Hi, we have been using EO.Pdf (version 4.0.60.2) in our production environment from past 1 month and pdf conversion is not consistent. It works most of the time but sometimes we get following error for same URL. If you try to convert html page to pdf consistently, you may end up getting error few times.
On following Page, you can find different urls for (download pdf, printable page, email page..). For download pdf link we use the EO.Pdf HtmlToPdf.ConvertUrl funtion where we pass in the URL of Printable Page. Sometimes user are able to download pdf fine while sometime it just reports following error message.
Message :The constructor to deserialize an object of type 'EO.Pdf.HtmlToPdfException' was not found.
We are using ASP.Net MVC 4 framework for our application. We are using following classes, extension and entities in our application for HTML to PDF conversion purpose.
public class PdfActionResult : ViewResult
{
public string Url { get; set; }
public string OutputFileName { get; set; }
public PdfActionResult(string url, string outputFileName)
{
this.Url = url;
this.OutputFileName = outputFileName.Replace(',','-');
}
public override void ExecuteResult(ControllerContext context)
{
HttpResponseBase response = context.HttpContext.Response;
IEntityController currentController = context.Controller as IEntityController;
if (null != currentController)
{
byte[] pdfBytes;
using (Isolated<PdfConverter> isolated = new Isolated<PdfConverter>())
{
pdfBytes = isolated.Value.Process(
new PdfParameters
{
Key = currentController.AppConfig.EoPdfKey,
Url = this.Url,
Header = string.Empty,
HideItemIds = "trPrintBreadCrumb;trPrintButtons;"
});
}
response.ContentType = "application/pdf";
// send the PDF document as a response to the browser for download
response.Clear();
response.AddHeader("Content-Type", "application/pdf");
response.AddHeader("Content-Disposition", "attachment; filename=" + this.OutputFileName + ".pdf;");
response.Flush();
response.BinaryWrite(pdfBytes);
response.Flush();
}
response.End();
}
}
/*************************************************************************/
[Serializable]
public class PdfParameters
{
public string Url { get; set; }
public string Header { get; set; }
public string Footer { get; set; }
public string Key { get; set; }
public string HideItemIds { get; set; }
}
public class PdfConverter : MarshalByRefObject
{
public byte[] Process(PdfParameters pdfParams)
{
System.IO.MemoryStream stream = new System.IO.MemoryStream();
try
{
EO.Pdf.Runtime.AddLicense(pdfParams.Key);
PdfDocument doc = new PdfDocument();
HtmlToPdf.Options.HeaderHtmlFormat = pdfParams.Header ?? "PDF converted from {url}<hr />";
HtmlToPdf.Options.FooterHtmlFormat = pdfParams.Footer ?? @"<hr /><div style=""text-align:right""><span style=""font-family:Arial,Verdana;font-size:9px;"">" + DateTime.Now.ToShortDateString() + @" | Page {page_number} of {total_pages}</span></div>";
HtmlToPdf.Options.OutputArea = new RectangleF(0.25f, 0.25f, 8f, 10f);
HtmlToPdf.Options.ZoomLevel = 0.6f;
HtmlToPdf.Options.InvisibleElementIds = pdfParams.HideItemIds ?? string.Empty;
HtmlToPdf.Options.AutoFitX = HtmlToPdfAutoFitMode.ShrinkToFit;
HtmlToPdf.Options.NoLink = true;
HtmlToPdf.ConvertUrl(pdfParams.Url, doc);
doc.Save(stream);
stream.Position = 0;
return stream.ToArray();
}
catch (Exception excp)
{
throw new Exception(string.Format("HtmlToPdf.ConvertUrl failed for-{0}", pdfParams.Url), excp);
}
finally
{
stream.Dispose();
}
}
}
/*************************************************************************/
//http://www.superstarcoders.com/blogs/posts/executing-code-in-a-separate-application-domain-using-c-sharp.aspx
//http://www.essentialobjects.com/forum/postst7494_EOPdf-worker-processqueue-leads-to-unreliable-conversions-JavaScript-stops-being-processed.aspx
public sealed class Isolated<T> : IDisposable where T : MarshalByRefObject
{
private AppDomain _domain;
private T _value;
public Isolated()
{
_domain = AppDomain.CreateDomain("Isolated:" + Guid.NewGuid(),
null, AppDomain.CurrentDomain.SetupInformation);
Type type = typeof(T);
_value = (T)_domain.CreateInstanceAndUnwrap(type.Assembly.FullName, type.FullName);
}
public T Value
{
get
{
return _value;
}
}
public void Dispose()
{
if(_domain != null)
{
AppDomain.Unload(_domain);
_domain = null;
}
}
}
/*************************************************************************/
Error Message with stack trace
Message :The constructor to deserialize an object of type 'EO.Pdf.HtmlToPdfException' was not found.
Source :T******.P****.Web
Stack Trace : at T******.P****.Web.Infrastructure.Concrete.PdfConverter.Process(PdfParameters pdfParams)
at T******.P****.Web.Infrastructure.Concrete.PdfActionResult.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult)
TargetSite :Byte[] Process(T******.P****.Web.Infrastructure.Concrete.PdfParameters)