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($"LearnerID and Number of Languages must be positive integer numbers!");
}
}
}
private void kevinTBBindingNavigatorSaveItem_Click(object sender, EventArgs e)
{
Validate(); //validate the input fields
kevinTBBindingSource.EndEdit();
//try to save the changes
try
{
dbContext.SaveChanges();//write changes to underlying db
}
catch (System.Data.Entity.Validation.DbEntityValidationException)
{
MessageBox.Show("Learner ID, Learner Name and Enrolled Programs must contain values", "Entity Validation Exception");
}
this._refreshContacts(); //change back to unfiltered data
}
private void updateBtn_Click(object sender, EventArgs e)
{
KevinTB learner;
int updatingId = int.Parse(learnerIDTb.Text);
//Get learner for the given learnerId
using (var dbContext = new KevinDBEntities())
{
learner = dbContext.KevinTBs
.Where(l => l.learnerID == updatingId)
.FirstOrDefault <KevinTB>();
}
// Update learner info in disconnected mode (out of dbContext scope)
try
{
learner.learnerID = int.Parse(learnerIDTb.Text);
learner.learnerName = learnerNameTb.Text;
learner.enrolledProgram = enrolledProgramTb.Text;
learner.favoriteSubject = favSubTb.Text;
learner.numberOfLanguages = int.Parse(numLangTb.Text);
learner.strongestSkill = strongSkillTb.Text;
}
catch (Exception)
{
MessageBox.Show($"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();
}
