protected void AssignCourseButton_Click(object sender, EventArgs e)
{
using (var context = new SchoolEntities())
{
var instructorID = Convert.ToInt32(InstructorsDropDownList.SelectedValue);
var instructor = (from p in context.People
where p.PersonID == instructorID
select p).First();
var courseID = Convert.ToInt32(UnassignedCoursesDropDownList.SelectedValue);
var course = (from c in context.Courses
where c.CourseID == courseID
select c).First();
instructor.Courses.Add(course);
try
{
context.SaveChanges();
PopulateDropDownLists();
CourseAssignedLabel.Text = "Assignment successful.";
}
catch (Exception)
{
CourseAssignedLabel.Text = "Assignment unsuccessful.";
//Add code to log the error.
}
CourseAssignedLabel.Visible = true;
}
}
protected void RemoveCourseButton_Click(object sender, EventArgs e)
{
using (var context = new SchoolEntities())
{
var instructorID = Convert.ToInt32(InstructorsDropDownList.SelectedValue);
var instructor = (from p in context.People
where p.PersonID == instructorID
select p).First();
var courseID = Convert.ToInt32(AssignedCoursesDropDownList.SelectedValue);
var courses = instructor.Courses;
var courseToRemove = new Course();
foreach (Course c in courses)
{
if (c.CourseID == courseID)
{
courseToRemove = c;
break;
}
}
try
{
courses.Remove(courseToRemove);
context.SaveChanges();
PopulateDropDownLists();
CourseRemovedLabel.Text = "Removal successful.";
}
catch (Exception)
{
CourseRemovedLabel.Text = "Removal unsuccessful.";
//Add code to log the error.
}
CourseRemovedLabel.Visible = true;
}
}
protected void ExecuteButton_Click(object sender, EventArgs e)
{
using (SchoolEntities context = new SchoolEntities())
{
RowsAffectedLabel.Text = context.ExecuteStoreCommand("UPDATE Course SET Credits = Credits * {0}", CreditsMultiplierTextBox.Text).ToString();
}
}
protected void InstructorsGridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
using (var context = new SchoolEntities())
{
var instructorBeingUpdated = Convert.ToInt32(e.Keys[0]);
var officeAssignment = (from o in context.OfficeAssignments
where o.InstructorID == instructorBeingUpdated
select o).FirstOrDefault();
try
{
if (String.IsNullOrWhiteSpace(instructorOfficeTextBox.Text) == false)
{
if (officeAssignment == null)
{
context.OfficeAssignments.AddObject(
OfficeAssignment.CreateOfficeAssignment(
instructorBeingUpdated, instructorOfficeTextBox.Text, null));
}
else
{
officeAssignment.Location = instructorOfficeTextBox.Text;
}
}
else
{
if (officeAssignment != null)
{
context.DeleteObject(officeAssignment);
}
}
context.SaveChanges();
}
catch (Exception)
{
e.Cancel = true;
ErrorMessageLabel.Visible = true;
ErrorMessageLabel.Text = "Update failed.";
//Add code to log the error.
}
}
}
private void PopulateDropDownLists()
{
using (var context = new SchoolEntities())
{
var allCourses = context.GetCourses().ToList();
var instructorID = Convert.ToInt32(InstructorsDropDownList.SelectedValue);
var instructor = (from p in context.People.Include("Courses")
where p.PersonID == instructorID
select p).First();
var assignedCourses = instructor.Courses.AsEnumerable();
var unassignedCourses = allCourses.Except(assignedCourses.AsEnumerable()).ToList();
UnassignedCoursesDropDownList.DataSource = unassignedCourses;
UnassignedCoursesDropDownList.DataBind();
UnassignedCoursesDropDownList.Visible = true;
AssignedCoursesDropDownList.DataSource = assignedCourses;
AssignedCoursesDropDownList.DataBind();
AssignedCoursesDropDownList.Visible = true;
}
}
