如何通过IIS中托管的应用程序打印到网络打印机

Question

I have scenario of printing pdf (generated from stream) to network printer through application hosted in IIS. I tried with PrintDocument.Print() and problem I'm facing is: 1. Document is getting queued to the print job queue with size 0 bytes. 2. Document is getting queued to the print job queue with owner name as machine_name. Here is the code which i tried using PdfiumViewer (to generate PrintDocument from bytearray) and System.Drawing.Printing.PrintDocument:

 public void SendPdfToPrinter(byte[] byteArray, string fileName, string printerNetworkPath)
    {
        using (Stream fileStream = new MemoryStream(byteArray)) //byte array for the file content
        {

            var printerSettings = new System.Drawing.Printing.PrinterSettings
            {
                PrinterName = printerNetworkPath, //this is the printer full name. i.e. \\10.10.0.12\ABC-XEROX-01
                PrintFileName = fileName, //file name. i.e. abc.pdf
                PrintRange = System.Drawing.Printing.PrintRange.AllPages,
            };
            printerSettings.DefaultPageSettings.Margins = new System.Drawing.Printing.Margins(0, 0, 0, 0);

            // Now print the PDF document
            using (PdfiumViewer.PdfDocument document = PdfiumViewer.PdfDocument.Load(fileStream))
            {
                using (System.Drawing.Printing.PrintDocument printDocument = document.CreatePrintDocument())
                {
                    printDocument.DocumentName = fileName;
                    printDocument.PrinterSettings = printerSettings;
                    printDocument.PrintController = new System.Drawing.Printing.StandardPrintController();
                    printDocument.Print();
                }
            }

Answer 1

For both the problems, answer is impersonating the user to do the printing.

In my case app pool is running under LocalSystem account which is obviously is not a domain user and printer is exposed to the domain user only.

Note: Application pool is 64bit, if you use 32bit you will face another set of challenges which is well described here: https://blogs.msdn.microsoft.com/winsdk/2015/05/19/printing-successfully-using-impersonation-from-a-32-bit-application-on-a-64-bit-system/

Below is code which required to do the impersonation for domain user:

 [PermissionSet(SecurityAction.Demand, Name = "FullTrust")]
public class Impersonation : IDisposable
{
    private readonly SafeTokenHandle _handle;
    private readonly WindowsImpersonationContext _context;
    bool disposed = false;

    const int LOGON32_PROVIDER_DEFAULT = 0;
    const int LOGON32_LOGON_INTERACTIVE = 2;

    public Impersonation(ImpersonateUserDetails user) : this(user.Domain, user.UserName, user.Password)
    { }
    public Impersonation(string domain, string username, string password)
    {
        var ok = LogonUser(username, domain, password,
                       LOGON32_LOGON_INTERACTIVE, 0, out this._handle);
        if (!ok)
        {
            var errorCode = Marshal.GetLastWin32Error();
            throw new ApplicationException(string.Format("Could not impersonate the elevated user.  LogonUser returned error code {0}.", errorCode));
        }

        this._context = WindowsIdentity.Impersonate(this._handle.DangerousGetHandle());
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (disposed)
            return;

        if (disposing)
        {
            this._context.Dispose();
            this._handle.Dispose();
        }           
        disposed = true;
    }

    ~Impersonation()
    {
        Dispose(false);
    }


    [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    private static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword, int dwLogonType, int dwLogonProvider, out SafeTokenHandle phToken);

    sealed class SafeTokenHandle : SafeHandleZeroOrMinusOneIsInvalid
    {
        private SafeTokenHandle()
            : base(true) { }

        [DllImport("kernel32.dll")]
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        [SuppressUnmanagedCodeSecurity]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool CloseHandle(IntPtr handle);

        protected override bool ReleaseHandle()
        {
            return CloseHandle(handle);
        }
    }
}

public class ImpersonateUserDetails
{
    public string UserName { get; set; }

    public string Password { get; set; }

    public string Domain { get; set; }
}

Answer 2

另一个可能且容易的解决方案是将您的应用程序池标识配置为具有访问/权限以在网络打印机中进行打印的自定义/域用户。