/// <summary>
/// Event Handler for click event on btnAdd which adds a new student in database
/// </summary>
/// <param name="sender">Control on which event occured</param>
/// <param name="e">Args for event occured</param>
protected void btnAdd_Click(object sender, EventArgs e)
{
//getting the entered information
string fullname = txtFullName.Text;
string fathersName = txtFathersName.Text;
int rollNo = Convert.ToInt32(txtRollNo.Text);
int age = Convert.ToInt16(txtAge.Text);
int stream = Convert.ToInt32(listStream.SelectedValue);
string address = txtAddress.Text;
int state = Convert.ToInt32(listState.SelectedValue);
//calling AddStudent() method to add the record to database
StudentDataHandler studHandler = new StudentDataHandler();
bool result = studHandler.AddStudent(fullname, fathersName, rollNo, age, stream, address, state);
if (result)
{
//if record gets added
Response.Write(Messages.RecordAddSuccess);
resetControls(); //resetting the controls for new student
}
else
{
//if record adding failed.
Response.Write(Messages.RecordAddFailed);
}
}
/// <summary>
/// CLick Event Handler for btnUpdate button to update record of a student
/// </summary>
/// <param name="source">Control attribute on which this event has occured</param>
/// <param name="args">Event Args for the control</param>
protected void btnUpdate_Click(object sender, EventArgs e)
{
//getting the newly entered data for student
string fullname = txtFullName.Text;
string fathersName = txtFathersName.Text;
int rollNo = Convert.ToInt32(txtRollNo.Text);
int age = Convert.ToInt16(txtAge.Text);
int stream = Convert.ToInt32(listStream.SelectedValue);
string address = txtAddress.Text;
int state = Convert.ToInt32(listState.SelectedValue);
//updating the Student object
stud.FullName = fullname;
stud.FathersName = fathersName;
stud.RollNo = rollNo;
stud.Age = age;
stud.Stream = stream;
stud.Address = address;
stud.State = state;
//calling the update method
bool result = StudentDataHandler.UpdateStudent(stud);
if (result)
{
// if result gets updated
Response.Write(Messages.RecordUpdateSuccess);
}
else
{
//if updation gets failed.
Response.Write(Messages.RecordUpdateFailed);
}
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
//checking whether there is any querystring or not
if (Request.QueryString.Count == 0)
{
//Redirecting to AllStudents page to select a student to update
Response.Redirect("AllStudents.aspx");
}
AddStreams(); //to add streams to the respective listBox
AddStates(); //to add states to the respective listBox
//extracting the student ID from query string
string queryData = Request.QueryString["StudID"];
int studID = Convert.ToInt32(queryData);
//getting the Student record from the database
stud = StudentDataHandler.FindStudent(studID);
//filling up the controls with the old data
txtFullName.Text = stud.FullName;
txtFathersName.Text = stud.FathersName;
txtRollNo.Text = stud.RollNo.ToString();
txtAge.Text = stud.Age.ToString();
listStream.SelectedValue = stud.Stream.ToString();
string address = txtAddress.Text = stud.Address;
listState.SelectedValue = stud.State.ToString();
}
}
/// <summary>
/// SelctIndexChanged Event Handler for listStream to show the students from the selected stream
/// </summary>
/// <param name="sender">Control on which the event occured</param>
/// <param name="e">Args for the event occured.</param>
protected void listStream_SelectedIndexChanged(object sender, EventArgs e)
{
//creating a new DataTable for GridView
DataTable studTable = new DataTable();
//settign the columns for the table
studTable.Columns.Add("StudID", typeof(int));
studTable.Columns.Add("FullName", typeof(string));
studTable.Columns.Add("FathersName", typeof(string));
studTable.Columns.Add("RollNo", typeof(int));
studTable.Columns.Add("Age", typeof(int));
studTable.Columns.Add("Stream", typeof(string));
studTable.Columns.Add("Address", typeof(string));
studTable.Columns.Add("State", typeof(string));
//reading the data from database
List <Student> students = StudentDataHandler.ListAllStudent();
if (listStream.SelectedIndex == 0) //if user selects 'All'
{
//adding rows to the DataTable
foreach (Student item in students)
{
studTable.Rows.Add(
item.StudID,
item.FullName,
item.FathersName,
item.RollNo,
item.Age,
UtilityFunctions.GetStreamName(item.Stream),
item.Address,
UtilityFunctions.GetStateName(item.State)
);
}
}
else //if user selects a specific stream
{
//adding rows to the DataTable
foreach (Student item in students)
{
if (item.Stream == Convert.ToInt32(listStream.SelectedValue))
{
studTable.Rows.Add(
item.StudID,
item.FullName,
item.FathersName,
item.RollNo,
item.Age,
UtilityFunctions.GetStreamName(item.Stream),
item.Address,
UtilityFunctions.GetStateName(item.State)
);
}
}
}
//setting up the DataSource for the GridView
gridStudents.DataSource = studTable;
gridStudents.DataBind();
}
/// <summary>
/// SelectedIndexChanged Event Handler for listStreams
/// </summary>
/// <param name="sender">lisStream object</param>
/// <param name="e">Args for event</param>
protected void listStreams_SelectedIndexChanged(object sender, EventArgs e)
{
//reading the data from database
List <Student> students = StudentDataHandler.ListAllStudent();
listStudLeft.Items.Clear();
listStudRight.Items.Clear();
if (listStreams.SelectedIndex == 0) //if user selects 'All'
{
//adding rows to the DataTable
foreach (Student item in students)
{
listStudLeft.Items.Add(new ListItem(item.FullName, item.RollNo.ToString()));
}
}
else //if user selects a specific stream
{
//adding rows to the DataTable
foreach (Student item in students)
{
if (item.Stream == Convert.ToInt32(listStreams.SelectedValue))
{
listStudLeft.Items.Add(new ListItem(item.FullName, item.RollNo.ToString()));
}
}
}
}
public static string DeleteStudents(string rollNos)
{
string result = Messages.RecordDeletedFailed;
if (StudentDataHandler.DeleteStudent(rollNos))
{
result = Messages.RecordDeletedSuccess;
}
return(result);
}
