ASP.NET IIS server side printing fails

Question

I'm building an ASP.NET application that requires printing using PrintDocument method:

PrintDocument.Print()

Printing works properly in development env with IIS express. when publishing it to an intranet IIS server, printing fails, which I think is caused by permission issue for aspnet working process.

I tried to do the following with no success:

• I created an application pool in integrated pipeline mode for an admin local user with load user profile option set to true
• I moved the application to the new created application pool
• I added <identity impersonate="true" username="username" password="*****"/> in web.config file
• An error appeared stating that: An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode so I added <validation validateIntegratedModeConfiguration="false"/> to <system.webServer> section.

Any help please?

Answer 1

I think you might be misunderstanding some fundamental concepts here. When you use PrintDocument.Print() you are printing on the server. When you deploy your application in IIS this printing will happen on the server computer that is hosting your application. The reason why you thought your code was working in IIS Express is because you were hosting your application on the same computer as the client browser that was testing it. Also you were running your application under your account which had a printer configured.

You cannot print directly to the client computer from a web application. That would be a big security issue. The best you could do is provide some HTML document using a print media CSS type. Then if the user decides, he might print it in his browser.

If on the other hand you want to print on some printer that is attached to your web server, you will need to configure the Application Pool in IIS to run under an identity that has a printer configured in its profile.

Answer 2

Hopefully I am understanding your question correctly, but I just had some confusion myself with this. Our setup at my work is Windows Server 2008 R2 with IIS 7.

We have a print server as well installed on the same box (not sure if it matters as this is not my area of expert).

Basically, viewing the installed printers using, PrinterSettings.InstalledPrinters I was able to see all the printer names installed on the server.

I attach a debugger to the application process to debug and I can just use the debugger to see this, otherwise you will have to run a loop to print through these. If you run this locally, you will see only the printers installed on your machine. If they are network printers, then the full path will be shown. So determine the path/name the server will recognize the printer as and then set that to the printer name explicitly using the,

PrinterSettings.PrinterName property of the PrintDocument class. This worked for me. Also, my application pool identity is set to NetworkService.

Answer 3

I think the original poster has gotten a lot of flack for their question. If you want to generate .PDFs using GhostScript, for example, you install a printer driver and create a printer for it. You can suppress the Saveas() dialog in many languages by providing one ahead of time. This was feasible in earlier versions of IIS (that may have been less secure), but is harder to do in IIS 8.

I think this issue is caused by IIS inhibiting access to the local printer queue. This is either caused by not being in the NT AUTHORITY\INTERACTIVE group at runtime, or because IIS will put the user, (whomever is running the app pool) in two groups: IIS APPPOOL\, and BUILTIN\IIS_IUSRS.

You can validate all this by looking at the thread permissions using a tool like Sys Internal's Process Explorer.

Answer 4

I have faced same issue and I found the following solution and it worked for me.

1 - Go to printer and setting of system  
2 - Select Printer  
3 - Go to Printer Properties  
4 - Security  
5 - Click on Add "IIS AppPool\DefaultAppPool" as object name and click on check name (Default Pool will be your Pool Name)  
6 - Give permission Manage This Printer and Manage Document permission.  
7 - Restart IIS