VB.NET - Find a string in a XML String - asp.net

Question

I am working on a project to read InfoPath XML files into a .NET form. I'm trying to get the .xsn version from the href in order to determine what version of the InfoPath form I should display. Since there is only 1 .xsn string in the XML File, I can use that, but I'm having trouble parsing out the file name.
http://servername/foldername/forms/fileNameV100.xsn

Answer 1

Here is an example of how you would parse the filename. You can use these techniques to parse out the version. Additional notes are in the comments of the code.
Private Function ParseXsnFileName(ByVal strTarget As String) As String
Dim strResult As String = String.Empty
'Get the location of where the .xsn extension starts.
Dim intExtensionLocation As Integer = strTarget.IndexOf(".xsn")
If intExtensionLocation >= 0 Then
'Now we will initiate a loop that iterates back character by character until we find
'the forward slash of the URL that preceedes the filename.
Dim bolStartFound As Boolean = False
Dim intCursor As Integer = intExtensionLocation
Do Until intCursor = 0 OrElse bolStartFound
If strTarget.Substring(intCursor, 1) = "/" Then
'Setting this to true exist the loop.
bolStartFound = True
End If
intCursor -= 1
Loop
If bolStartFound Then
'We found all of the pieces we need to parse out the filename.
'Add 2 because of the "intCursor -= 1" and because we don't want the / in the filename.
Dim intStartLocation As Integer = intCursor + 2
'Add 4 to StartLocation because we want the extension.
'Subtract intStartLocation from intExtensionLocation to get the length.
strResult = strTarget.Substring(intStartLocation, (intExtensionLocation - (intStartLocation + 4)))
End If
End If
Return strResult
End Function
Example Usage:
Dim strParseThis As String = "http://servername/foldername/forms/fileNameV100.xsn"
Dim strFileName As String = ParseXsnFileName(strParseThis)