はテストされていないが、Microsoft.Office.Interop.Word.Applicationは
Microsoft.Office.Interop.Word.Application word = new Microsoft.Office.Interop.Word.Application();
object missingvalue = System.Reflection.Missing.Value;
object dummyfilename = "D://DummyFile.docx";
string pdfdata = "D://HtmlFileData.html";
string pdffilename= "D://PDFFile.pdf";
object savechanges = Microsoft.Office.Interop.Word.WdSaveOptions.wdDoNotSaveChanges;
object ofalse = false;
Microsoft.Office.Interop.Word.Document doc = word.Documents.Open(ref dummyfilename, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue, ref missingvalue);
doc.Words.Last.InsertFile(pdfdata, ref missingvalue, ref ofalse, ref missingvalue, ref missingvalue);
doc.ExportAsFixedFormat(pdffilename, Microsoft.Office.Interop.Word.WdExportFormat.wdExportFormatPDF, false, Microsoft.Office.Interop.Word.WdExportOptimizeFor.wdExportOptimizeForOnScreen, Microsoft.Office.Interop.Word.WdExportRange.wdExportAllDocument, 1, 1, Microsoft.Office.Interop.Word.WdExportItem.wdExportDocumentWithMarkup, true, true, Microsoft.Office.Interop.Word.WdExportCreateBookmarks.wdExportCreateNoBookmarks, true, true, false, ref missingvalue);
doc.Close(ref savechanges,ref missingvalue,ref missingvalue);
word.Quit(ref savechanges, ref missingvalue, ref missingvalue);
これを参照することができ、 https://forums.asp.net/t/1899940.aspxを助けますか?ダウンロード+ pdf + without + + itextsharp + in + gridview –