Delphi 5：pdf中的总页数

Question

I am maintaining an old application that is built with Delphi 5. I need to determine the total number of pages in a given pdf file.

I guess I could translate any solution for plain C also.

The current solution I have is forking a pdftk process, and parse its output. But this is quite slow, so I was wondering if I could find a good open-source pdf parser library for delphi (5...)... And it seems it doesn't exist.

So I tried to implement things like looking into the file's raw content for occurences of "/Type /Page" or "/Count" or "Linearized ... /N". But none of these -nor a combination of them- work in every case.

So I wondered if I could find an open-source DLL that I could make use of from Delphi 5. But I couldn't find any neither. I stumbled upon iTextSharp but it is for .NET and I don't understand howto use it in a plain delphi5 program...

So my final thought is this : is there any change I could find the source code for -say- pdftk and compile it as a DLL? Could anyone point me to the right direction?

Is there any solution I am missing?

I thank you in advance for your help!

Answer 1

Did you try to use the PDFLib dll ?

It is a very efficient library, and they have binding for Delphi, either via COM or via their dll. I guess you could use Delphi 5 with this library.

Answer 2

Did you try to run the free pdfinfo tool?

Download it from http://www.foolabs.com/xpdf

It returns such information:

Title:          Optimizing software in C++
Keywords:       software C++ optimization compiler
Author:         Agner Fog
Creator:        Microsoft® Word 2013
Producer:       Microsoft® Word 2013
CreationDate:   12/15/14 14:25:13
ModDate:        12/15/14 14:25:13
Tagged:         yes
Form:           none
Pages:          37
Encrypted:      no
Page size:      595.32 x 841.92 pts (A4) (rotated 0 degrees)
File size:      531693 bytes
Optimized:      no
PDF version:    1.5

So here you have your number of pages. And it is very fast.

Answer 3

If you install adobe acrobat (not reader) on user's PC then you can use OLE automation.

Here example how to open file and read pages count:

    uses
      ComObj, ActiveX;

    function TmyForm.IsOLEObjectInstalled(Name: String): Boolean;
    var
      ClassID: TCLSID;
      Rez: HRESULT;
    begin
      Rez := CLSIDFromProgID(PWideChar(WideString(Name)), ClassID);

      Result := (Rez = S_OK);
    end;

    procedure TmyForm.ButtonCheckPagesClick(Sender: TObject);
    var
      doc: OleVariant;
      pagesCount: Integer;
    begin
      if IsOLEObjectInstalled('AcroExch.PDDoc') then
      begin
        doc := CreateOleObject('AcroExch.PDDoc');

        if doc.Open('C:\test\test.pdf') then
        begin
          pagesCount := doc.GetNumPages;
          ShowMessageFmt('pages count = %d', [pagesCount]);
        end
        else
        begin
          ShowMessage('Can''t open file');
        end;
      end
      else
      begin
        ShowMessage('You must install adobe acrobat for that feature');
      end;
    end;