private List <string> currentLogins = new List <string>(); //maintains a list of currently logged in students
//would be nice if this wasn't global
/*
* This function returns the listbox to a full sorted list of all students in the database
* Much like the other options that take advantage of Valid class SQL queries the
* performance of this will depend on the student database being maintained as students
* graduate
*/
private void OpenFill()
{
nameListBox.Items.Clear();
Valid openFill = new Valid();
List <string> studentNames = new List <string>(openFill.StudentSearch("%"));
studentNames.Sort();
if (studentNames.Count > 0)
{
for (int i = 0; i < studentNames.Count; i++)
{
nameListBox.Items.Add(studentNames[i]);
}
}
}
/*
* This OpenFill method is functionally similar to the other listbox filling methods throughout
* the forms, the key difference being this also populates the listbox with StudentIDs for
* clarity in the removal process
*/
private void OpenFill() //populates the student list with the full database of students
{
studentListBox.Items.Clear();
Valid openFill = new Valid();
List <string> studentNames = new List <string>(openFill.StudentSearch("%", true));
if (studentNames.Count > 0)
{
for (int i = 0; i < studentNames.Count; i++)
{
string[] student = studentNames[i].Split(',');
studentListBox.Items.Add(student[0].Trim() + ", " + student[1].Trim() + ", " + Utility.Decrypt(student[2], false).Trim());
}
}
}
/*
* The following region is used to update the student name listbox for faster logins
* It queries the database on text change to match users
* The size of the DB could cause this function to run slowly if old users aren't pruned
*
* The first section is designed to escape apostrophes in user names to not interfere with
* SQL queries
* The try block uses a function of the Valid class to retrieve all student entries that
* partial match the last name entered
*/
#region ListBoxUpdater
private void textBox1_TextChanged(object sender, EventArgs e)
{
string name = textBox1.Text;
if (name.Length == 0)
{
name = "%";
}
if (name.Length > 1)
{
if (name.Contains("'"))
{
for (int i = 0; i < name.Length; i++)
{
if (name[i] == '\'')
{
name = name.Insert(i, "\'");
i++;
}
}
}
}
else if (name.Length == 1 && name == "\'")
{
name += "'";
}
try
{
nameListBox.Items.Clear();
Valid students = new Valid();
List <string> studentNames = new List <string>(students.StudentSearch(name));
studentNames.Sort();
if (studentNames.Count > 0)
{
for (int i = 0; i < studentNames.Count; i++)
{
nameListBox.Items.Add(studentNames[i]);
}
}
}
catch (Exception ex)
{
MessageBox.Show("Something is broken in the list fill.", ex.Message);
}
//nameListBox.BeginUpdate
}
/*
* This event handler filters the student list in the same way as the StudentLogin form
* It carries the same restriction of only filtering by last name
*/
private void searchBox_TextChanged(object sender, EventArgs e)
{
string name = searchBox.Text;
if (name.Length == 0) //sends a wildcard to the database for a full list when the search box is empty
{
name = "%";
}
if (name.Length > 1) //escape sequence for names with apostrophes
{
if (name.Contains("'"))
{
for (int i = 0; i < name.Length; i++)
{
if (name[i] == '\'')
{
name = name.Insert(i, "\'");
i++;
}
}
}
}
else if (name.Length == 1 && name == "\'")
{
name += "'";
}
try
{
studentListBox.Items.Clear();
Valid students = new Valid();
List <string> studentNames = new List <string>(students.StudentSearch(name, true));
if (studentNames.Count > 0)
{
for (int i = 0; i < studentNames.Count; i++)
{
string[] student = studentNames[i].Split(',');
studentListBox.Items.Add(student[0].Trim() + ", " + student[1].Trim() + ", " + Utility.Decrypt(student[2], false).Trim());
}
}
}
catch (Exception ex)
{
MessageBox.Show("Something is broken in the list fill.", ex.Message);
}
}
/*
* The following function is called from the Full Database Dump menu item, it retrieves the
* entire student DB and creates a CSV file with it. This module was created to aid in
* determining which students need to be purged from the database.
*/
private void createDatabaseDumpToolStripMenuItem_Click_1(object sender, EventArgs e)
{
try
{
SaveFileDialog saveFile = new SaveFileDialog();
saveFile.Filter = "txt files (*.txt)|*.txt|csv files (*.csv)|*.csv|xml files (*.xml)|*.xml";
saveFile.FilterIndex = 2;
saveFile.RestoreDirectory = true; //Should reset the directory when saving is finished.
//Maintaining the directory in other forms is still
//performed for reliability.
if (saveFile.ShowDialog() == DialogResult.OK)
{
using (StreamWriter outputfile = new StreamWriter(saveFile.FileName))
{
//first line creates the header line for later importing the data
outputfile.WriteLine("Last Name, First Name, Student ID");
Valid allStudents = new Valid();
List <string> fullDB = new List <string>(allStudents.StudentSearch("%", true));
//cycle through the retrieved list and write each line as plain text
for (int i = 0; i < fullDB.Count; i++)
{
string[] logLine = fullDB[i].Split(',');
outputfile.WriteLine(logLine[0] + "," + logLine[1] + "," + Utility.Decrypt(logLine[2], false)); //writing each list item to file
}
allStudents = null;
fullDB = null;
backedUp = true;
}
}
saveFile = null; //removes the save dialog from memory
}
catch
{
MessageBox.Show("Error exporting plain text log file.");
backedUp = false;
}
}