private void btnCalculate_Click(object sender, EventArgs e)
{
//declare output variables
double assignmentMark;
double workshopMark;
double participationMark;
double finalMark;
//validate data entered by user
try
{
//check validity
// if you don't have a valid value from user, don't execute the following blocks
if (IsValidData())
{
//increment number of student every time a button is clicked
nrStudents++;
//get inputs from the user
assignmentMark = Convert.ToDouble(txtAssignments.Text);
workshopMark = Convert.ToDouble(txtWorkshop.Text);
participationMark = Convert.ToDouble(txtParticipation.Text);
// create object of new student
Student nextStudent = new Student(assignmentMark, workshopMark, participationMark);
nextStudent.Name = txtStudentName.Text;
//calculate new class average by using student object property FinalMark
totalMarks += nextStudent.FinalMark;
averageMark = totalMarks / nrStudents;
averageMark = Math.Round(averageMark)/100;
//calculate how many students got over 50% and passed and how many students failed.
//Display results in textboxes
if (nextStudent.FinalMark >= 50)
{
studentsPassed++;
txtPassed.Text = studentsPassed.ToString();
}
else
{
studentsFailed++;
txtFailed.Text = studentsFailed.ToString();
}
students.Add(nextStudent); // add the new student to the list
//display student info in the listbox
//listbox does not support newlines, so have to split the resulting string into several
//since the string deliminator is not one character but several, use Regex.Split
ltbStudentInfo.Items.Add(nrStudents + ". "); //this displays number of thestudent as you enter them
foreach (string s in Regex.Split(nextStudent.ToString(), "\n"))
ltbStudentInfo.Items.Add(s);
//display final mark and grade
finalMark = nextStudent.FinalMark*0.01;// get finalMark as fraction so it can be displayed as a percent
txtStudentMark.Text = finalMark.ToString("P0");
txtStudentGrade.Text = nextStudent.LetterGrade;
txtAverageMark.Text = averageMark.ToString("P0");
}
}
//display if an exception that has not been anticipated is thrown
catch (Exception ex)
{
MessageBox.Show(ex.Message + "\n\n" + //get description of error
ex.GetType().ToString() + "\n" + //get the type of class that was used to create the exception object
ex.StackTrace, "Exception"); //stack trace is a list of methods called before exception occurred
}
}
private void btnCalculate_Click(object sender, EventArgs e)
{
// declare input variables
double assignmentMark;
double workshopMark;
double participationMark;
string studentName;
//declare output variables
double finalMark;
string finalGrade;
string listboxOutput;
//validate data entered by user
try
{
//check validity
// if you don't have a valid value from user, don't execute the following blocks
if (IsValidData())
{
//increment number of student every time a button is clicked
numberOfStudents++;
//give an error message if user tries to enter more students than max number allowed
if (numberOfStudents > maxNumberOfStudents)
{
MessageBox.Show("You cannot enter more than " + maxNumberOfStudents + " students.");
btnCalculate.Enabled = false; //this will disable the calculate button so that user cannot enter more data
return;
}
//declare arrays to store, an array of student names, marks and letter grades
// added one to index to accomodate the fact that there is no student zero, we start at student one
//added another one to ensure there is no exception warning for reaching outside of index bounds
//there will be an error message that will disable the calculate button if student count reaches maximum
string[] studentNames = new string[maxNumberOfStudents+1+1];
double[] studentMarks = new double[maxNumberOfStudents+1+1];
string[] studentGrades = new string[maxNumberOfStudents+1+1];
//get input from user
studentName = txtStudentName.Text;
//add student name to the studentNames array
studentNames[numberOfStudents] = studentName;
Student nextStudent = new Student(); // create object of new student
nextStudent.Name = txtStudentName.Text;
//call calculate method that will determine all marks and grades
calculateGradeAndMarks(out assignmentMark, out workshopMark, out participationMark,
out finalMark, out finalGrade);
//store marks and grades in arrays
studentMarks[numberOfStudents] = finalMark*100; //calculated value is a fraction so need to multiply by 100
studentGrades[numberOfStudents] = finalGrade;
nextStudent.Mark = finalMark * 100;
nextStudent.Grade = finalGrade;
//calculate how many students got over 50% and passed and how many students failed.
//Display results in textboxes
if (finalMark >= 0.5)
{
studentsPassed++;
txtPassed.Text = studentsPassed.ToString();
}
else
{
studentsFailed++;
txtFailed.Text = studentsFailed.ToString();
}
//add results to listbox describing history so far
listboxOutput = "Student " + numberOfStudents + ", " + studentNames[numberOfStudents] + ", Final Mark: "
+ studentMarks[numberOfStudents] + "%, Final Grade: "
+ studentGrades[numberOfStudents];
ltbStudentInfo.Items.Add(listboxOutput);
}
}
//display if an exception that has not been anticipated is thrown
catch (Exception ex)
{
MessageBox.Show(ex.Message + "\n\n" + //get description of error
ex.GetType().ToString() + "\n" + //get the type of class that was used to create the exception object
ex.StackTrace, "Exception"); //stack trace is a list of methods called before exception occurred
}
}
