C#

Craig G Fraser wrote:

This may sound like a really stupid question but do all printers that are connected to a PC have a name, even if it is not on a network?

Heath Stewart wrote:

If you want to find out the printer name on a specific LPT port, you could P/Invoke EnumPrinters http://msdn.microsoft.com/library/en-us/gdi/prntspol_9fjn.asp[^] and enumerate the printers till you find one installed on LPTx: (keeping in mind that a printer can be on more than one LPT port, so in that case a comma-delimited list is returned so be sure to parse that as well).

using System;<br />
using System.Management;<br />
using System.Collections;<br />
<br />
namespace VTG.Functions<br />
{<br />
	public class PrintFunctions<br />
	{<br />
		public struct PrinterInfo<br />
		{<br />
			public string sPrinterName;<br />
			public bool bShared;<br />
			public string sSharedName;<br />
			public string sServerName;<br />
			public string sPortName;<br />
			public bool bDefaultPrinter;<br />
		}<br />
<br />
		public static PrinterInfo[] GetPrintersCollection()<br />
		{<br />
			PrinterInfo[] pi = new PrinterInfo[10];<br />
			string searchQuery = "SELECT * FROM Win32_Printer";<br />
			ManagementObjectSearcher searchPrinters = <br />
				new ManagementObjectSearcher(searchQuery);<br />
			ManagementObjectCollection printerCollection = searchPrinters.Get();<br />
			int iPrinterIndex=0;<br />
			foreach(ManagementObject printer in printerCollection)<br />
			{<br />
				pi[iPrinterIndex].sPrinterName=printer.Properties["Name"].Value.ToString();<br />
				pi[iPrinterIndex].bShared=Convert.ToBoolean(printer.Properties["Shared"].Value);<br />
				if (pi[iPrinterIndex].bShared==true)<br />
				{<br />
					pi[iPrinterIndex].sSharedName=printer.Properties["ShareName"].Value.ToString();<br />
					pi[iPrinterIndex].sServerName=printer.Properties["ServerName"].Value.ToString();<br />
				}<br />
				pi[iPrinterIndex].sPortName=printer.Properties["PortName"].Value.ToString();<br />
				pi[iPrinterIndex].bDefaultPrinter=Convert.ToBoolean(printer.Properties["Default"].Value);<br />
<br />
				iPrinterIndex++;<br />
			}<br />
			return pi;<br />
		}<br />
	}<br />
}

public class MyForm : Form
{
  // ...
  protected override void OnPaint(PaintEventArgs e)
  {
    base.OnPaint(e);
 
    Graphics g = e.Graphics;
    g.DrawLine(...);
  }
}

void AssignImage(Image img)
{
  if (!pictureBox1.InvokeRequired)
  {
    pictureBox1.Image = img;
  }
  else
  {
    MethodInfo setMethod = pictureBox1.GetType().GetProperty("Image").GetSetMethod();
    MethodInfoInvokeHandler d = new MethodInfoInvokeHandler(setMethod.Invoke);
    pictureBox1.Invoke(d, new object[] {pictureBox1, new object[] {img}});
  }
}
delegate object MethodInfoInvokeHandler(object obj, object[] parameters);