Gui problem, try #6

I've altered the code for the add and edit buttons to ensure only ids which consist of all digits are accepted and only dates of birth within certain limits are allowed (change the limits if you're not happy with them):

I've also changed something else which I thought could conceivably cause problems with the enabled buttons when leaving 'add' mode:

private void addStudentButton(object sender, EventArgs e)

{

viewStudRemove.Enabled = false;

if (addFirstNameTextBox.Text.Trim() == "" || addLastNameTextBox.Text.Trim() == "" || addStudentIdTextBox.Text.Trim() == "")

{

MessageBox.Show("All fields need to be completed", "Add student Error");

addFirstNameTextBox.Focus();

return;

}

if (this.addDateOfBirth.Value > DateTime.Today.AddYears(-15))

{

MessageBox.Show("Minimum age of a student is 15", "Add student Error");

addDateOfBirth.Focus();

return;

}

if (this.addDateOfBirth.Value <= DateTime.Today.AddYears(-30))

{

MessageBox.Show("Maximum age of a student is 29", "Add student Error");

addDateOfBirth.Focus();

return;

}

int id;

if (!int.TryParse(this.addStudentIdTextBox.Text, out id))

{

MessageBox.Show("ID field can contain only digits", "Add Student Error");

addStudentIdTextBox.Focus();

return;

}

foreach (Student s in students)

{

if (s.IdNumber == id)

{

MessageBox.Show("There's already a student with the same ID number", "Add Student Error");

addStudentIdTextBox.Focus();

return;

}

Student temp = new Student(this.addFirstNameTextBox.Text, this.addLastNameTextBox.Text, this.addDateOfBirth.Value, id); // no need to parse ID again

data.AddStudent(temp);

students.Add(temp);

currentIndex = students.Count - 1;

// display the student just added

DisplayStudent(students[currentIndex]);

//clear Add fields for next add

nextStudent.Enabled = false;

skipToLastStudent.Enabled = false;

if (students.Count == 1)

{

viewStudEdit.Enabled = true;

viewStudRemove.Enabled = true;

}

else if (students.Count >= 2) // 'belt and braces' amendment

{

skipToFirstStudent.Enabled = true;

previousStudent.Enabled = true;

}

addFirstNameTextBox.Text = "";

addLastNameTextBox.Text = "";

addStudentIdTextBox.Text = "";

addDateOfBirth.Value = new DateTime(1990, 1, 1);

viewStudRemove.Enabled = true;

}

private void editButton(object sender, EventArgs e)

{

//make it so the student can be changed

if (viewStudEdit.Text == "Edit")

{

viewStudEdit.Text = "Save";

viewDateOfBirth.Enabled = false;

viewAgeTextBox.Enabled = false;

skipToFirstStudent.Enabled = false;

previousStudent.Enabled = false;

nextStudent.Enabled = false;

skipToLastStudent.Enabled = false;

viewStudRemove.Enabled = false;

viewFirstNameTextBox.ReadOnly = false;

viewLastNameTextBox.ReadOnly = false;

viewStudentIdTextBox.ReadOnly = true; // dont allow ID to be changed

viewAgeTextBox.ReadOnly = false;

viewDateOfBirth.Enabled = true;

}

else

{

if (viewFirstNameTextBox.Text.Trim() == "" || viewLastNameTextBox.Text.Trim() == "")

{

MessageBox.Show("All fields need to be completed", "Edit student Error");

viewFirstNameTextBox.Focus();

return;

}

if (this.viewDateOfBirth.Value > DateTime.Today.AddYears(-15))

{

MessageBox.Show("Minimum age of a student is 15", "Edit student Error");

viewDateOfBirth.Focus();

return;

}

if (this.viewDateOfBirth.Value <= DateTime.Today.AddYears(-30))

{

MessageBox.Show("Maximum age of a student is 29", "Edit student Error");

viewDateOfBirth.Focus();

return;

}

DialogResult dr = MessageBox.Show("Are you sure want to save the changes?", "Edit Student Confirmation", MessageBoxButtons.YesNo);

if (dr == DialogResult.Yes)

{

students[currentIndex].FirstName = viewFirstNameTextBox.Text;

students[currentIndex].LastName = viewLastNameTextBox.Text;

students[currentIndex].DateOfBirth = viewDateOfBirth.Value;

viewAgeTextBox.Text = students[currentIndex].Age.ToString();

data.EditStudent(students[currentIndex]);

}

viewStudEdit.Text = "Edit";

if (currentIndex > 0)

skipToFirstStudent.Enabled = true;

previousStudent.Enabled = true;

if (currentIndex < students.Count - 1)

{

nextStudent.Enabled = true;

skipToLastStudent.Enabled = true;

}

viewStudRemove.Enabled = true;

viewFirstNameTextBox.ReadOnly = true;

viewLastNameTextBox.ReadOnly = true;

viewStudentIdTextBox.ReadOnly = true;

viewAgeTextBox.ReadOnly = true;

viewDateOfBirth.Enabled = false;

}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
Accepted answer
I've altered the code for the add and edit buttons to ensure only ids which consist of all digits are accepted and only dates of birth within certain limits are allowed (change the limits if you're not happy with them):

I've also changed something else which I thought could conceivably cause problems with the enabled buttons when leaving 'add' mode:

private void addStudentButton(object sender, EventArgs e)
{
viewStudRemove.Enabled = false;

if (addFirstNameTextBox.Text.Trim() == "" || addLastNameTextBox.Text.Trim() == "" || addStudentIdTextBox.Text.Trim() == "")
{
MessageBox.Show("All fields need to be completed", "Add student Error");
addFirstNameTextBox.Focus();
return;
}

if (this.addDateOfBirth.Value > DateTime.Today.AddYears(-15))
{
MessageBox.Show("Minimum age of a student is 15", "Add student Error");
addDateOfBirth.Focus();
return;
}

if (this.addDateOfBirth.Value <= DateTime.Today.AddYears(-30))
{
MessageBox.Show("Maximum age of a student is 29", "Add student Error");
addDateOfBirth.Focus();
return;
}

int id;
if (!int.TryParse(this.addStudentIdTextBox.Text, out id))
{
MessageBox.Show("ID field can contain only digits", "Add Student Error");
addStudentIdTextBox.Focus();
return;
}

foreach (Student s in students)
{
if (s.IdNumber == id)
{
MessageBox.Show("There's already a student with the same ID number", "Add Student Error");
addStudentIdTextBox.Focus();
return;
}
}

Student temp = new Student(this.addFirstNameTextBox.Text, this.addLastNameTextBox.Text, this.addDateOfBirth.Value, id); // no need to parse ID again
data.AddStudent(temp);
students.Add(temp);
currentIndex = students.Count - 1;
// display the student just added
DisplayStudent(students[currentIndex]);
//clear Add fields for next add
nextStudent.Enabled = false;
skipToLastStudent.Enabled = false;

if (students.Count == 1)
{
viewStudEdit.Enabled = true;
viewStudRemove.Enabled = true;
}
else if (students.Count >= 2) // 'belt and braces' amendment
{
skipToFirstStudent.Enabled = true;
previousStudent.Enabled = true;
}

addFirstNameTextBox.Text = "";
addLastNameTextBox.Text = "";
addStudentIdTextBox.Text = "";
addDateOfBirth.Value = new DateTime(1990, 1, 1);
viewStudRemove.Enabled = true;

}

private void editButton(object sender, EventArgs e)
{
//make it so the student can be changed
if (viewStudEdit.Text == "Edit")
{
viewStudEdit.Text = "Save";
viewDateOfBirth.Enabled = false;
viewAgeTextBox.Enabled = false;
skipToFirstStudent.Enabled = false;
previousStudent.Enabled = false;
nextStudent.Enabled = false;
skipToLastStudent.Enabled = false;
viewStudRemove.Enabled = false;
viewFirstNameTextBox.ReadOnly = false;
viewLastNameTextBox.ReadOnly = false;
viewStudentIdTextBox.ReadOnly = true; // dont allow ID to be changed
viewAgeTextBox.ReadOnly = false;
viewDateOfBirth.Enabled = true;
}
else
{
if (viewFirstNameTextBox.Text.Trim() == "" || viewLastNameTextBox.Text.Trim() == "")
{
MessageBox.Show("All fields need to be completed", "Edit student Error");
viewFirstNameTextBox.Focus();
return;
}

if (this.viewDateOfBirth.Value > DateTime.Today.AddYears(-15))
{
MessageBox.Show("Minimum age of a student is 15", "Edit student Error");
viewDateOfBirth.Focus();
return;
}

if (this.viewDateOfBirth.Value <= DateTime.Today.AddYears(-30))
{
MessageBox.Show("Maximum age of a student is 29", "Edit student Error");
viewDateOfBirth.Focus();
return;
}

DialogResult dr = MessageBox.Show("Are you sure want to save the changes?", "Edit Student Confirmation", MessageBoxButtons.YesNo);
if (dr == DialogResult.Yes)
{
students[currentIndex].FirstName = viewFirstNameTextBox.Text;
students[currentIndex].LastName = viewLastNameTextBox.Text;
students[currentIndex].DateOfBirth = viewDateOfBirth.Value;
viewAgeTextBox.Text = students[currentIndex].Age.ToString();
data.EditStudent(students[currentIndex]);
}
viewStudEdit.Text = "Edit";
if (currentIndex > 0)
skipToFirstStudent.Enabled = true;
previousStudent.Enabled = true;
if (currentIndex < students.Count - 1)
{
nextStudent.Enabled = true;
skipToLastStudent.Enabled = true;
}
viewStudRemove.Enabled = true;
viewFirstNameTextBox.ReadOnly = true;
viewLastNameTextBox.ReadOnly = true;
viewStudentIdTextBox.ReadOnly = true;
viewAgeTextBox.ReadOnly = true;
viewDateOfBirth.Enabled = false;
}

}
Prime b14y ago
Thank you!