protected void btnSave_Click(object sender, EventArgs e)
{
try
{
//use EF to connect to SQL Server
using (DefaultConnection db = new DefaultConnection())
{
//use the Student model to save the new record
Student s = new Student();
Int32 StudentID = 0;
//check the querystring for an id so we can determine add / update
if (Request.QueryString["StudentID"] != null)
{
//get the id from the url
StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
//get the current student from EF
s = (from objS in db.Students
where objS.StudentID == StudentID
select objS).FirstOrDefault();
}
s.LastName = txtLastName.Text;
s.FirstMidName = txtFirstMidName.Text;
s.EnrollmentDate = Convert.ToDateTime(txtEnrollmentDate.Text);
//call add only if we have no student ID
if (StudentID == 0)
{
db.Students.Add(s);
}
//run the update or insert
db.SaveChanges();
//redirect to the updated students page
Response.Redirect("students.aspx");
}
}
catch (Exception ex)
{
//redirect
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//create a new course and fill the properties
Course objC = new Course();
objC.Title = txtTitle.Text;
objC.Credits = Convert.ToInt32(txtCredits.Text);
objC.DepartmentID = Convert.ToInt32(ddlDepartment.SelectedValue);
//save
db.Courses.Add(objC);
db.SaveChanges();
//redirect
Response.Redirect("courses.aspx");
}
}
protected void grdDepartments_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//identify the DepartmentID to be deleted from the row the user selected
Int32 DepartmentID = Convert.ToInt32(grdDepartments.DataKeys[e.RowIndex].Values["DepartmentID"]);
//connect
using (DefaultConnection db = new DefaultConnection())
{
Department dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
//delete
db.Departments.Remove(dep);
db.SaveChanges();
//refresh grid
GetDepartments();
}
}
protected void btnRegister_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//create a new instructor
Instructor objI = new Instructor();
//fill the properties from the form inputs
objI.FirstName = txtFirstName.Text;
objI.LastName = txtLastName.Text;
objI.Username = txtUsername.Text;
objI.DepartmentID = Convert.ToInt32(ddlDepartment.SelectedValue);
//salt and hash the plain text password
String password = txtPassword.Text;
String salt = CreateSalt(8);
String pass_and_salt = password + salt;
// Create a new instance of the hash crypto service provider.
HashAlgorithm hashAlg = new SHA256CryptoServiceProvider();
// Convert the data to hash to an array of Bytes.
byte[] bytValue = System.Text.Encoding.UTF8.GetBytes(pass_and_salt);
// Compute the Hash. This returns an array of Bytes.
byte[] bytHash = hashAlg.ComputeHash(bytValue);
// Optionally, represent the hash value as a base64-encoded string,
// For example, if you need to display the value or transmit it over a network.
string base64 = Convert.ToBase64String(bytHash);
objI.Password = base64;
objI.Salt = salt;
//save
db.Instructors.Add(objI);
db.SaveChanges();
}
}
protected void btnSave_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//create a new department in memory
Department dep = new Department();
Int32 DepartmentID = 0;
//check for a url
if (!String.IsNullOrEmpty(Request.QueryString["DepartmentID"]))
{
//get the id from the url
DepartmentID = Convert.ToInt32(Request.QueryString["DepartmentID"]);
//look up the department
dep = (from d in db.Departments
where d.DepartmentID == DepartmentID
select d).FirstOrDefault();
}
//fill the properties of the new department
dep.Name = txtName.Text;
dep.Budget = Convert.ToDecimal(txtBudget.Text);
//add if we have no id in the url
if (DepartmentID == 0)
{
db.Departments.Add(dep);
}
//save the new department
db.SaveChanges();
//redirect to the departments list page
Response.Redirect("departments.aspx");
}
}
protected void grdStudents_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//store which row was clicked
Int32 selectedRow = e.RowIndex;
//get the selected StudentID using the grid's Data Key collection
Int32 StudentID = Convert.ToInt32(grdStudents.DataKeys[selectedRow].Values["StudentID"]);
//use EF to remove the selected student from the db
using (DefaultConnection db = new DefaultConnection())
{
Student s = (from objS in db.Students
where objS.StudentID == StudentID
select objS).FirstOrDefault();
//do the delete
db.Students.Remove(s);
db.SaveChanges();
}
//refresh the grid
GetStudents();
}
protected void btnAdd_Click(object sender, EventArgs e)
{
//connect
using (DefaultConnection db = new DefaultConnection())
{
//instantiate a new enrollment
Enrollment objE = new Enrollment();
objE.StudentID = Convert.ToInt32(Request.QueryString["StudentID"]);
objE.CourseID = Convert.ToInt32(ddlCourse.SelectedValue);
//save
db.Enrollments.Add(objE);
db.SaveChanges();
//refresh courses grid
GetEnrollments();
//reset the dropdowns
ddlDepartment.ClearSelection();
ddlCourse.ClearSelection();
}
}
protected void grdCourses_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//get selected record id
Int32 EnrollmentID = Convert.ToInt32(grdCourses.DataKeys[e.RowIndex].Values["EnrollmentID"]);
using (DefaultConnection db = new DefaultConnection())
{
//get selected record
Enrollment objE = (from en in db.Enrollments
where en.EnrollmentID == EnrollmentID
select en).FirstOrDefault();
//delete
db.Enrollments.Remove(objE);
db.SaveChanges();
//refresh the data on the page
GetStudent();
//reattach js delete confirmation
}
}