/// <summary>
/// Handles changes for all fields except contact as contact in this case
/// is a derived class used to represent data from a child class, contact title
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void gridView_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
/*
* We need to know which column the current cell name is to set properties
* below
*/
var currentColumnName = gridView.CurrentCell.OwningColumn.Name;
var customerEntity = _customersBindingSource.CurrentCustomerEntity();
var customer = context.Customers
.FirstOrDefault(cust =>
cust.CustomerIdentifier == customerEntity.CustomerIdentifier);
/*
* Handle DataGridViewComboBox columns
*
* IMPORTANT: Here FirstOrDefault is used without checking if the returning
* item is null or not, for your project check for null.
*/
try
{
if (currentColumnName == "ContactTitleColumn")
{
// ReSharper disable once PossibleNullReferenceException
var contactTitleIdentifier = context.ContactTypes
.FirstOrDefault(contactType => contactType.ContactTitle == gridView.EditingControl.Text)
.ContactTypeIdentifier;
context.Entry(customer).Property(x => x.ContactTypeIdentifier)
.CurrentValue = contactTitleIdentifier;
}
else if (currentColumnName == "CountyNameColumn")
{
var countryIdentifier = context.Countries
.FirstOrDefault(country => country.Name == gridView.EditingControl.Text)
.CountryIdentifier;
context.Entry(customer).Property(x => x.CountryIdentifier)
.CurrentValue = countryIdentifier;
}
else
{
context.Entry(customer).Property(gridView.CurrentCell.OwningColumn.DataPropertyName)
.CurrentValue = gridView.EditingControl.Text;
}
}
catch (Exception ex)
{
/*
* rule violations e.g. max length exceeded, required field empty
* which would be annotated on class properties used to communicate
* with tables in the database.
*/
MessageBox.Show(ex.Message);
}
}
/// <summary>
/// Demo get only changed fields
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button1_Click(object sender, EventArgs e)
{
var item = view.FirstOrDefault(c => c.CustomerIdentifier == 4);
var entry = context.Entry(item);
if (entry.State != EntityState.Modified)
{
return;
}
//CheckIfDifferent(entry);
var originalEntity = context.Customers.AsNoTracking()
.FirstOrDefault(me => me.CustomerIdentifier == item.CustomerIdentifier);
Console.WriteLine();
foreach (var propertyName in entry.CurrentValues.PropertyNames)
{
//Console.WriteLine("Property Name: {0}", propertyName);
//get original value
var orgVal = entry.OriginalValues[propertyName];
//Console.WriteLine(" Original Value: {0}", orgVal);
//get current values
var curVal = entry.CurrentValues[propertyName];
//Console.WriteLine(" Current Value: {0}", curVal);
if (!orgVal.Equals(curVal))
{
Console.WriteLine($"{propertyName} -> {orgVal} - {curVal}");
}
}
}
