private void GetCustomer(int CustomerID)
{
try
{
// Code a query to retrieve the selected customer
// and store the Customer object in the class variable.
// Note to self: LINQ query is bottom-up.
selectedCustomer = entities.Customers
.Where(cust => cust.CustomerID == CustomerID)
.Select(cust => cust).Single();
if (selectedCustomer == null)
{
MessageBox.Show("No customer found with this ID. " +
"Please try again.", "Customer Not Found");
this.ClearControls();
txtCustomerID.Focus();
}
else
{
// If the customer is found, add code to the GetCustomer method that checks if the State object
// has been loaded and that loads if it hasn't.
if (!entities.Entry(selectedCustomer).Reference("State").IsLoaded)
{
entities.Entry(selectedCustomer).Reference("State").Load();
}
this.DisplayCustomer();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
}
private void btnAccept_Click(object sender, EventArgs e)
{
if (IsValidData())
{
if (addCustomer)
{
customer = new Customer();
this.PutCustomerData(customer);
// Add the new vendor to the collection of vendors.
encontext.Customers.Add(customer);
encontext.SaveChanges();
try
{
this.DialogResult = DialogResult.OK;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
}
else
{
this.PutCustomerData(customer);
try
{
// Update the database.
encontext.SaveChanges();
this.DialogResult = DialogResult.OK;
}
catch (DbUpdateConcurrencyException ex)
{
ex.Entries.Single().Reload();
if (encontext.Entry(customer).State
== EntityState.Detached)
{
MessageBox.Show("Another user has deleted that customer.",
"Concurrency Error");
this.DialogResult = DialogResult.Abort;
}
else
{
MessageBox.Show("Another user has updated that customer.",
"Concurrency Error");
this.DialogResult = DialogResult.Retry;
}
}
// Add concurrency error handling.
// Place the catch block before the one for a generic exception.
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
}
}
}