Creating a previous list item, Next list item, Display the current record and get an button enable

Question

Hello,

im new to visual basic 2005. im having problems Creating a previous list item, Next list item, Display the current record and get an button enable.

can anyone out there help

Here is the code

' Chapter.08 - Solution to Hands-on Project 1

'

' Modified from:

'

' Programming With Visual Basic .NET

' An Object-Oriented Approach - Second Edition

Option Explicit On

Option Strict On

Imports System.Convert

Public Class frmMain

' Create the generic EmployeeList

Private EmployeeList As New List(Of Employee)

' Initalize the index to indicate that there are no employees

' in the list.

Dim CurrentIndex As Integer = -1

' Keep track of max employee ID

Dim MaxEmployeeID As Integer = 0

' String to store messages

Dim MsgStr As String

' Display the record count when the form is initialized.

Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

End Sub

' Save a new employee to the list.

Private Sub btnSaveNew_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSaveNew.Click

' Instantiate employee object

Dim EmpCurrent As New Employee

 

' If all are valid save else display error

If IsAllValid() Then

' Increment the Max Employee indicating the latest number added.

MaxEmployeeID = MaxEmployeeID + 1

' Assign an EmployeeID automatically.

EmpCurrent.EmployeeID = MaxEmployeeID

' Populate the remaining Employee object data.

EmpCurrent.EmployeeType = txtEmployeeType.Text

EmpCurrent.EmployeeName = txtEmployeeName.Text

EmpCurrent.EmployeeAddress = txtEmployeeAddress.Text

EmpCurrent.EmployeeSSN = txtEmployeeSSN.Text

' Add the Employee to the generic list.

EmployeeList.Add(EmpCurrent)

' Display the employee ID to text box.

txtEmployeeID.Text = EmpCurrent.EmployeeID.ToString

' Add an employee to the listbox on form

lisEmployees.Items.Add(EmpCurrent.EmployeeID.ToString & EmpCurrent.EmployeeName.ToString)

' Clear the contents of the text boxes.

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

Else

MsgBox(MsgStr)

End If

' Write the next available Employee ID to the ID text box

txtEmployeeID.Text = (MaxEmployeeID + 1).ToString

' Display the number of employees in the list to the count text box.

txtRecordCount.Text = (MaxEmployeeID + CurrentIndex).ToString

End Sub

Private Function IsAllValid() As Boolean

' Assume all valid input

Dim AllValid As Boolean = True

MsgStr = "Please enter valid: " & ControlChars.CrLf

' Is Employee Type valid

If Not (txtEmployeeType.Text = "Manager" Or txtEmployeeType.Text = "Staff") Then

AllValid = False

MsgStr = MsgStr & "Employee type ('Manager' OR 'Staff')" & ControlChars.CrLf

End If

' Is Employee Name valid

If txtEmployeeName.Text = "" Then

AllValid = False

MsgStr = MsgStr & "Employee Name can't be empty" & ControlChars.CrLf

End If

' Is Employee Address valid

If txtEmployeeAddress.Text = "" Then

AllValid = False

MsgStr = MsgStr & "Employee Address can't be empty" & ControlChars.CrLf

End If

' Is Employee SSN valid

If Not IsValidSSN(txtEmployeeSSN.Text) Then

AllValid = False

MsgStr = MsgStr & "Employee SSN ('###-##-####')" & ControlChars.CrLf

End If

' Return result

Return AllValid

End Function

 

' Save the changes contained in the text boxes to the list.

Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click

Dim EmpCurrent As New Employee

' If all are valid save else display error

If IsAllValid() Then

' Increment the Max Employee indicating the latest number added.

MaxEmployeeID = MaxEmployeeID + 1

' Assign an EmployeeID automatically.

EmpCurrent.EmployeeID = MaxEmployeeID

' Populate the remaining Employee object data.

EmpCurrent.EmployeeType = txtEmployeeType.Text

EmpCurrent.EmployeeName = txtEmployeeName.Text

EmpCurrent.EmployeeAddress = txtEmployeeAddress.Text

EmpCurrent.EmployeeSSN = txtEmployeeSSN.Text

' Add the Employee to the generic list.

EmployeeList.Add(EmpCurrent)

 

Else

MsgBox(MsgStr)

End If

End Sub

' Delete the current list item.

Private Sub btnDeleteCurrent_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDeleteCurrent.Click

Dim EmpCurrent As Employee

If CurrentIndex > -1 Then

' Remove Employee from list

Try

lisEmployees.Items.Remove(EmpCurrent.EmployeeID.ToString & EmpCurrent.EmployeeName.ToString)

Catch ex As ArgumentOutOfRangeException

MessageBox.Show("Employee Not Found")

End Try

' Write Employee count to text box

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

Else

MsgBox("There are no records to delete.")

End If

End Sub

' Display the previous list item.

Private Sub btnPrevious_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPrevious.Click

End Sub

' Display the next list item.

Private Sub btnNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNext.Click

End Sub

' Exit the application.

Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click

Me.Close()

End Sub

Private Sub btnClearForm_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClearForm.Click

' Clear the contents of the text boxes.

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

' Write the next available Employee ID to the ID text box

txtEmployeeID.Text = (MaxEmployeeID + 1).ToString

End Sub

' Display the current record.

Private Sub DisplayCurrentRecord()

End Sub

Private Sub ClearFields()

' Clear the contents of the text boxes.

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

End Sub

Private Sub btnAddNew_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddNew.Click

grpAdd.Enabled = True

grpEmpData.Enabled = True

btnAddNew.Enabled = False

btnViewExisting.Enabled = False

' Clear the contents of the text boxes.

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

' Write the next available Employee ID to the ID text box

txtEmployeeID.Text = (MaxEmployeeID + 1).ToString

End Sub

Private Sub btnViewExisting_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnViewExisting.Click

grpEditView.Enabled = True

btnAddNew.Enabled = False

btnViewExisting.Enabled = False

btnGetEmployee.Enabled = False

' Clear the contents of the text boxes.

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

End Sub

Private Sub btnExitAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExitAdd.Click

grpAdd.Enabled = False

grpEmpData.Enabled = False

btnAddNew.Enabled = True

btnViewExisting.Enabled = True

' Clear the contents of the text boxes.

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

End Sub

Private Sub btnExitView_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExitView.Click

grpEditView.Enabled = False

grpEmpData.Enabled = False

btnAddNew.Enabled = True

btnViewExisting.Enabled = True

' Clear the contents of the text boxes.

ClearFields()

txtEmployeeID.Text = ""

txtEmployeeType.Text = ""

txtEmployeeName.Text = ""

txtEmployeeAddress.Text = ""

txtEmployeeSSN.Text = ""

End Sub

Private Sub btnGetEmployee_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGetEmployee.Click

Dim EmpCurrent As New Employee

Try

' Get employee selected in list box

CurrentIndex = lisEmployees.SelectedIndex

If CurrentIndex > -1 Then

Try

lisEmployees.Items.Add(EmpCurrent.EmployeeID)

Catch ex As Exception

MessageBox.Show("Employee is Found")

End Try

Else

End If

btnPrevious.Enabled = True

btnNext.Enabled = True

btnUpdate.Enabled = True

btnDeleteCurrent.Enabled = True

grpEmpData.Enabled = True

Catch ex As Exception

MsgBox("No Employees exist")

End Try

End Sub

' Function to check for a valid SSN

Private Function IsValidSSN(ByVal arg As String) As Boolean

Dim Count As Integer

Dim CurrentChar As Integer

If arg.Length = 11 Then

' Check all eleven chars in string

For Count = 0 To 10

CurrentChar = Asc(arg.Substring(Count, 1))

Select Case Count

' Check for numeric ascii values

Case 0, 1, 2, 4, 5, 7, 8, 9, 10

If Not (CurrentChar >= 48 And CurrentChar <= 57) Then

Return False

End If

' Check for a dash ascii value

Case 3, 6

If Not (CurrentChar = 45) Then

Return False

End If

End Select

Next

Else

Return False

End If

Return True

End Function

Private Sub lisEmployees_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lisEmployees.Click

' Check to see if btnGetEmployee should be enabled

End Sub

End Class

Answer 1

Hi,

Would you please list the problems / exception messages you're experiencing? It would be great if you can share your whole project since the form code above is not complete to easily reproducing your problems.

Best regards,