Duplicating items on listbox - vb.net

Question

I have a program that records homework in a list box, and sorts it by the date it is due. However, when I try to sort the data by date, it does so, but duplicates each item in the list box. This can be rectified by closing the program and opening it again, but this is very inconvenient. Is there any way to fix this?
Here is the code for the two
frmSplashScreen:
Imports System.IO
Public Class frmSplashscreen
Dim dates() As Date = {}
Dim temparray() As String = {}
Dim temparray2() As String = {}
Dim Path As String = Application.StartupPath
Dim newuser As Boolean = False
Dim sorted As Boolean = False
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
If lstDate.Items.Contains("No assignments yet!") Then
lstDate.Items.Clear()
End If
frmAdd.Show()
Me.Hide()
End Sub
Private Sub Me_mouseenter(sender As Object, e As EventArgs) Handles Me.MouseEnter
If sorted = False And lstDate.Items.Contains("No assignments yet!") = False Then
SortByDate()
End If
End Sub
Private Sub frmSplashscreen_Load(sender As Object, e As EventArgs) Handles MyBase.Load
If File.Exists(Path & "Assignments.crw") = False Then
newuser = True
lstDate.Items.Add("No assignments yet!")
Else
FileOpen(1, Path & "Assignments.crw", OpenMode.Input)
While Not EOF(1)
Dim output As String = LineInput(1)
lstAssignments.Items.Add(Mid(output, InStr(output, "-") + 1, InStr(output, "_") - (InStr(output, "-") + 1)))
lstAN.Items.Add(Mid(output, InStr(output, "_") + 1, output.Length))
lstDate.Items.Add(Mid(output, 1, InStr(output, "-") - 1))
Array.Resize(temparray, temparray.Length + 1)
temparray(temparray.Length - 1) = output
End While
End If
FileClose(1)
If lstDate.Items.Contains("No assignments yet!") = False Then
SortByDate()
End If
End Sub
Private Sub SortByDate()
For Each x In lstDate.Items
MsgBox(x)
Array.Resize(dates, dates.Length + 1)
dates(dates.Length - 1) = x
Next
Array.Sort(dates)
' Sort dates.
temparray2 = {}
' Empty temparray2 for resizing
Dim counter As Integer = 0
' Declare counter
For Each x In dates
' Looping through dates...
Dim result As Integer
' ...Declare result.
For Each y In temparray
' Nestled for loop to check each result against one another. This time looping through temparray.
result = InStr(y, x)
' Search for x (The date) in y (the line of the file)
If result <> 0 Then
' If it is found...
Array.Resize(temparray2, temparray2.Length + 1)
counter = counter + 1
temparray2(counter - 1) = y
' Add y to the array temparray2 in chronological order.
End If
Next
Next
Dim num As Integer = 0
' Declare num
lstAN.Items.Clear()
lstAssignments.Items.Clear()
lstDate.Items.Clear()
temparray = {}
lstAN.Items.Clear()
lstAssignments.Items.Clear()
lstDate.Items.Clear()
For Each x In temparray2
Array.Resize(temparray, temparray2.Length)
temparray(num) = x
lstAssignments.Items.Add(Mid(x, InStr(x, "-") + 1, InStr(x, "_") - (InStr(x, "-") + 1)))
lstAN.Items.Add(Mid(x, InStr(x, "_") + 1, x.Length))
lstDate.Items.Add(Mid(x, 1, InStr(x, "-") - 1))
num += 1
Next
' Loop through temparray2 making temparray the exact same and adding the array to the listbox.
sorted = True
End Sub
Private Sub SortMyLife()
If File.Exists(Path & "Assignments.crw") = False Then
newuser = True
lstDate.Items.Add("No assignments yet!")
Else
FileOpen(1, Path & "Assignments.crw", OpenMode.Input)
While Not EOF(1)
Dim output As String = LineInput(1)
lstAssignments.Items.Add(Mid(output, InStr(output, "-") + 1, InStr(output, "_") - (InStr(output, "-") + 1)))
lstAN.Items.Add(Mid(output, InStr(output, "_") + 1, output.Length))
lstDate.Items.Add(Mid(output, 1, InStr(output, "-") - 1))
Array.Resize(temparray, temparray.Length + 1)
temparray(temparray.Length - 1) = output
End While
End If
FileClose(1)
If lstDate.Items.Contains("No assignments yet!") = False Then
SortByDate()
End If
End Sub
Private Sub CheckBox1_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox1.CheckedChanged
If CheckBox1.Checked = True Then
Call SortMyLife()
CheckBox1.Checked = False
End If
End Sub
End Class
frmAdd (for adding a new assignment)
Public Class frmAdd
Dim temparray() As String = {}
Dim temparray2() As String = {}
Dim dates() As Date = {}
Dim sorted As Boolean
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
Dim datedue As Date = dtpDue.Text
Dim Subject As String = cbxSbjct.Text
Dim Additional As String = rtfAN.Text
Dim Path As String = Application.StartupPath & "Assignments.crw"
If datedue > Now() Then
If Subject <> "Choose a subject" Then
FileOpen(1, Path, OpenMode.Append)
Dim output As String = dtpDue.Text & "-" & Subject & "_" & Additional
If frmSplashscreen.lstAssignments.Items.Contains("No assignments yet!") Then
frmSplashscreen.lstAssignments.Items.Clear()
frmSplashscreen.lstDate.Items.Clear()
frmSplashscreen.lstAN.Items.Clear()
End If
frmSplashscreen.lstAssignments.Items.Add(Mid(output, InStr(output, "-") + 1, InStr(output, "_") - (InStr(output, "-") + 1)))
frmSplashscreen.lstAN.Items.Add(Mid(output, InStr(output, "_") + 1, output.Length))
frmSplashscreen.lstDate.Items.Add(dtpDue.Text)
PrintLine(1, output)
FileClose(1)
For Each x In frmSplashscreen.lstDate.Items
MsgBox(x)
Next
Me.Close()
frmSplashscreen.Show()
Else
MsgBox("Please enter a subject in the box provided")
End If
Else
MsgBox("Please enter a date in the future", vbInformation, "Error")
End If
End Sub
End Class
Thank you for the help!

Answer 1

Have you tried something as simple as ListBoxHoliday.Items.Clear before the sort happens?