetails = new CustomerDetails();

// Populate Struct using Output Params from SPROC
myCustomerDetails.FullName = (string)parameterFullName.Value;
myCustomerDetails.Password = (string)parameterPassword.Value;
myCustomerDetails.Email = (string)parameterEmail.Value;

return myCustomerDetails;
}

//************************************************** *****
//
// CustomersDB.AddCustomer() Method <a name="AddCustomer"></a>
//
// The AddCustomer method inserts a new customer record
// into the customers database. A unique "CustomerId"
// key is then returned from the method. This can be
// used later to place orders, track shopping carts,
// etc within the ecommerce system.
//
// Other relevant sources:
// + CustomerAdd Stored Procedure
//
//************************************************** *****

public String AddCustomer(string fullName, string email, string password)
{

// Create Instance of Connection and Command Object
SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
SqlCommand myCommand = new SqlCommand("CMRC_CustomerAdd", myConnection);

// Mark the Command as a SPROC
myCommand.CommandType = CommandType.StoredProcedure;

// Add Parameters to SPROC
SqlParameter parameterFullName = new SqlParameter("@FullName", SqlDbType.NVarChar, 50);
parameterFullName.Value = fullName;
myCommand.Parameters.Add(parameterFullName);

SqlParameter parameterEmail = new SqlParameter("@Email", SqlDbType.NVarChar, 50);
parameterEmail.Value = email;
myCommand.Parameters.Add(parameterEmail);

SqlParameter parameterPassword = new SqlParameter("@Password", SqlDbType.NVarChar, 50);
parameterPassword.Value = password;
myCommand.Parameters.Add(parameterPassword);

SqlParameter parameterCustomerID = new SqlParameter("@CustomerID", SqlDbType.Int, 4);
parameterCustomerID.Direction = ParameterDirection.Output;
myCommand.Parameters.Add(parameterCustomerID);

try {
myConnection.Open();
myCommand.ExecuteNonQuery();
myConnection.Close();

// Calculate the CustomerID using Output Param from SPROC
int customerId = (int)parameterCustomerID.Value;

return customerId.ToString();
}
catch {
return String.Empty;
}
}

//************************************************** *****
//
// CustomersDB.Login() Method <a name="Login"></a>
//
// The Login method validates a email/password pair
// against credentials stored in the customers database.
// If the email/password pair is valid, the method returns
// the "CustomerId" number of the customer. Otherwise
// it will throw an exception.
//
// Other relevant sources:
// + CustomerLogin Stored Procedure
//
//************************************************** *****

public String Login(string email, string password)
{

// Create Instance of Connection and Command Object
SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
SqlCommand myCommand = new SqlCommand("CMRC_CustomerLogin", myConnection);

// Mark the Command as a SPROC
myCommand.CommandType = CommandType.StoredProcedure;

// Add Parameters to SPROC
SqlParameter parameterEmail = new SqlParameter("@Email", SqlDbType.NVarChar, 50);
parameterEmail.Value = email;
myCommand.Parameters.Add(parameterEmail);

SqlParameter parameterPassword = new SqlParameter("@Password", SqlDbType.NVarChar, 50);
parameterPassword.Value = password;
myCommand.Parameters.Add(parameterPassword);

SqlParameter parameterCustomerID = new SqlParameter("@CustomerID", SqlDbType.Int, 4);
parameterCustomerID.Direction = ParameterDirection.Output;
myCommand.Parameters.Add(parameterCustomerID);

// Open the connection and execute the Command
myConnection.Open();
myCommand.ExecuteNonQuery();
myConnection.Close();

int customerId = (int)(parameterCustomerID.Value);

if (customerId == 0) {
return null;
}
else {
return customerId.ToString();
}
}
}
}