尝试此更新的代码，其中添加了一个检查，以在添加vbCrLf之前验证它是否是范围的最后一行。

Sub GenerateTxtFile()
    Dim ws As Worksheet
    Dim lastRow As Long
    Dim i As Long
    Dim filePath As String
    Dim txtData As String

    Set ws = ActiveSheet ' Switch to the specific sheet if necessary

    ' Gets the path to the Excel file
    filePath = ThisWorkbook.Path & "\RxH.txt"

    With ws
        lastRow = .Cells(.Rows.Count, "A").End(xlUp).Row

        ' Iterate through each row and build the TXT data
        
        For i = 2 To lastRow ' Start from row 2 to skip the row of headers
            Dim invoiceNo As String
            invoiceNo = .Cells(i, "C").Value
            Dim dashIndex As Long
            dashIndex = InStr(1, invoiceNo, "-")

            txtData = txtData & _
                Replace(.Cells(i, "A").Value, ",", "") & "|" & _
                "R1" & "|" & _
                Left(invoiceNo, dashIndex - 1) & "|" & _
                Mid(invoiceNo, dashIndex + 1) & "|" & _
                Format(.Cells(i, "B").Value, "dd/mm/yyyy") & "|" & _
                Replace(.Cells(i, "D").Value, ",", "")

            ' Adds a new line only if it is not the last row
            
            If i < lastRow Then
                txtData = txtData & vbCrLf ' vbCrLf add a new line
            End If
        Next i
    End With

    ' Writes TXT data to a file
    Open filePath For Output As #1
    Print #1, txtData ' Excludes the last extra line
    Close #1

    MsgBox "TXT file generated successfully!", vbInformation
End Sub