Direct printing not working

[Guest]

Hi ALL
Please check the code below. OpenPrinter method returns Access is Denied error. Serial Printer is connected to the the IP address with name given at COM1
public enum ACCESS_MAS

PRINTER_ACCESS_ADMINISTER = 4
PRINTER_ACCESS_USE = 8
PRINTER_ALL_ACCESS = 98305

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)
public struct PRINTER_DEFAULTS

public string strDataType
public IntPtr ptrDevMode;
public ACCESS_MASK eDesiredAccess


[DllImport("winspool.drv", EntryPoint="OpenPrinterA", SetLastError=true, CharSet=CharSet.Auto, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)
public static extern long OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string strPrinterName, out IntPtr phPrinter, ref PRINTER_DEFAULTS pdDefaults)

public void TestPrint(string strData

IntPtr ptrPrinter;
PRINTER_DEFAULTS pdDefaults = new PRINTER_DEFAULTS();
pdDefaults.eDesiredAccess = ACCESS_MASK.PRINTER_ACCESS_ADMINISTER;

long lReturn = OpenPrinter("\\\\111.11.11.11\\Code 39", out ptrPrinter, ref pdDefaults
if(lReturn == 0 || ptrPrinter == IntPtr.Zero
{
int intError = Marshal.GetLastWin32Error()
Marshal.ThrowExceptionForHR(unchecked((int)0x80070000 | Marshal.GetLastWin32Error()))


Note: Also can anybody tell me the link to get the exact declaratons of these APIs
Please help. Thanx in advance

 

[Mattias Sjögren]

Please check the code below. OpenPrinter method returns Access is Denied error.

Do you have administer access to the printer?

[DllImport("winspool.drv", EntryPoint="OpenPrinterA", SetLastError=true, CharSet=CharSet.Auto, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
public static extern long OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string strPrinterName, out IntPtr phPrinter, ref PRINTER_DEFAULTS pdDefaults);

The return type here should be a bool, not long. And I wouldn't
recommend mixing CharSet.Auto with explciitly specifying the ANSI
version of the function as the entrypoint.

Note: Also can anybody tell me the link to get the exact declaratons of these APIs.

http://pinvoke.net is a good place to start looking. I'd declare it
like

[DllImport("winspool.drv", SetLastError=true, CharSet=CharSet.Auto)]
public static extern bool OpenPrinter(string strPrinterName, out
IntPtr phPrinter, ref PRINTER_DEFAULTS pdDefaults);



Mattias