LPR command to print pcl-file from windows service not working(Now a tray application)

问题

I've been looking around for a while for a possible solution and explanation, but I can't find anything really.

The following command is being run from a windows service. The same command does function if used directly in cmd. It does not return any errors or anything else for that matter.

    System.Diagnostics.Process process = new System.Diagnostics.Process();
    System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
    startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
    startInfo.FileName = "cmd.exe";
    startInfo.Arguments = "/C lpr.exe –S " + printerIP + " –P " + deviceName + " –o l " + fInfo.DirectoryName + @"\" + fInfo.Name;
    process.StartInfo = startInfo;
    process.Start();

It might just be some minor thing I'm missing, but I just can't see it. If it's possible to go around using the lpr-command with an easy alternative I'd love that, but I havent seen anything yet.

Edit: Forgot to add that the file I'm trying to send to the printer is a pcl file.

Edit2: When I run the command without the Hidden windowstyle and WaitForExit(5000) applied to the process then I can't seem to see any commandline written - all that appears is the empty command prompt.

Edit 3: Been toying a bit around with this now and I've come up with the following:

    System.Diagnostics.Process process = new System.Diagnostics.Process();
    System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
    startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
    startInfo.FileName = "lpr";
    startInfo.Arguments = " –S " + printerIP + " –P " + deviceName + " –o l " + fInfo.DirectoryName + @"\" + fInfo.Name;
    process.StartInfo = startInfo;
    process.Start();

The above code works if it is executed by a user clicking a button in a form. So I decided to change my code into running as a tray application, seeing as I thought this might solve the issues - yet it still seems to refuse being run. Could it be some sort of issue with it being run by a triggered timer or another thread? Or perhaps something to do with the rights of those methods?

回答1:

Change your code to this:

System.Diagnostics.Process process = new System.Diagnostics.Process();
System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
startInfo.FileName = "cmd.exe";
startInfo.Arguments = "/C C:\windows\Sysnative\lpr.exe –S " + printerIP + " –P " + deviceName + " –o l " + fInfo.DirectoryName + @"\" + fInfo.Name;
process.StartInfo = startInfo;
process.Start();

The issue is that you are trying to access a 64 bit application (lpr) from a 32 bit cmd.exe application. The simple solution is to use the sysnative directory.

http://www.samlogic.net/articles/sysnative-folder-64-bit-windows.htm

The 'Sysnative' folder is invisible in Windows Explorer If you start Windows Explorer and open the Windows folder on your hard disk, you may notice that the Sysnative folder is not shown. The main reason to this is that Windows Explorer is a 64-bit program (when run in a 64-bit Windows), and the Sysnative folder is only visible and accessible from 32-bit software. If 64-bit software need access to the 64-bit system folder in Windows, the only option is to use the System32 folder name (for example: C:\Windows\System32).

Using the 'Sysnative' folder will help you access 64-bit tools from 32-bit code Some tools in a 64-bit Windows only exist in a 64-bit version; there is no 32-bit version available. And some of these tools are located in the 64-bit System32 folder. One example is the nbtstat tool that is used to help troubleshoot NetBIOS name resolution problems. If you try to run the nbtstat tool from 32-bit code (for example from an application or from script) and use a path like C:\Windows\System32, you will get a "File not found" error. The file can not be found; although Windows Explorer shows that the nbtstat program file actually is located in the C:\Windows\System32 folder.
The solution to this (somewhat confusing) problem is to include the virtual Sysnative folder in the folder path when you want to run the tool. For example like this: C:\Windows\Sysnative\nbtstat.exe The file path above will give you access to the 64-bit nbtstat tool from a 32-bit application or from a 32-bit script. We recommend you to read this article / blog post (at Scottie’s Tech.Info) to get more details about this.

来源：https://stackoverflow.com/questions/11915241/lpr-command-to-print-pcl-file-from-windows-service-not-workingnow-a-tray-applic