VBA文字限定词清洗程序

Question

I am writing a block of code which is going to read a line text from a file of comma delimited data and clean out any text qualifiers "" which are extra. Every field needs 1 set. trouble is the files wont have line breaks(cant be changed) so its going to be read in as 1 long string. everything is fine up until a line is supposed to switch over where the ,"","", runs up against ,"""", at the line end. I know how many fields there are in each line so finding this field isn't a problem. I have been wracking my brain for 4 hours trying to figure out how to differentiate the two sets of text qualifiers while also having the cleaning part of it clear out any extras if there are any. These are examples that would need to be cleaned

,""10/20/18"""",        >>> ,"10/20/18""",  
,"10/20/18"""4380012"", >>> ,"10/20/18""4380012",  
,"10/20"/18""4380012",  >>> ,"10/20/18""4380012",
,""""4380012",          >>> ,"""4380012",

my first idea was to mark the positions of the two outer commas and save the distance between them. I know at the very least there is supposed to be a pair of quotes between the fields so I thought moving an i and i+1 through the field might be a good way to figure out where its supposed to go but i couldn't determine the best configuration to do this.
then i thought walking in from either side by doing i=i+1 and n=n-1 from the left and right sides respectively but i ran in to similar difficulties.

the biggest problem was when there were extra qualifiers on the inner or outer edges and the other field was blank.

'My String
strLn as String
'Total number of quotes, good path = 4, bad path > 4
QuoteTotal as Integer
'the First quotes position
FirstQ as Integer
'The Ending quote position
RightQ as Integer
'Counter equals the position of the leading comma
Counter as Integer
'holds the quote character for use throughout code
Q as String
Q = Chr(34)
'Holds the comma character for use throughout the code
C as String
C = Chr(44)
'Holds the position of the last quote and the number of quotes between the fields
Dim LFieldQ As Integer
Dim LFieldQTotal As Integer
LFieldQ = 0
LFieldQTotal = 0
'Tracks position and length of the first data we find moving left to right
Dim LData as Integer
Dim LDatalen as Integer

    For i = Counter To Len(strLn)
        If (Mid(strLn, i, 1) = Q) Then
            LFieldQTotal = LFieldQTotal + 1
        End If
        If (Mid(strLn, i + 1, 1) = Q And Mid(strLn, i + 2, 1) = C) Then
            LFieldQTotal = LFieldQTotal + 1
            LFieldQ = i + 1
            Exit For
        End If
    Next

    If (LFieldQTotal <> 4) Then
        For i = FirstQ + 1 To LFieldQ
            If (Mid(strLn, i, 1) = Q) Then
                strLn = Mid(strLn, 1, i - 1) & Replace(strLn, Q, "", i, 1)
            ElseIf (Mid(strLn, i, 1) <> Q) Then
                LData = i
                For n = i To LFieldQ
                    If (Mid(strLn, n, 1) = Q) Then
                        LDatalen = n - 1
                        i = n
                        Exit For
                    End If
                Next
            End If
        Next
    End If

(i'm aware this is incomplete)
this block was my current attempt for walking the i and i+1 through the field. i'm getting caught up on having happy path exits but i shouldn't because the outer if statement has already determined we aren't going to find a happy path.
i want the cleaning aspect to be able to clean out any number of and any combination of extra qualifiers which may also be an unnecessary criteria i'm placing on it because in all honesty there will only ever potentially be one complete extra set placed in a field but i want it to work for all eventualities. any thoughts would be appreciated. not looking for a solved block of code but any push in the right direction would be great.

Answer 1

a piece of information I didn't know at the beginning was there will always be a value in the right field so I would only have to deal with examples such as

,"""""4380012",         >>> ,"""4380012",
,""""4380012"",         >>> ,"""4380012",
,""10/20/18"""4380012", >>> ,"10/20/18""4380012",

this made the ambiguous nature of where the fields lay in a bunch of quotes much easier to manage. below is my final product which appears to work in all the cases I need it to.

Private Sub TestSub()
Dim strLn As String
Dim i As Integer
Dim n As Integer
Dim s As Integer
Dim Q As String
Q = Chr(34)

strLn = "," & Q & Q & Q & "ABC" & Q & Q & Q & Q & Q & "DEF" & Q & ","
LfieldQ = Len(strLn) - 1
MsgBox (strLn)
n = LfieldQ

Do While n > FirstQ
    If (Mid(strLn, n, 1) = Q And Mid(strLn, n - 1, 1) = Q And (n = LfieldQ)) Then
        strLn = Mid(strLn, 1, n - 2) & Replace(strLn, Q, "", n - 1, 1)
        LfieldQ = LfieldQ - 1
        n = n + 1
    ElseIf (Mid(strLn, n, 1) = Q And Mid(strLn, n - 1, 1) <> Q And (n = LfieldQ)) Then
        For i = n - 1 To FirstQ Step -1
            If (Mid(strLn, i, 1) = Q) Then
                n = i
                Exit For
            End If
        Next i
        If (Mid(strLn, n, 1) = Q And Mid(strLn, n - 1, 1) = Q) Then
            n = n - 1
            For i = n - 1 To FirstQ Step -1
                If (Mid(strLn, i, 1) = Q And i <> FirstQ) Then
                    strLn = Mid(strLn, 1, i - 1) & Replace(strLn, Q, "", i, 1)
                ElseIf (Mid(strLn, i, 1) <> Q) Then
                    For s = i To FirstQ Step -1
                        If (Mid(strLn, s, 1) = Q And s <> FirstQ) Then
                            strLn = Mid(strLn, 1, s - 1) & Replace(strLn, Q, "", s, 1)
                            Exit For
                        End If
                    Next
                End If
            Next
        End If



    End If
    n = n - 1
Loop
MsgBox (strLn)
End Sub