Find the filename with highest number in a folder - regex

Question

I have a folder with a lot of files, they're named based on a pattern with an iterating number in it.
I'm trying to save new files through vb.net. The aim is to name it with the highest number of the folder +1
There for I looked on internet and found a lot of things about regex and Linq which helped me to make the following code :
If tmpFileName.Contains("%num%") Then
Dim lastFileNo As Integer = 1
Dim tmpFName = Dir(frmMain.saveLocalTFPath & "*.docx")
Dim numbers() As Integer = Regex.Split(tmpFName, "(?<alpha>[\w-[0-9]]+)(?<num>[\d]+)").Skip(1).Select(Function(s) Integer.Parse(s)).ToArray
For Each element In numbers
If element > 0 And element < 999 And element > lastFileNo Then lastFileNo = element
Next
Do Until tmpFName = ""
numbers = Regex.Split(tmpFName, "(?<alpha>[\w-[0-9]]+)(?<num>[\d]+)").Skip(1).Select(Function(s) Integer.Parse(s)).ToArray
For Each element In numbers
If element > 0 And element < 1000 And element > lastFileNo Then lastFileNo = element
Next
tmpFName = Dir()
Loop
tmpFileName = tmpFileName.Replace("%num%", lastFileNo)
End If
But it doesn't work as expected. Has it is my first code in Linq and in Regex and i'm not used to detect what is wrong in my code.
Can someone give a hint please?
Thanks

Answer 1

I'm pretty sure your regex is wrong. Split your code a little bit, create a function that pulls the number from a filename. Ex
Function GetNumberFromFilename(ByVal filename As String) As Integer
' From the filename parameter, pull the number and return it
End Function
Then it'll be easy to test it
Console.WriteLine(GetNumberFromFilename("JCR 2013-01 data.docx"))
When you got that working, just loop all the files get the highest number
Dim lastFileNo As Integer = 1
Dim files() As String = IO.Directory.GetFiles(frmMain.saveLocalTFPath, "*.docx")
For Each file As String In files
Dim number As Integer
number = GetNumberFromFilename(file)
If number > 0 And number < 1000 And number > lastFileNo Then
lastFileNo = number
End If
Next

Answer 2

It would be one of some possible solutions.
Dim di As New System.IO.DirectoryInfo("The Directory")
Dim max = (From f In di.GetFiles().AsQueryable()
Where IsNumeric(Path.GetFileNameWithoutExtension(f.Name))
Select Path.GetFileNameWithoutExtension(f.FullName)).
OrderBy(Function(c) c).LastOrDefault()

Answer 3

Yes the_lotus you're right but with matches in my cases instead of match.
I discovered it 30 minutes ago but I wanted to make it work before posting the solution.
Thanks to you I managed to assemble the peaces and this is the right code:
Dim lastFileNo As Integer = 1
Dim files() As String = Directory.GetFiles(frmMain.saveLocalTFPath, "*.docx")
For Each file As String In files
file = Path.GetFileNameWithoutExtension(file)
Dim numbers As MatchCollection = Regex.Matches(file, "(?<num>[\d]+)")
For Each number In numbers
number = CInt(number.ToString())
If number > 0 And number < 1000 And number > lastFileNo Then lastFileNo = number
Next
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