how to pass html as a string using wkhtmltopdf?

Question

how to pass html as a string instead of url in wkhtmltopdf using asp.net, c#?

Answer 1

Redirecting STDIN is probably the easiest way to accomplish what you're trying to do.

One method of redirecting STDIN with wkhtmltopdf (in ASP.Net) is as follows:

    private void WritePDF(string HTML)
    {
        string inFileName,
                outFileName,
                tempPath;
        Process p;
        System.IO.StreamWriter stdin;
        ProcessStartInfo psi = new ProcessStartInfo();

        tempPath = Request.PhysicalApplicationPath + "temp\\";
        inFileName = Session.SessionID + ".htm";
        outFileName = Session.SessionID + ".pdf";

        // run the conversion utility
        psi.UseShellExecute = false;
        psi.FileName = "c:\\Program Files (x86)\\wkhtmltopdf\\wkhtmltopdf.exe";
        psi.CreateNoWindow = true;
        psi.RedirectStandardInput = true;
        psi.RedirectStandardOutput = true;
        psi.RedirectStandardError = true;

        // note that we tell wkhtmltopdf to be quiet and not run scripts
        // NOTE: I couldn't figure out a way to get both stdin and stdout redirected so we have to write to a file and then clean up afterwards
        psi.Arguments = "-q -n - " + tempPath + outFileName;

        p = Process.Start(psi);

        try
        {
            stdin = p.StandardInput;
            stdin.AutoFlush = true;

            stdin.Write(HTML);
            stdin.Close();

            if (p.WaitForExit(15000))
            {
                // NOTE: the application hangs when we use WriteFile (due to the Delete below?); this works
                Response.BinaryWrite(System.IO.File.ReadAllBytes(tempPath + outFileName));
                //Response.WriteFile(tempPath + outFileName);
            }
        }
        finally
        {
            p.Close();
            p.Dispose();
        }

        // delete the pdf
        System.IO.File.Delete(tempPath + outFileName);
    }

Note that the code above assumes that there's a temp directory available in your application directory. Also, you must explicitly enable write access to that directory for the user account used when running the IIS process.