// This method simulates access to a remote database over a slow
// network.
internal void LoadCustomers()
{
int i;
for (i=0; i < _initialMaxCustomers; i++)
{
// Simulate slow network access.
System.Threading.Thread.Sleep (1000);
// Create and add the customer.
Customer customer = new Customer();
_customerList.Add (customer);
// Shows the user status of obtaining the recordset.
Console.Write(".");
}
Console.WriteLine ("\nLoadCustomers: Loaded {0} customers from the database.", i);
}
private void AddNewCustomer()
{
// Create a new customer record. This will create a new customer
// number.
Customer c = new Customer();
// Create an instance of the delegate used to read the
// data across the slow network.
CustomerDataManager.DataAdder adder = new CustomerDataManager.DataAdder(_manager.Add);
// Create the delegate that will be used to call
// the callback method above.
AsyncCallback addResults = new AsyncCallback(AddingDone);
// We could have called the delegate directly: reader();. However,
// we want to do it asynchronously so well use the BeginInvoke()
// method in the delegate instead. This call will return immediately.
IAsyncResult iar = adder.BeginInvoke(c, addResults, null);
}
internal bool Add(Customer newCustomer)
{
bool success = true;
// First, make sure the customer ID isn't already in the list.
foreach (Customer c in _customerList)
{
if (c.CustomerNumber == newCustomer.CustomerNumber)
{
Console.WriteLine ("Add: ERROR - Customer with I.D. {0} already exists.",
newCustomer.CustomerNumber);
success = false;
}
}
if (success)
{
// Simulate a slow network.
System.Threading.Thread.Sleep (7500);
// Add the customer to the list.
_customerList.Add (newCustomer);
// Reset the current index so that we're pointing to
// the top of the list of customers.
First();
}
return success;
}
private void AddNewCustomer()
{
Customer c = new Customer();
if (!_manager.Add(c))
{
Console.WriteLine ("Run: ERROR - Could not add customer {0}.", c.CustomerNumber);
}
else
{
Console.WriteLine ("Run: Customer {0} was successfully added.", c.CustomerNumber);
}
}