private void deleteBtn_Click(object sender, EventArgs e)
{
KevinTB learner;
int deletingId = int.Parse(learnerIDTb.Text);
//Get learner for the given learnerId
using (var dbContext = new KevinDBEntities())
{
learner = dbContext.KevinTBs
.Where(l => l.learnerID == deletingId)
.FirstOrDefault <KevinTB>();
}
// Create new context for disconnected scenario
using (var dbContext = new KevinDBEntities())
{
dbContext.Entry(learner).State = EntityState.Deleted;
// Save changes to database
dbContext.SaveChanges();
}
MessageBox.Show($"{learner.learnerName} has been deleted");
this.loadUnfilteredResults();
this.resetFormControls();
}
private void addBtn_Click(object sender, EventArgs e)
{
using (var dbContext = new KevinDBEntities())
{
try
{
//create an instance of the Entity object
KevinTB learner = new KevinTB
{
learnerID = int.Parse(learnerIDTb.Text),
learnerName = learnerNameTb.Text,
enrolledProgram = enrolledProgramTb.Text,
favoriteSubject = favSubTb.Text,
numberOfLanguages = int.Parse(numLangTb.Text),
strongestSkill = strongSkillTb.Text
};
//adds the given entity to the context underlying the set
dbContext.KevinTBs.Add(learner);
dbContext.Entry(learner).State = EntityState.Added;
//save dbContext - also save data to the db
dbContext.SaveChanges();
MessageBox.Show($"Added new learner to the directory: {learner.learnerName}");
this.loadUnfilteredResults();
this.resetFormControls();
}
catch (Exception)
{
MessageBox.Show($"LearnerID and Number of Languages must be positive integer numbers!");
}
}
}
/// <summary>
/// Fills the kevinTBBindingSource with all rows, ordered by learnerID
/// </summary>
private void loadUnfilteredResults()
{
using (var dbContext = new KevinDBEntities())
{
//load kevintb table ordered by learnerid
dbContext.KevinTBs
.OrderBy(learner => learner.learnerID)
.Load();
//specify DataSource for kevinTBBindingSource
kevinTBBindingSource.DataSource = dbContext.KevinTBs.Local;
kevinTBBindingSource.MoveFirst(); // go to first result
}
}
private void searchBtn_Click(object sender, EventArgs e)
{
using (var dbContext = new KevinDBEntities())
{
var filteredResults = from learner in dbContext.KevinTBs
where learner.enrolledProgram.Equals(searchTb.Text)
select new
{
learner.learnerID,
learner.learnerName,
learner.enrolledProgram
};
kevinTBBindingSource.DataSource = filteredResults.ToList();
kevinTBBindingSource.MoveFirst();
this.resetFormControls();
}
}
private void updateBtn_Click(object sender, EventArgs e)
{
KevinTB learner;
int updatingId = int.Parse(learnerIDTb.Text);
//Get learner for the given learnerId
using (var dbContext = new KevinDBEntities())
{
learner = dbContext.KevinTBs
.Where(l => l.learnerID == updatingId)
.FirstOrDefault <KevinTB>();
}
// Update learner info in disconnected mode (out of dbContext scope)
try
{
learner.learnerID = int.Parse(learnerIDTb.Text);
learner.learnerName = learnerNameTb.Text;
learner.enrolledProgram = enrolledProgramTb.Text;
learner.favoriteSubject = favSubTb.Text;
learner.numberOfLanguages = int.Parse(numLangTb.Text);
learner.strongestSkill = strongSkillTb.Text;
}
catch (Exception)
{
MessageBox.Show($"LearnerID and Number of Languages must be positive integer numbers!");
}
// Save modified entity using new Context
using (var dbContext = new KevinDBEntities())
{
// Mark entity as modified
dbContext.Entry(learner).State = EntityState.Modified;
// Save changes to database
dbContext.SaveChanges();
}
MessageBox.Show($"{learner.learnerName} has been updated");
this.loadUnfilteredResults();
this.resetFormControls();
}
private void kevinTBDataGridView_CellClick(object sender, DataGridViewCellEventArgs e)
{
KevinTB learner;
int selectedId = int.Parse(kevinTBDataGridView.SelectedRows[0].Cells[0].Value.ToString());
//Get learner for the given learnerId
using (var dbContext = new KevinDBEntities())
{
learner = dbContext.KevinTBs
.Where(l => l.learnerID == selectedId)
.FirstOrDefault <KevinTB>();
}
learnerIDTb.Text = learner.learnerID.ToString();
learnerNameTb.Text = learner.learnerName;
enrolledProgramTb.Text = learner.enrolledProgram;
favSubTb.Text = learner.favoriteSubject;
numLangTb.Text = learner.numberOfLanguages.ToString();
strongSkillTb.Text = learner.strongestSkill.ToString();
currentlyEditing = true;
learnerIDTb.Enabled = false;
addBtn.Enabled = false;
}
/// <summary>
/// Fills the kevinTBBindingSource with all rows, ordered by learnerID
/// </summary>
private void _refreshContacts()
{
//dispose of old dbContext, if any
if (dbContext != null)
{
dbContext.Dispose();
}
// create new DbContext so we can reorder records based on edits
dbContext = new KevinDBEntities();
//enables the save button
kevinTBBindingNavigatorSaveItem.Enabled = true;
//load KevinTB table ordered by learnerID
dbContext.KevinTBs
.OrderBy(learner => learner.learnerID)
.Load();
//specify DataSource for kevinTBBindingSource
kevinTBBindingSource.DataSource = dbContext.KevinTBs.Local;
kevinTBBindingSource.MoveFirst(); // go to first result
searchTextBox.Clear();
}
