VBA dir() returns empty string - vba

Question

I'm trying to get this vba working. It reads the correct filestructure and it does find the first .xlsx and it import the needed data to the control.xlsm.
I notice that after it gets to fileName = dir() the fileName becomes empty. I read that it does this because it cannot find files that match the criteria, but what am i doing wrong?
Here is the code
Sub test_werk_final()
Application.ScreenUpdating = False
Application.CutCopyMode = False
Application.DisplayAlerts = False
Dim directory, fileName As String, sheet As Worksheet
directory = ThisWorkbook.Path & "\"
fileName = Dir(directory & "*.xlsx")
controlFile = Dir(directory & "control.xlsm")
lijn = 2
MsgBox "1" & directory & "2" & fileName & "3" & controlFile
Do Until fileName = ""
MsgBox "1" & directory & "2" & fileName & "3" & controlFile
Workbooks.Open fileName:=(directory & fileName)
MsgBox "1" & directory & "2" & fileName & "3" & controlFile
naam = Sheets("Sheet2").Range("A1").Value
leeftijd = Sheets("Sheet2").Range("A2").Value
Workbooks(controlFile).Worksheets("control").Cells(lijn, 1) = naam
Workbooks(controlFile).Worksheets("control").Cells(lijn, 2) = leeftijd
For Each sheet In Workbooks(fileName).Worksheets
naam = Workbooks(fileName).Worksheets.Range("A1").Value
leeftijd = Workbooks(fileName).Worksheets.Range("A2").Value
Workbooks(controlFile).Worksheets("control").Cells(lijn, 1) = naam
Workbooks(controlFile).Worksheets("control").Cells(lijn, 2) = leeftijd
Next sheet
Workbooks(fileName).Close
MsgBox "1" & directory & "2" & fileName & "3" & controlFile
lijn = lijn + 1
MsgBox "1" & directory & "2" & fileName & "3" & controlFile
fileName = Dir() ' volgende
MsgBox "1" & directory & "2" & fileName & "3" & controlFile
Loop
Application.ScreenUpdating = True
I'm not an expert coding guru, but i do posses basic programming skills.
P.S: i already looked for the questone on differnt fora en didn't find anything that could help me. Maybe i used the wrong search string.
Thanks in advance

Answer 1

You should simple change the order of the two Dir-statements:
controlFile = Dir(directory & "control.xlsm")
fileName = Dir(directory & "*.xlsx")
When you issue a Dir-command with parameter, a new search is started according to the pattern you pass. Dir-command without parameter fetches the next file matching that pattern. In your code, you started first a search with wildcards and then a second search with a fixed filename. When you start your loop, the dir-command will try to find another file with name control.xlsm and of course fails.