Converting AutoCAD Drawings to PDF

////////////////////////////////////////////////////////////////////////////////////////////////////
// This example was designed for using in Delphi 7 or higher.
//
// 1. Autodesk AutoCAD 2000 or above should be installed and activated on your PC.
//    Autodesk AutoCAD LT does not have COM interface and cannot be used as COM-server!
//
// 2. Universal Document Converter 5.2 or above should be installed, too.
//
// 3. Add "Universal Document Converter Type Library" and "AutoCAD XXXX Type Library" type libraries to the project.
//    XXXX is the AutoCAD version installed on your computer.
//
//    Delphi 7:
//      Use the Project | Import Type Library menu.
//    Delphi 2006 or latter:
//      Use the Component | Import Component menu.
//
//    Clear the "Generate Component Wrapper" checkbox and click the "Create Unit" button (Delphi 7) or
//    select the "Create Unit" option (Delphi 2006 or latter).
//
////////////////////////////////////////////////////////////////////////////////////////////////////

program AutoCADtoPDF;

{$APPTYPE CONSOLE}

uses
  SysUtils,
  Variants,
  Windows,
  Dialogs,
  ActiveX,
  UDC_TLB,
  AXDBLib_TLB,
  AutoCAD_TLB;

  procedure PrintAutoCADtoPDF(AutoCADFilePath: string);
  var
    objUDC: IUDC;
    Printer: IUDCPrinter;
    Profile: IProfile;
    App: AcadApplication;
    Doc: AcadDocument;
    Layout: AcadLayout;
    Version: Double;
    FormatSettings: TFormatSettings;
    ReadOnly, Password: OleVariant;
    nBACKGROUNDPLOT, nFILEDIA, nCMDDIA: OleVariant;
    xNull: OleVariant;
    SaveChanges: OleVariant;
  begin
    //Create a UDC object and get its interfaces
    objUDC := CoAPIWrapper.Create;
    Printer := objUDC.get_Printers('Universal Document Converter');
    Profile := Printer.Profile;

    //Use Universal Document Converter API to change settings of converterd drawing
    Profile.Load('C:\Program Files\Universal Document Converter\UDC Profiles\Drawing to PDF.xml');

    Profile.OutputLocation.Mode := LM_PREDEFINED;
    Profile.OutputLocation.FolderPath := 'c:\UDC Output Files';

    Profile.PostProcessing.Mode := PP_OPEN_FOLDER;

    App := CoAcadApplication.Create;

    //double Version = double.Parse(App.Version.Substring(0, 4), new CultureInfo("en-US"));

    GetLocaleFormatSettings($0409 {en_US}, FormatSettings);
    Version := StrToFloat(Copy(App.Version, 1, 4), FormatSettings);

    //Open drawing from file
    ReadOnly := False;
    Password := Variants.EmptyParam;
    Doc := App.Documents.Open(AutoCADFilePath, ReadOnly, Password);

    //Change AutoCAD preferences for scaling the drawing to page
    if Doc.ActiveSpace = acPaperSpace then
      Layout := Doc.PaperSpace.Layout
    else //Doc.ActiveSpace = acModelSpace
      Layout := Doc.ModelSpace.Layout;

    Layout.PlotType := acExtents;
    Layout.UseStandardScale := True;
    Layout.StandardScale := acScaleToFit;
    Layout.CenterPlot := True;

    nBACKGROUNDPLOT := 0;
    nFILEDIA := 0;
    nCMDDIA := 0;
    if Version >= 16.1 then
    begin
      nBACKGROUNDPLOT := Doc.GetVariable('BACKGROUNDPLOT');
      nFILEDIA := Doc.GetVariable('FILEDIA');
      nCMDDIA := Doc.GetVariable('CMDDIA');

      xNull := 0;
      Doc.SetVariable('BACKGROUNDPLOT', xNull);
      Doc.SetVariable('FILEDIA', xNull);
      Doc.SetVariable('CMDDIA', xNull);
    end;

    Doc.Plot.QuietErrorMode := True;

    //Plot the drawing
    Doc.Plot.PlotToDevice('Universal Document Converter');

    if Version >= 16.1 then
    begin
      //Restore AutoCAD default preferences
      Doc.SetVariable('BACKGROUNDPLOT', nBACKGROUNDPLOT);
      Doc.SetVariable('FILEDIA', nFILEDIA);
      Doc.SetVariable('CMDDIA', nCMDDIA);
    end;

    //Close drawing
    SaveChanges := False;
    Doc.Close(SaveChanges, Variants.EmptyParam);

    //Close Autodesk AutoCAD
    App.Quit();
  end;

var
  TestFilePath: string;
begin
  TestFilePath := ExtractFilePath(ParamStr(0)) + 'TestFile.dwg';
  try
    CoInitialize(nil);
    try
      PrintAutoCADtoPDF(TestFilePath);
    finally
      CoUninitialize;
    end;
  except
    on E: Exception do
      MessageDlg(E.ClassName + ' : ' + E.Message, mtError, [mbOK], 0);
  end;
end.