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'Text File Handling - How to load a text file into list box for a given file name
'Using split function load a text file into list box.

Sub TextFileToListbox(lst As ListBox, filename As String)
    Dim items() As String, i As Long
    ' Read the file's contents, and split it into an array of strings.
    ' (Exit here if any error occurs.)
    items() = Split(ReadTextFileContents(filename), vbCrLf)
    ' Load all non-empty items into the ListBox.
    For i = LBound(items) To UBound(items)
        If Len(items(i)) > 0 Then lst.AddItem items(i)
    Next
End Sub
 
Function ReadTextFileContents(filename As String) As String
    Dim fnum As Integer, isOpen As Boolean
    On Error GoTo Error_Handler
    ' Get the next free file number.
    fnum = FreeFile()
    Open filename For Input As #fnum
    ' If execution flow got here, the file has been open without error.
    isOpen = True
    ' Read the entire contents in one single operation.
    ReadTextFileContents = Input(LOF(fnum), fnum)
    ' Intentionally flow into the error handler to close the file.
Error_Handler:
    ' Raise the error (if any), but first close the file.
    If isOpen Then Close #fnum
    If Err Then Err.Raise Err.Number, , Err.Description
End Function