My take on this with 2018 stuff.
I am using async. I am streaming to and from wkhtmltopdf. I created a new StreamWriter because wkhtmltopdf is expecting utf-8 by default but it is set to something else when the process starts.
I didn't include a lot of arguments since those varies from user to user. You can add what you need using additionalArgs.
I removed p.WaitForExit(...) since I wasn't handling if it fails and it would hang anyway on await tStandardOutput. If timeout is needed, then you would have to call Wait(...) on the different tasks with a cancellationtoken or timeout and handle accordingly.
public async Task<byte[]> GeneratePdf(string html, string additionalArgs)
{
ProcessStartInfo psi = new ProcessStartInfo
{
FileName = @"C:\Program Files\wkhtmltopdf\wkhtmltopdf.exe",
UseShellExecute = false,
CreateNoWindow = true,
RedirectStandardInput = true,
RedirectStandardOutput = true,
RedirectStandardError = true,
Arguments = "-q -n " + additionalArgs + " - -";
};
using (var p = Process.Start(psi))
using (var pdfSream = new MemoryStream())
using (var utf8Writer = new StreamWriter(p.StandardInput.BaseStream,
Encoding.UTF8))
{
await utf8Writer.WriteAsync(html);
utf8Writer.Close();
var tStdOut = p.StandardOutput.BaseStream.CopyToAsync(pdfSream);
var tStdError = p.StandardError.ReadToEndAsync();
await tStandardOutput;
string errors = await tStandardError;
if (!string.IsNullOrEmpty(errors)) { /* deal/log with errors */ }
return pdfSream.ToArray();
}
}
Things I haven't included in there but could be useful if you have images, css or other stuff that wkhtmltopdf will have to load when rendering the html page:
- you can pass the authentication cookie using --cookie
- in the header of the html page, you can set the base tag with href pointing to the server and wkhtmltopdf will use that if need be
