// carries out the deletion of the question
// deletes from list of question objects first, then updates text file accordingly by rewriting all remaining
// question objects
private void deleteQuestionFromFile()
{
QuestionBank QtoDelete = null;
if (QuestionTextList.SelectedItem != null)
{
foreach (QuestionBank aQuestion in BoardAdmin.questions)
{
if (aQuestion.questiontext.ToString() == QuestionTextList.SelectedItem.ToString())
{
QtoDelete = aQuestion;
BoardAdmin.questions.Remove(QtoDelete);
break;
}
}
// writer for writing to file
StreamWriter aSW = new StreamWriter(File.Open("QuestionBank 2.csv", FileMode.Truncate));
// rewrites each question to the file - OVERWRITES
foreach (QuestionBank aQuestion in BoardAdmin.questions)
{
aSW.WriteLine(aQuestion.questiontext + "," + aQuestion.answer + "," + aQuestion.answer2 + "," + aQuestion.difficulty);
}
aSW.Close(); // close stream
// re-populate list box with the new contents of the question object list and hence the text file
QuestionTextList.Items.Clear();
populateListBox();
}
}
//This procedure carries out the task of adding the question to the file stored on the server.
//It checks that the input is valid and then it appends a new line containing the new question,
//in the correct format
private void addQuestionToFile()
{
if (QuestionTextBox.Text == "")
{
MessageBox.Show("Please enter the question text", "error");
}
if (Answer1Box.Text == "")
{
MessageBox.Show("Please enter the question Answer", "error");
}
if (DifficultyBox.Text == "")
{
MessageBox.Show("Please enter the Difficulty", "error");
}
int num; // stores the result of the conversion
bool isint = int.TryParse(DifficultyBox.Text, out num); // this checks that the difficulty is an integer
if (isint == true)
{
if (Convert.ToInt16(DifficultyBox.Text) > 3) // the difficulty level cannot be greater than 3
{
MessageBox.Show("the difficulty cannot exceed 3", "error");
}
else
{
if (QuestionTextBox.Text != "" && Answer1Box.Text != "")
{
QuestionBank newQuestion = new QuestionBank(QuestionTextBox.Text, Answer1Box.Text, Answer2Box.Text, Convert.ToInt16(DifficultyBox.Text));
BoardAdmin.questions.Add(newQuestion);
File.AppendAllText("QuestionBank 2.csv", Environment.NewLine + newQuestion.questiontext + "," + newQuestion.answer + "," + newQuestion.answer2 + "," + newQuestion.difficulty);
MessageBox.Show("Question added successfully!", "Successful!");
}
}
}
}
// when the edit button is clicked
private void EditQuestionsButton_Click(object sender, EventArgs e)
{
//checks that there is a selection
if (QuestionTextList.SelectedItem != null)
{
// validates to ensure all appropiate data is available
if (QuestionTextBox.Text == "" || Answer1Box.Text == "")
{
MessageBox.Show("fields are empty", "error");
}
else
{
int num; // stores result of conversion
bool isint = int.TryParse(DifficultyBox.Text, out num); // checks for integer values
if (isint == true)
{
if (num > 3)
{
MessageBox.Show("the difficulty cannot exceed 3", "error");
}
else
{
QuestionBank QtoEdit = null;
foreach (QuestionBank aQuestion in BoardAdmin.questions)
{
QuestionTextList.SelectedItem = aQuestion;
if (aQuestion.questiontext.ToString() == QuestionTextList.SelectedItem.ToString())
{
QtoEdit = aQuestion;
BoardAdmin.questions.Remove(QtoEdit);
break;
}
}
QtoEdit.questiontext = QuestionTextBox.Text;
QtoEdit.answer = Answer1Box.Text;
QtoEdit.answer2 = Answer2Box.Text;
QtoEdit.difficulty = Convert.ToInt16(DifficultyBox.Text);
BoardAdmin.questions.Add(QtoEdit);
File.WriteAllText("QuestionBank 2.csv", string.Empty);
StreamWriter aSW = new StreamWriter(File.Open("QuestionBank 2.csv", FileMode.Open));
foreach (QuestionBank aQuestion in BoardAdmin.questions)
{
// re writes each question as a line in the text file
aSW.WriteLine(aQuestion.questiontext + "," + aQuestion.answer + "," + aQuestion.answer2 + "," + aQuestion.difficulty);
}
aSW.Close(); // closes the stream
// the following takes the text from the file and removes all blank lines after the content to ensure no errors occur
// when reading in from the file on another process
string temptext = File.ReadAllText("QuestionBank 2.csv");
temptext = temptext.Trim();
File.WriteAllText("QuestionBank 2.csv", temptext); // overwrites
QuestionTextList.Items.Clear();
populateListBox();
MessageBox.Show("Question edited successfully!", "Successful!");
}
}
else
{
MessageBox.Show("The difficulty must be a number", "error");
}
}
}
}
