execute Run function and pass HTML file in 'filename'. add ghtmldoc.exe file in bin folder. Your HTML file would be created at \\Upload\\Invoice folder.
public string Run(string filename)
{
string sFileName = filename;
string m_Directory = Server.MapPath("~");
System.Diagnostics.Process pProcess = new System.Diagnostics.Process();
pProcess.StartInfo.FileName = m_Directory + "\\bin\\ghtmldoc.exe";
pProcess.StartInfo.Arguments = "--webpage --datadir " + m_Directory + " --quiet --bodyfont Helvetica --size Letter --left 0.6in --right 0.4in --linkstyle plain --linkcolor #000ff --top 0.5in --fontsize 10 --footer t / --header ... -t pdf14 --jpeg -f " + sFileName + "_t.pdf " + sFileName + ".html";
pProcess.StartInfo.WorkingDirectory = m_Directory + "\\Upload\\Invoice";
pProcess.Start();
Response.Write("Started : " + DateTime.Now.ToLongTimeString());
pProcess.WaitForExit(20000);
Response.Write("Done : " + DateTime.Now.ToLongTimeString());
return "";
}