Help with GUI#2

I'm not surprised it blew up when your teacher tried it as you've failed to make a number of the changes that I posted in the previous thread!

With all the names having changed, it's taken me a long time to get it working again, so I'm not best pleased, but this is how Form1 should now look (changes are marked with a double asterisk comment):

namespace Student_Viewer

{

public partial class Form1 : Form

{

private PersistantData data = new PersistantData();

private int corn = 0;

private List ready;

public Form1()

{

InitializeComponent();

ready = new List(data.RetreiveStudents());

// remove nulls

for (int index = ready.Count - 1; index >= 0; --index)

{

if (ready[index] == null) ready.RemoveAt(index);

}

if (ready.Count > 0)

DisplayStudent(ready[0]);

else

{

DisplayStudent(null);

viewStudEdit.Enabled = false;

viewStudRemove.Enabled = false;

}

skipToFirstStudent.Enabled = false;

previousStudent.Enabled = false;

if (ready.Count < 2)

{

nextStudent.Enabled = false;

skipToLastStudent.Enabled = false;

}

private void DisplayStudent(Student stu)

{

//shows a student

if (stu != null)

{

viewFirstNameTextBox.Text = stu.FirstName;

viewLastNameTextBox.Text = stu.LastName;

viewDateOfBirth.Value = stu.DateOfBirth;

viewAgeTextBox.Text = stu.Age.ToString();

viewStudentIdTextBox.Text = stu.IdNumber.ToString();

}

else

{

viewFirstNameTextBox.Text = "";

viewLastNameTextBox.Text = "";

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

viewAgeTextBox.Text = "";

viewStudentIdTextBox.Text = "";

}

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"); // ** error mis-spelt

addFirstNameTextBox.Focus();

return;

}

int id = Convert.ToInt32(this.addStudentIdTextBox.Text);

foreach (Student s in ready)

{

if (s.IdNumber == id)

{

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

addStudentIdTextBox.Focus();

return;

}

//adds student to storage

Student temp = new Student(this.addFirstNameTextBox.Text, this.addLastNameTextBox.Text, this.addDateOfBirth.Value, Convert.ToInt32(this.addStudentIdTextBox.Text));

data.AddStudent(temp);

ready.Add(temp);

corn = ready.Count - 1;

// display the student just added

DisplayStudent(ready[corn]);

//clear Add fields for next add

nextStudent.Enabled = false;

skipToLastStudent.Enabled = false;

if (ready.Count == 1)

{

viewStudEdit.Enabled = true;

viewStudRemove.Enabled = true;

}

addFirstNameTextBox.Text = "";

addLastNameTextBox.Text = "";

addStudentIdTextBox.Text = "";

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

viewStudRemove.Enabled = true;

}

private void renameButton(object sender, EventArgs e)

{

//remove this student

DialogResult dr = MessageBox.Show("Are you sure you want to remove this student?", "Remove Student Confirmation", MessageBoxButtons.YesNo);

if (dr == DialogResult.No) return; // ** inserted this line

// if (ready.Count == 0) return; // ** removed this line

data.RemoveStudent(ready[corn]);

ready.RemoveAt(corn);

//display the student before the one removed if there is one, otherwise display first student

if (corn > 0)

--corn;

else

corn = 0;

if (ready.Count > 0)

DisplayStudent(ready[corn]);

else

{

DisplayStudent(null);

viewStudEdit.Enabled = false;

viewStudRemove.Enabled = false;

}

if (corn == 0)

{

skipToFirstStudent.Enabled = false;

previousStudent.Enabled = false;

}

if (ready.Count < 2)

{

nextStudent.Enabled = false;

skipToLastStudent.Enabled = false;

}

private void nextButton(object sender, EventArgs e)

{

//shows the next student

//if (ready.Count == 0) return; // ** removed

//if (corn < ready.Count - 1) // ** removed

// DisplayStudent(ready[++corn]); // ** removed

// ** added all remaining lines

DisplayStudent(ready[++corn]);

if (corn == 1)

{

skipToFirstStudent.Enabled = true;

previousStudent.Enabled = true;

}

if (corn == ready.Count - 1)

{

nextStudent.Enabled = false;

skipToLastStudent.Enabled = false;

}

private void previousButton(object sender, EventArgs e)

{

//shows the prev student

DisplayStudent(ready[--corn]);

if (corn == 0) // ** changed from corn == 1

{

skipToFirstStudent.Enabled = false;

previousStudent.Enabled = false;

}

if (corn == ready.Count - 2)

{

nextStudent.Enabled = true;

skipToLastStudent.Enabled = true;

}

private void skipBackButton(object sender, EventArgs e)

{

// shows the first student

// if (ready.Count == 0) return; // ** removed

if (corn == 0) return; // ** added

corn = 0;

DisplayStudent(ready[corn]);

skipToFirstStudent.Enabled = false; // Disabled skip student when there's no students

previousStudent.Enabled = false; // Disables next student when there's no students

nextStudent.Enabled = true;

skipToLastStudent.Enabled = true;

}

private void skipForwardButton(object sender, EventArgs e)

{

// shows the last student

// if (ready.Count == 0) return; // ** removed

if (corn == ready.Count - 1) return; // ** added

corn = ready.Count - 1;

DisplayStudent(ready[corn]);

nextStudent.Enabled = false; // Disabled next student when there's no students

skipToLastStudent.Enabled = false; // Disabled skip student when there's no students

skipToFirstStudent.Enabled = true;

previousStudent.Enabled = true;

}

private void editButton(object sender, EventArgs e)

{

//make it so the student can be changed

if (viewStudEdit.Text == "Edit")

{

viewStudEdit.Text = "Save";

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

{

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

if (dr == DialogResult.Yes)

{

ready[corn].FirstName = viewFirstNameTextBox.Text;

ready[corn].LastName = viewLastNameTextBox.Text;

ready[corn].DateOfBirth = viewDateOfBirth.Value;

data.EditStudent(ready[corn]);

}

viewStudEdit.Text = "Edit";

skipToFirstStudent.Enabled = true;

previousStudent.Enabled = true;

nextStudent.Enabled = true;

skipToLastStudent.Enabled = true;

viewStudRemove.Enabled = true;

viewFirstNameTextBox.ReadOnly = true;

viewLastNameTextBox.ReadOnly = true;

viewStudentIdTextBox.ReadOnly = true;

viewAgeTextBox.ReadOnly = true;

viewDateOfBirth.Enabled = false;

}

}

Also you seem to have added a ValueChanged eventhandler to the addDateOfBirth DateTimePicker but then deleted the handler

which was called addDateOfBirth_ValueChanged. Consequently, it will no longer compile. To fix this, you'll have to edit the InitializeComponent() method in Form1.Designer.cs manually. I've marked the line which needs to be deleted below:

// addDateOfBirth

this.addDateOfBirth.Format = System.Windows.Forms.DateTimePickerFormat.Short;

this.addDateOfBirth.Location = new System.Drawing.Point(110, 96);

this.addDateOfBirth.MaxDate = new System.DateTime(2099, 12, 31, 0, 0, 0, 0);

this.addDateOfBirth.MinDate = new System.DateTime(1930, 1, 1, 0, 0, 0, 0);

this.addDateOfBirth.Name = "addDateOfBirth";

this.addDateOfBirth.Size = new System.Drawing.Size(200, 20);

this.addDateOfBirth.TabIndex = 3;

this.addDateOfBirth.Value = new System.DateTime(1990, 1, 1, 0, 0, 0, 0);

//this.addDateOfBirth.ValueChanged += new System.EventHandler(this.addDateOfBirth_ValueChanged); //** removed this line

When you've made these changes just rebuild and run.

I can't promise it's now bug-free but it's a lot better than it was.

5 Replies

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

Vulpes14y ago
Accepted answer
I'm not surprised it blew up when your teacher tried it as you've failed to make a number of the changes that I posted in the previous thread!

With all the names having changed, it's taken me a long time to get it working again, so I'm not best pleased, but this is how Form1 should now look (changes are marked with a double asterisk comment):

namespace Student_Viewer
{
public partial class Form1 : Form
{
private PersistantData data = new PersistantData();
private int corn = 0;
private List ready;

public Form1()
{
InitializeComponent();
ready = new List(data.RetreiveStudents());
// remove nulls
for (int index = ready.Count - 1; index >= 0; --index)
{
if (ready[index] == null) ready.RemoveAt(index);
}

if (ready.Count > 0)
DisplayStudent(ready[0]);
else
{
DisplayStudent(null);
viewStudEdit.Enabled = false;
viewStudRemove.Enabled = false;
}
skipToFirstStudent.Enabled = false;
previousStudent.Enabled = false;

if (ready.Count < 2)
{
nextStudent.Enabled = false;
skipToLastStudent.Enabled = false;
}
}

private void DisplayStudent(Student stu)
{
//shows a student
if (stu != null)
{
viewFirstNameTextBox.Text = stu.FirstName;
viewLastNameTextBox.Text = stu.LastName;
viewDateOfBirth.Value = stu.DateOfBirth;
viewAgeTextBox.Text = stu.Age.ToString();
viewStudentIdTextBox.Text = stu.IdNumber.ToString();
}
else
{
viewFirstNameTextBox.Text = "";
viewLastNameTextBox.Text = "";
viewDateOfBirth.Value = new DateTime(1990, 1, 1);
viewAgeTextBox.Text = "";
viewStudentIdTextBox.Text = "";
}
}

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"); // ** error mis-spelt
addFirstNameTextBox.Focus();
return;
}

int id = Convert.ToInt32(this.addStudentIdTextBox.Text);

foreach (Student s in ready)
{
if (s.IdNumber == id)
{
MessageBox.Show("There's already a student with the same ID number", "Add Student Error");
addStudentIdTextBox.Focus();
return;
}
}
//adds student to storage
Student temp = new Student(this.addFirstNameTextBox.Text, this.addLastNameTextBox.Text, this.addDateOfBirth.Value, Convert.ToInt32(this.addStudentIdTextBox.Text));
data.AddStudent(temp);
ready.Add(temp);
corn = ready.Count - 1;
// display the student just added
DisplayStudent(ready[corn]);
//clear Add fields for next add
nextStudent.Enabled = false;
skipToLastStudent.Enabled = false;

if (ready.Count == 1)
{
viewStudEdit.Enabled = true;
viewStudRemove.Enabled = true;
}

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

}

private void renameButton(object sender, EventArgs e)
{
//remove this student
DialogResult dr = MessageBox.Show("Are you sure you want to remove this student?", "Remove Student Confirmation", MessageBoxButtons.YesNo);
if (dr == DialogResult.No) return; // ** inserted this line

// if (ready.Count == 0) return; // ** removed this line

data.RemoveStudent(ready[corn]);
ready.RemoveAt(corn);
//display the student before the one removed if there is one, otherwise display first student
if (corn > 0)
--corn;
else
corn = 0;

if (ready.Count > 0)
DisplayStudent(ready[corn]);
else
{
DisplayStudent(null);
viewStudEdit.Enabled = false;
viewStudRemove.Enabled = false;
}
if (corn == 0)
{
skipToFirstStudent.Enabled = false;
previousStudent.Enabled = false;
}
if (ready.Count < 2)
{
nextStudent.Enabled = false;
skipToLastStudent.Enabled = false;
}
}

private void nextButton(object sender, EventArgs e)
{
//shows the next student

//if (ready.Count == 0) return; // ** removed
//if (corn < ready.Count - 1) // ** removed
// DisplayStudent(ready[++corn]); // ** removed

// ** added all remaining lines
DisplayStudent(ready[++corn]);

if (corn == 1)
{
skipToFirstStudent.Enabled = true;
previousStudent.Enabled = true;
}

if (corn == ready.Count - 1)
{
nextStudent.Enabled = false;
skipToLastStudent.Enabled = false;
}

}

private void previousButton(object sender, EventArgs e)
{
//shows the prev student
DisplayStudent(ready[--corn]);
if (corn == 0) // ** changed from corn == 1
{
skipToFirstStudent.Enabled = false;
previousStudent.Enabled = false;
}
if (corn == ready.Count - 2)
{
nextStudent.Enabled = true;
skipToLastStudent.Enabled = true;
}

}

private void skipBackButton(object sender, EventArgs e)
{
// shows the first student
// if (ready.Count == 0) return; // ** removed
if (corn == 0) return; // ** added
corn = 0;
DisplayStudent(ready[corn]);
skipToFirstStudent.Enabled = false; // Disabled skip student when there's no students
previousStudent.Enabled = false; // Disables next student when there's no students
nextStudent.Enabled = true;
skipToLastStudent.Enabled = true;
}

private void skipForwardButton(object sender, EventArgs e)
{
// shows the last student
// if (ready.Count == 0) return; // ** removed
if (corn == ready.Count - 1) return; // ** added
corn = ready.Count - 1;
DisplayStudent(ready[corn]);
nextStudent.Enabled = false; // Disabled next student when there's no students
skipToLastStudent.Enabled = false; // Disabled skip student when there's no students
skipToFirstStudent.Enabled = true;
previousStudent.Enabled = true;
}

private void editButton(object sender, EventArgs e)
{
//make it so the student can be changed
if (viewStudEdit.Text == "Edit")
{
viewStudEdit.Text = "Save";
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
{
DialogResult dr = MessageBox.Show("Are you sure want to save the changes?", "Edit Student Confirmation", MessageBoxButtons.YesNo);
if (dr == DialogResult.Yes)
{
ready[corn].FirstName = viewFirstNameTextBox.Text;
ready[corn].LastName = viewLastNameTextBox.Text;
ready[corn].DateOfBirth = viewDateOfBirth.Value;
data.EditStudent(ready[corn]);
}
viewStudEdit.Text = "Edit";
skipToFirstStudent.Enabled = true;
previousStudent.Enabled = true;
nextStudent.Enabled = true;
skipToLastStudent.Enabled = true;
viewStudRemove.Enabled = true;
viewFirstNameTextBox.ReadOnly = true;
viewLastNameTextBox.ReadOnly = true;
viewStudentIdTextBox.ReadOnly = true;
viewAgeTextBox.ReadOnly = true;
viewDateOfBirth.Enabled = false;
}

}

}
}

Also you seem to have added a ValueChanged eventhandler to the addDateOfBirth DateTimePicker but then deleted the handler
which was called addDateOfBirth_ValueChanged. Consequently, it will no longer compile. To fix this, you'll have to edit the InitializeComponent() method in Form1.Designer.cs manually. I've marked the line which needs to be deleted below:

// addDateOfBirth
//
this.addDateOfBirth.Format = System.Windows.Forms.DateTimePickerFormat.Short;
this.addDateOfBirth.Location = new System.Drawing.Point(110, 96);
this.addDateOfBirth.MaxDate = new System.DateTime(2099, 12, 31, 0, 0, 0, 0);
this.addDateOfBirth.MinDate = new System.DateTime(1930, 1, 1, 0, 0, 0, 0);
this.addDateOfBirth.Name = "addDateOfBirth";
this.addDateOfBirth.Size = new System.Drawing.Size(200, 20);
this.addDateOfBirth.TabIndex = 3;
this.addDateOfBirth.Value = new System.DateTime(1990, 1, 1, 0, 0, 0, 0);
//this.addDateOfBirth.ValueChanged += new System.EventHandler(this.addDateOfBirth_ValueChanged); //** removed this line

When you've made these changes just rebuild and run.

I can't promise it's now bug-free but it's a lot better than it was.
Prime b14y ago
heh.... spent about 7 minutes to get inside of the form designer. What I did is just double-clicked the date of birth selector so it will create new even handle, then i right click and i clicked something and it opened like new window that showed me the location where its used, and of them was Form1.Designer.cs!!!!
Prime b14y ago
Oh god Vulpes thank you vm, i pretty failed at copying your work... ty! now I have to go over the old form and new form and compare and understand whats going on there
Prime b14y ago
Vulpes?
Prime b14y ago
someone?