public void ModifyMethod()
{
if (selectedCustomer != null)
{
ModifyView change = new ModifyView();
Messenger.Default.Send(new MessageMember(selectedCustomer, "edit"));
change.Show();
}
}
public MainViewModel()
{
ButtonIsEnabled = false;
//Message receivers to accept messages from EditViewModel and AddViewModel
//The sender also sends a token as the second parameter and only receivers with the same token will accept it.
Messenger.Default.Register <Customer>(this, "add", (customer) =>
{
try
{
// Code a query to retrieve the selected customer
// and store the Customer object in the class variable.
selectedCustomer = customer;
CustomerIDBox = Convert.ToString(customer.CustomerID);
this.DisplayCustomer();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
});
Messenger.Default.Register <Customer>(this, "modify", (customer) =>
{
try
{
// Code a query to retrieve the selected customer
// and store the Customer object in the class variable.
selectedCustomer = customer;
this.DisplayCustomer();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
});
Messenger.Default.Register <Customer>(this, "modData", (customer) =>
{
SelectedCustomer.Name = customer.Name;
SelectedCustomer.Address = customer.Address;
SelectedCustomer.City = customer.City;
SelectedCustomer.State = customer.State;
SelectedCustomer.ZipCode = customer.ZipCode;
});
Messenger.Default.Register <Customer>(this, "clear", (customer) =>
{
this.ClearControls();
});
Messenger.Default.Register <Customer>(this, "reload", (customer) =>
{
this.GetCustomer(customer.CustomerID);
});
/// <summary>
/// Get the customer using the customer ID.
/// </summary>
GetCustomerCommand = new RelayCommand(() =>
{
if (Validator.IsPresent(CustomerIDBox) &&
Validator.IsInt32(CustomerIDBox))
{
int customerID = Convert.ToInt32(CustomerIDBox);
this.GetCustomer(customerID);
}
});
/// <summary>
/// Open the add customer view.
/// </summary>
AddCustomerCommand = new RelayCommand(() =>
{
AddView addView = new AddView();
addView.Show();
ButtonIsEnabled = true;
});
/// <summary>
/// Open the modify customer view.
/// </summary>
ModifyCustomerCommand = new RelayCommand(() =>
{
ModifyView modView = new ModifyView();
Messenger.Default.Send(SelectedCustomer, "mod");
modView.Show();
});
/// <summary>
/// Delete a customer from the database.
/// </summary>
DeleteCustomerCommand = new RelayCommand(() =>
{
try
{
// Mark the row for deletion.
// Update the database.
MMABooksEntity.mmaBooks.Customers.Remove(selectedCustomer);
MMABooksEntity.mmaBooks.SaveChanges();
Messenger.Default.Send(new NotificationMessage("Customer Removed!"));
CustomerIDBox = "";
this.ClearControls();
}
// Add concurrency error handling.
// Place the catch block before the one for a generic exception.
catch (DbUpdateConcurrencyException ex)
{
ex.Entries.Single().Reload();
if (MMABooksEntity.mmaBooks.Entry(selectedCustomer).State == EntityState.Detached)
{
MessageBox.Show("Another user has deleted " + "that customer.", "Concurrency Error");
CustomerIDBox = "";
this.ClearControls();
}
else
{
MessageBox.Show("Another user has updated " + "that customer.", "Concurrency Error");
DisplayCustomer();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
ButtonIsEnabled = false;
});
/// <summary>
/// Close the current window.
/// </summary>
CloseWindowCommand = new RelayCommand <MainWindow>((window) =>
{
if (window != null)
{
window.Close();
}
});
}
