using Page.RenderControl()

net_hunk · June 28th, 2007, 12:00 AM

I have a webpage which is displayed a series of times with different controls each time.

I have a function which has the code to generate the controls dynamically which is a called in the next button.

Now my requirement is that, whenever the user clicks the next button I have to capture the current page with the controls and the data in it (static) in the form of pdf file and finally at the last when the user clicks the submit button I have to merge the pdf files and pop it up .

To generate the pdf I am using a third party dll which needs html source of the page so to get that i am using the following code

protected void ExportToPDF()
{
try
{

System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
Page.RenderControl(oHtmlTextWriter);
oHtmlTextWriter.Flush();

string pageSoure = oStringWriter.ToString();
oHtmlTextWriter.Close();

PdfConverter pdfcon = new PdfConverter();
pdfcon.LicenseFilePath = Server.MapPath("Bin/");
pdfcon.PageWidth = 900;
pdfcon.PdfDocumentOptions.LeftMargin = 25;
pdfcon.PdfDocumentOptions.RightMargin = 25;
pdfcon.AvoidTextBreak = true;
pdfcon.PdfDocumentOptions.PdfPageOrientation = PDFPageOrientation.Landscape;
pdfcon.PdfDocumentOptions.PdfPageSize = PdfPageSize.A4;
pdfcon.PdfDocumentOptions.PdfCompressionLevel = PdfCompressionLevel.Normal;
pdfcon.SavePdfFromHtmlStringToFile(pageSoure, Request.PhysicalApplicationPath + @"\temp\" + pageID.ToString() + ".pdf");

pageSoure = "";

}
catch
{}
}

here I am using a third party dll to convert to pdf ....now wen i call this function in the next button I am getting an http error as "A page can have only one server-side Form tag."

Please help me regarding this .

Thanks in advance

Kevon Somsy · June 8th, 2011, 02:06 AM

Hi, i have the same problem. The only difference is that i started by a sample program from here:http://www.voip-sip-sdk.com/p_159-ho...urce-voip.html

Maybe you can find the mistake here - i couldn't

BrendaBessi · May 26th, 2014, 04:26 AM

Hi, try overriding the VerifyRenderingInServerForm method, like the following:

Code:

public override void VerifyRenderingInServerForm(Control control)
{ }

That worked for me and I hope it will help anyone that encounters this issue. Also I used a different third party component, this Word DLL written in C#, here is how you can try it out:

Code:

protected void ExportToPDF()
{
	System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
	System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
	Page.RenderControl(oHtmlTextWriter);
	string pageSoure = oStringWriter.ToString();

	DocumentModel document;
	HtmlLoadOptions option = new HtmlLoadOptions() { BaseAddress = this.Request.PhysicalApplicationPath };
	using (Stream htmlStream = new System.IO.MemoryStream(option.Encoding.GetBytes(pageSoure)))
		document = DocumentModel.Load(htmlStream, option);

	PageSetup page = document.Sections[0].PageSetup;
	page.PageWidth = 900;
	page.PageMargins.Left = 25;
	page.PageMargins.Right = 25;
	page.Orientation = Orientation.Landscape;
	page.PaperType = PaperType.A4;
	
	document.Save(Request.PhysicalApplicationPath + @"\temp\" + pageID.ToString() + ".pdf");
}

In one of my previous project I used it to convert HTML files (from various sources) into PDF files through C#. Also before showing them I needed to join these multiple files (this can also be easily done in this DLL with import method) and then export the generated PDF to an ASP.NET client.