Convert base64-encoded image in iTextsharp pdf

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I know this is a slightly old question, however I couldn't find a better solution for this. I'm facing an issue with iTextSharp when converting an HTML string to a PDF. The HTML contains an img tag with a base64-encoded image, but the image is not displaying in the resulting PDF. I'd appreciate any help or insights on how to resolve this problem.

What I have tried:

C#

strimg CEMDrawSignpath = "data:image/png;base64,iVBOR...II="
string htmlTable = @"
        <div class='content'>
          <table width='100%' style='" + pagecss.ToString() + @"'>
            <tr style='position: relative;'>
			   <td>
			      <img src='"+ CEMDrawSignpath + @"' />
               </td>
	        </tr>
          </table>
        </div>";

    hdnhtmltable.Value = htmlTable;
    MemoryStream memoryStream = new MemoryStream();
    PdfWriter pdfWriter = PdfWriter.GetInstance(doc, memoryStream);
    doc.Open();
    string CompanyName = lblTopCompanyname.Text;
    string htmlTable = hdnhtmltable.Value;
    XMLWorkerHelper.GetInstance().ParseXHtml(pdfWriter, doc, new 
    StringReader(htmlTable));
    doc.Close();
    Response.ContentType = "application/pdf";
    Response.AddHeader("content-disposition", 
       "attachment;filename=EngagementLetter.pdf");
    Response.BinaryWrite(memoryStream.ToArray());
    Response.End();

Posted 15-Oct-23 21:27pm

Member 12926744

Updated 25-Oct-23 7:27am

Deeksha Shenoy

v5

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Comments

Richard Deeming 16-Oct-23 3:47am

Firstly, I've removed the massive Base64 dump from your question, since the actual content is not relevant. It's enough to know that it's a valid Base64 representation of an image.

Secondly, the HTML you're generating does not have an img tag with a Base64-encoded image; it has an img tag with its src set to a variable you haven't described (lblcempath), followed by a Base64 string outside of the img tag. Start by explaining what's in that unknown variable, and why you would want to display a raw Base64 string to the user.

Member 12926744 16-Oct-23 5:11am

I have updated my code , as 'lblcempath' is not actually required and CEMDrawSignpath is the byte64 encoded image as it is taking from database.

Richard Deeming 16-Oct-23 5:19am

As far as I can see, you need a custom tag processor for the image tag - there's a VB.NET example in this SO question[^] which might point you in the right direction.

[no name] 16-Oct-23 11:23am

One has nothing to do with the other. You should be dealing with an actual "image" (converted or otherwise), and PDF "code"; not some "encoding".

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Sheikh Muhammad Haris · Answer 1 · 2023-10-16T21:20:00

I assume the issue is converting htmltext with image to pdf

Try changing the following line

XMLWorkerHelper.GetInstance().ParseXHtml(pdfWriter, doc, new StringReader(htmlTable));

with

using (var htmlMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(htmlTable)))
{                                
iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(pdfWriter, doc, htmlMemoryStream, System.Text.Encoding.UTF8);
}

and if you are using external css

using (var cssMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(cssText)))
{
using (var htmlMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(htmlTable)))
{ 
iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(pdfWriter, doc, htmlMemoryStream, cssMemoryStream);
}
}

Hope this help