在C＃Web API Web服务中使用Process（）调用GhostScript

Question

I am trying to print a pdf file from a WebAPI Web Service by calling GhostScript using Process()

This works perfectly when 'Debugging' an ASP.NET application on my local machine, but when I use the exact same code to try and print through a Web Service - also on my local machine - it doesn't work.

I don't get any kind of exception in VS - so far as the application is concerned, the application is working fine.

Here's the code I'm using to call the GhostScript printer:

Process process = new Process();

process.StartInfo.Arguments = @" -dPrinted -dBATCH -dNOPROMPT -dNOPAUSE -dNOSAFER -q -dNumCopies=1 -sDEVICE=mswinpr2 -dNoCancel -sPAPERSIZE=a4 -sOutputFile=\\spool\\\printserver\printer c:\\test\test.pdf";


process.StartInfo.FileName = @"C:\Program Files (x86)\GPLGS\gswin32c.exe";
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.RedirectStandardOutput = true;

StringBuilder output = new StringBuilder();
StringBuilder error = new StringBuilder();

using (AutoResetEvent outputWaitHandle = new AutoResetEvent(false))
using (AutoResetEvent errorWaitHandle = new AutoResetEvent(false))
{
    process.OutputDataReceived += (sender, e) => {
        if (e.Data == null)
        {
            outputWaitHandle.Set();
        }
        else
        {
            Console.Write(e.Data);
            output.AppendLine(e.Data);
        }
    };
    process.ErrorDataReceived += (sender, e) =>
    {
        if (e.Data == null)
        {
                errorWaitHandle.Set();
            }
            else
            {
                Console.Write(e.Data);
                error.AppendLine(e.Data);
            }
        };

    process.Start();

    process.BeginOutputReadLine();
    process.BeginErrorReadLine();
    process.WaitForExit();
    if (process.HasExited == false) process.Kill();
    return process.ExitCode == 0;

I thought this might have something to do with printers not being installed for All Users so have added them for all users. The only other thing that I can see it being is Permissions - but can't figure out a solution.

Does anyone have any ideas?

Thanks in advance for your help. :)

Answer 1

As suspected, this turned out to be a Permissions issue. After publishing the Web Service to IIS, I changed the Default Application Pool to use a User Identity, the printing suddenly started working correctly.

I will set up a user account specifically for printing - with no write permissions - and use this for now.