count number of pages in a pdf file

[swetham]

I need to count the number of pages in a PDF file. I have used the below code,

Public Function getNumberOfPdfPages(ByVal fileName As String) As Integer
Using sr As New StreamReader(File.OpenRead(fileName))
Dim regex As New System.Text.RegularExpressions.Regex("/Type\s*/Page[^s]")
Dim matches As MatchCollection = regex.Matches(sr.ReadToEnd())

Return matches.Count
End Using
End Function

The above code is working fine for only some PDF files (PDF file versions will be different).

Is there any restriction like the PDF file should be of that version only?

Can anyone please help me out from this issue?

Thank you.

 

[swetham]

I tried to open the PDF files in notepad, then if the notepad text doesnt containf "Count" word, the above function is not returning the number of pages.

Is there any other way to count if the PDF file does not contain "Count" word.