Trying to delete a line in a text file -VB - vb.net

Question

I'm very new to coding so any help is appreciated.
I've created a simple listbox that displays an array from a text file.
I wanted to add a textbox and a delete button so the user can type a word and then delete that line from the text file.
I've read many forums with various solutions for this but all have returned errors - currently I am getting this error: "System.IO.IOException: 'The process cannot access the file 'C:\Users\hches\source\repos\Inventory\Inventory\bin\Debug\Stock.txt' because it is being used by another process.'"
in sub DeleteLine()
Here is the relevant code to the Delete button and the respective DeleteLine() sub:
Private Sub BTDel_Click(sender As Object, e As EventArgs) Handles BTDel.Click
Dim sr As New StreamReader("Stock.txt")
Dim i As Integer = 0
Dim deleted As Boolean = False
If TBSearch.Text = "" Then
MsgBox("Please enter an Item to Delete.")
Else
Do Until sr.Peek() = -1 Or deleted = True 'prevents it from looping through the whole stock if the item is deleted
Dim Itm As String = sr.ReadLine()
If Itm.Contains(TBSearch.Text) Or Itm.ToLower.Contains(TBSearch.Text.ToLower) Then 'if the line read from the text contains the search word, continue
MsgBox(TBSearch.Text & " has been deleted.") 'simple messagebox says it has been deleted
DeleteLine()
deleted = True
TBSearch.Clear()
ElseIf sr.Peek() = -1 Then 'if it reaches the end of the document and it hasn't been found
MsgBox("Item has not been deleted.") 'message box appears saying it is not deleted
deleted = False
TBSearch.Clear()
End If
i = i + 1
Loop
End If
End Sub
Public Sub DeleteLine()
Dim line As Integer = 0
Dim Filename = "Stock.txt"
Dim TheFileLines As New List(Of String)
For line = 0 To TheFileLines.Count
TheFileLines.AddRange(System.IO.File.ReadAllLines(Filename))
' if line is beyond end of list then exit sub
If line >= TheFileLines.Count Then Exit Sub
TheFileLines.RemoveAt(line)
System.IO.File.WriteAllLines(Filename, TheFileLines.ToArray)
Next
End Sub
Many thanks for any guidance,
Henry
SOLVED -- For anyone interested I will post my solution, thanks for the help.
Public Sub DeleteLine()
ArrayLoad() 'populates my array from text file
File.Delete("Stock.txt") 'deletes original text file
Dim stockList As List(Of String) = ItemNames.ToList 'creates a list using my array
stockList.Remove(TBSearch.Text) 'removes the searched item from the list
File.Create("Stock.txt").Dispose() 'creates a new text file (same name as the original so the program will work fine)
Using sw As New StreamWriter("Stock.txt") 'sets up a streamwriter to write the new list to the text file
For Each item As String In stockList
sw.WriteLine(item)
Next
sw.Flush()
sw.Close()
End Using
End Sub
End Class