其实有很多这样的开源项目的，我接触过。你到网上搜搜，我记得有个Verypdf中，有个一htmltools，可以把单纯的网页文件转换为pdf，也可讲一个URL保存为pdf，希望能帮到你。

下载ITEXTSHARP

Document document = new Document(PageSize.A4, 10, 10, 10, 10);
            MemoryStream ms = new MemoryStream();
            PdfWriter writer = PdfWriter.GetInstance(document, ms);       
            StringReader se = new StringReader(htmlDisplayText);
            HTMLWorker obj = new HTMLWorker(document);       
            document.Open();

            obj.Parse(se);
            document.Close();     
            Response.Clear();
            Response.AddHeader("content-disposition", "attachment; filename=report.pdf");
            Response.ContentType = "application/pdf";                   
            Response.Buffer = true;       
            Response.OutputStream.Write(ms.GetBuffer(), 0, ms.GetBuffer().Length);
            Response.OutputStream.Flush();
            Response.End();