Get Printer Port Number in c#

Question

I want to get my printer's port number in c#

I have tried using Win32_Printer and PrinterSettings

//Required namespaces
using System.Management;
using System.Drawing.Printing;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.Printing;
using System.IO.Ports;
using System.Net;

            String printerName = "My printer name";
            //String query = String.Format("Select Name, PortName from Win32_Printer WHERE Name LIKE '%{0}'", printerName);
            String query = String.Format("Select * from Win32_Printer WHERE Name LIKE '%{0}'", printerName);
            ManagementObjectSearcher printers = new ManagementObjectSearcher(query);
            foreach (ManagementObject printer in printers.Get())
            {
                DeviceName = (string)printer.GetPropertyValue("Name");
                //Console.WriteLine(DeviceName);
                PortName = (string)printer.GetPropertyValue("PortName");
                //Console.WriteLine(PortName);
            } 


        PrinterSettings ps = new PrinterSettings();
        ps.PrinterName = printerName;

I can get is port name , but not the port number, please help.

The days that printers used ports are long gone, they now use USB or the network. This is just guessing when you don't document what you got from the query. — Hans Passant, Oct 22 '14 at 10:28

Jared Feldman · Answer 1 · 2017-04-03T19:36:52.670

Using Microsoft's WMI Code Creator v1.0 tool, I found you can access PortNumber for Standard TCP/IP Ports via Win32_TCPIPPrinterPort.

using System;
using System.Management;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                ManagementObjectSearcher searcher =
                    new ManagementObjectSearcher("root\\CIMV2",
                    "SELECT * FROM Win32_TCPIPPrinterPort");

                foreach (ManagementObject queryObj in searcher.Get())
                {
                    Console.WriteLine("-----------------------------------");
                    Console.WriteLine("Win32_TCPIPPrinterPort instance");
                    Console.WriteLine("-----------------------------------");
                    Console.WriteLine("Name: {0}", queryObj["Name"]);
                    Console.WriteLine("PortNumber: {0}", queryObj["PortNumber"]);
                }
            }
            catch (ManagementException e)
            {
               Console.WriteLine("An error occurred while querying for WMI data: " + e.Message);
            }

            Console.ReadKey();
        }
    }
}

score 0 · Answer 2 · answered Apr 04 '17 at 05:41

ManagementObject has a properties property, which returns collection of PropertyData objects.

https://msdn.microsoft.com/en-us/library/system.management.managementbaseobject.properties(v=vs.110).aspx

From PropertyData you can get Name and Value. Just iterate all properties, you may find the port number.

https://msdn.microsoft.com/en-us/library/system.management.propertydata(v=vs.110).aspx

Below is pseudo code: (untested)

        foreach (ManagementObject printer in printers.Get())
        {
            foreach (PropertyData property in printer.properties)
            {
                 Console.WriteLine(property.Name);
                 Console.WriteLine(property.Value);

            }
        }

score 0 · Answer 3 · answered Jan 29 '18 at 10:59

using System;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.Collections.Generic;
using static System.Net.Mime.MediaTypeNames;

namespace ConsoleApp1
{
    class Myclass
    {
                 //PortType enum
                //struct for PORT_INFO_2
                [StructLayout(LayoutKind.Sequential)]
                public struct PORT_INFO_2
                {
                    public string pPortName;
                    public string pMonitorName;
                    public string pDescription;
                    public PortType fPortType;
                    internal int Reserved;
                }


                [Flags]
                public enum PortType : int
                {
                    write = 0x1,
                    read = 0x2,
                    redirected = 0x4,
                    net_attached = 0x8
                }

                //Win32 API
                [DllImport("winspool.drv", EntryPoint = "EnumPortsA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
                public static extern int EnumPorts(string pName, int Level, IntPtr lpbPorts, int cbBuf, ref int pcbNeeded, ref int pcReturned);
  

        /// <summary>
        /// method for retrieving all available printer ports
        /// </summary>
        /// <returns>generic list populated with post names (i.e; COM1, LTP1, etc)</returns>

          public List<string> GetPortNames()
            {
                //variables needed for Win32 API calls
                int result; int needed = 0; int cnt = 0; IntPtr buffer = IntPtr.Zero; IntPtr port = IntPtr.Zero;

                //list to hold the returned port names
                List<string> ports = new List<string>();

                //new PORT_INFO_2 for holding the ports
                PORT_INFO_2[] portInfo = null;

                //enumerate through to get the size of the memory we need
                result = EnumPorts("", 2, buffer, 0, ref needed, ref cnt);
                try
                {
                    //allocate memory
                    buffer = Marshal.AllocHGlobal(Convert.ToInt32(needed + 1));

                    //get list of port names
                    result = EnumPorts("", 2, buffer, needed, ref needed, ref cnt);

                    //check results, if 0 (zero) then we got an error
                    if (result != 0)
                    {
                        //set port value
                        port = buffer;

                        //instantiate struct
                        portInfo = new PORT_INFO_2[cnt];

                        //now loop through the returned count populating our array of PORT_INFO_2 objects
                        for (int i = 0; i < cnt; i++)
                        {
                            portInfo[i] = (PORT_INFO_2)Marshal.PtrToStructure(port, typeof(PORT_INFO_2));
                            port = (IntPtr)(port.ToInt32() + Marshal.SizeOf(typeof(PORT_INFO_2)));
                    }
                    port = IntPtr.Zero;
                }
                    else
                        throw new Win32Exception(Marshal.GetLastWin32Error());

                    //now get what we want. Loop through al the
                    //items in the PORT_INFO_2 Array and populate our generic list
                    for (int i = 0; i < cnt; i++)
                    {
                        ports.Add(portInfo[i].pPortName);                        
                }

                //sort the list
                ports.Sort();

                return ports;
            }
                catch (Exception ex)
                {
                    Console.WriteLine(string.Format("Error getting available ports: {0}", ex.Message));
                    Console.ReadLine();
                return null;
                }
                finally
                {
                    if (buffer != IntPtr.Zero)
                    {
                        Marshal.FreeHGlobal(buffer);
                        buffer = IntPtr.Zero;
                        port = IntPtr.Zero;
                    }
                }
             
            }

        [STAThread]
        static void Main()
        {
            Myclass m = new Myclass();
            
            foreach (var item in m.GetPortNames())
            {
                Console.WriteLine(item.ToString());
            }
           
            Console.Read();
        }
    } 
}

Get Printer Port Number in c#

I can get is port name , but not the port number, please help.

3 Answers3