Methods for Converting Office Documents to PDF or XPS with C#

using Word = Microsoft.Office.Interop.Word;
using Excel = Microsoft.Office.Interop.Excel;
using PowerPoint = Microsoft.Office.Interop.PowerPoint;
using Microsoft.Office.Core;

Word.WdExportFormat wd = Microsoft.Office.Interop.Word.WdExportFormat.wdExportFormatPDF;
Excel.XlFixedFormatType excelType = Microsoft.Office.Interop.Excel.XlFixedFormatType.xlTypePDF;
PowerPoint.PpSaveAsFileType ppType = Microsoft.Office.Interop.PowerPoint.PpSaveAsFileType.ppSaveAsPDF;

private bool Convert(string sourcePath, string targetPath, Word.WdExportFormat exportFormat)
{
    bool result;
    object paramMissing = Type.Missing;
    Word.ApplicationClass wordApplication = new Word.ApplicationClass();
    Word.Document wordDocument = null;
    try
    {
         object paramSourceDocPath = sourcePath;
         string paramExportFilePath = targetPath;
         Word.WdExportFormat paramExportFormat = exportFormat;
         bool paramOpenAfterExport = false;
         Word.WdExportOptimizeFor paramExportOptimizeFor =
         Word.WdExportOptimizeFor.wdExportOptimizeForPrint;
         Word.WdExportRange paramExportRange = Word.WdExportRange.wdExportAllDocument;
          int paramStartPage = 0;
          int paramEndPage = 0;
          Word.WdExportItem paramExportItem = Word.WdExportItem.wdExportDocumentContent;
          bool paramIncludeDocProps = true;
          bool paramKeepIRM = true;
          Word.WdExportCreateBookmarks paramCreateBookmarks =
          Word.WdExportCreateBookmarks.wdExportCreateWordBookmarks;
          bool paramDocStructureTags = true;
          bool paramBitmapMissingFonts = true;
          bool paramUseISO19005_1 = false;
          wordDocument = wordApplication.Documents.Open(
                                 ref paramSourceDocPath, ref paramMissing, ref paramMissing,
                                 ref paramMissing, ref paramMissing, ref paramMissing,
                                 ref paramMissing, ref paramMissing, ref paramMissing,
                                 ref paramMissing, ref paramMissing, ref paramMissing,
                                 ref paramMissing, ref paramMissing, ref paramMissing,
                                 ref paramMissing);

          if (wordDocument != null)
              wordDocument.ExportAsFixedFormat(paramExportFilePath,
              paramExportFormat, paramOpenAfterExport,
              paramExportOptimizeFor, paramExportRange, paramStartPage,
              paramEndPage, paramExportItem, paramIncludeDocProps,
              paramKeepIRM, paramCreateBookmarks, paramDocStructureTags,
              paramBitmapMissingFonts, paramUseISO19005_1,
              ref paramMissing);
              result = true;
    }
    finally
    {
        if (wordDocument != null)
        {
            wordDocument.Close(ref paramMissing, ref paramMissing, ref paramMissing);
            wordDocument = null;
        }
        if (wordApplication != null)
        {
            wordApplication.Quit(ref paramMissing, ref paramMissing, ref paramMissing);
            wordApplication = null;
        }
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();
        GC.WaitForPendingFinalizers();
    }
    return result;
}

private bool Convert(string sourcePath, string targetPath, XlFixedFormatType targetType)
{
    bool result;
    object missing = Type.Missing;
    ApplicationClass application = null;
    Workbook workBook = null;
    try
    {
        application = new ApplicationClass();
        object target = targetPath;
        object type = targetType;
        workBook = application.Workbooks.Open(sourcePath, missing, missing, missing, missing, missing,
                           missing, missing, missing, missing, missing, missing, missing, missing, missing);
        workBook.ExportAsFixedFormat(targetType, target, XlFixedFormatQuality.xlQualityStandard, true, false, missing, missing, missing, missing);
        result = true;
    }
    catch
    {
        result = false;
    }
    finally
    {
        if (workBook != null)
        {
            workBook.Close(true, missing, missing);
            workBook = null;
        }
        if (application != null)
        {
            application.Quit();
            application = null;
        }
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();
        GC.WaitForPendingFinalizers();
    }
    return result;

}

By the way, I found a Free PDF Converter which can convert office files to PDF. That Free PDF Converter is also created via C#.

Convert PowerPoint to PDF

private bool Convert(string sourcePath, string targetPath, PpSaveAsFileType targetFileType)
{
        bool result;
        object missing = Type.Missing;
        ApplicationClass application = null;
        Presentation persentation = null;
        try
        {
                application = new ApplicationClass();
                persentation = application.Presentations.Open(sourcePath, MsoTriState.msoTrue, MsoTriState.msoFalse, MsoTriState.msoFalse);
                persentation.SaveAs(targetPath, targetFileType, Microsoft.Office.Core.MsoTriState.msoTrue);

                result = true;
        }
        catch
        {
                result = false;
        }
        finally
        {
                if (persentation != null)
                {
                        persentation.Close();
                        persentation = null;
                }
                if (application != null)
                {
                        application.Quit();
                        application = null;
                }
                GC.Collect();
                GC.WaitForPendingFinalizers();
                GC.Collect();
                GC.WaitForPendingFinalizers();
        }
        return result;
}

If we want to convert Word or Excel to XPS, we can use XPS virtual printer. After installing .Net Framework 3.5, the XPS virtual printer will be installed by default. And we set it as the default printer.

Microsoft XPS Document Writer

Word to XPS

public void PrintWord(string wordfile)
{
        oWord.ApplicationClass word = new oWord.ApplicationClass();
        Type wordType = word.GetType();

        //Open Word Document

        oWord.Documents docs = word.Documents;
        Type docsType = docs.GetType();
        object objDocName = wordfile;
        oWord.Document doc = (oWord.Document)docsType.InvokeMember("Open", System.Reflection.BindingFlags.InvokeMethod, null, docs, new Object[] { objDocName, true, true });

        //Print and Export to Specified File
        //Use doc.PrintOut(); method. But it is complicated to call the parameters. Suggest to use Type.InvokeMember. We just set four main parameters to call PrintOut.

        Type docType = doc.GetType();
        object printFileName = wordfile + ".xps";
        docType.InvokeMember("PrintOut", System.Reflection.BindingFlags.InvokeMethod, null, doc, new object[] { false, false, oWord.WdPrintOutRange.wdPrintAllDocument, printFileName });

        //Quit Word
        wordType.InvokeMember("Quit", System.Reflection.BindingFlags.InvokeMethod, null, word, null);
}

Excel to XPS

public void PrintExcel(string execlfile)
{
        Excel.ApplicationClass eapp = new Excel.ApplicationClass();
        Type eType = eapp.GetType();
        Excel.Workbooks Ewb = eapp.Workbooks;
        Type elType = Ewb.GetType();
        object objelName = execlfile;
        Excel.Workbook ebook = (Excel.Workbook)elType.InvokeMember("Open", System.Reflection.BindingFlags.InvokeMethod, null, Ewb, new Object[] { objelName, true, true });

        object printFileName = execlfile + ".xps";

        Object oMissing = System.Reflection.Missing.Value;
        ebook.PrintOut(oMissing, oMissing, oMissing, oMissing, oMissing, true, oMissing, printFileName);

        eType.InvokeMember("Quit", System.Reflection.BindingFlags.InvokeMethod, null, eapp, null);
}

In the same manner, if a PDF virtual printer is installed on the computer, for example, 5D PDF, we can set it as the default printer to convert other formats to PDF.

Also, we can put the methods in a Windows Service to do background conversion of documents.