Help with GUI#2

Question

Vulpes remember the GUI we were working on ( more like you were wokring on it lol....)
I took it to teacher today and he broke it, the students are kept in array and when you remove student and click previous student button it will crash, because the array has no value in it.
For some reason when you click next student, the previous and skip buttons are disabled.
Also I was working on it and renamed buttons the way you told me, I also renamed the text boxes to more appropriate names. I renamed the foofoo to currentDateTime and now it wont compile properly, I also gotta rename snark to something that is appropriate pretty much I gotta rename all the non-sense identifi

Vulpes · 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 { 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 { 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 // 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 b · Answer

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 b · Answer

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 b · Answer

Vulpes?

Prime b · Answer

someone?