Send print commands directly to LPT parallel port using C#.net [duplicate]
As in DOS we can do:
ECHO MESSAGE>LPT1
How can we achieve same thing in C# .NET?
Sending information to COM1 seems to be easy using C# .NET.
What about LPT1 ports?
I want to send Escape commands to the thermal printer.
In C# 4.0 and later its possible, first you need to connect to that port using the CreateFile
method then open a filestream to that port to finally write to it.
Here is a sample class that writes two lines to the printer on LPT1
.
using Microsoft.Win32.SafeHandles;
using System;
using System.IO;
using System.Runtime.InteropServices;
namespace YourNamespace
{
public static class Print2LPT
{
[DllImport("kernel32.dll", SetLastError = true)]
static extern SafeFileHandle CreateFile(string lpFileName, FileAccess dwDesiredAccess,uint dwShareMode, IntPtr lpSecurityAttributes, FileMode dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile);
public static bool Print()
{
string nl = Convert.ToChar(13).ToString() + Convert.ToChar(10).ToString();
bool IsConnected= false;
string sampleText ="Hello World!" + nl +
"Enjoy Printing...";
try
{
Byte[] buffer = new byte[sampleText.Length];
buffer = System.Text.Encoding.ASCII.GetBytes(sampleText);
SafeFileHandle fh = CreateFile("LPT1:", FileAccess.Write, 0, IntPtr.Zero, FileMode.OpenOrCreate, 0, IntPtr.Zero);
if (!fh.IsInvalid)
{
IsConnected= true;
FileStream lpt1 = new FileStream(fh,FileAccess.ReadWrite);
lpt1.Write(buffer, 0, buffer.Length);
lpt1.Close();
}
}
catch (Exception ex)
{
string message = ex.Message;
}
return IsConnected;
}
}
}
Assuming your printer is connected on the LPT1
port, if not you will need to adjust the CreateFile
method to match the port you are using.
you can call the method anywhere in your program with the following line
Print2LPT.Print();
I think this is the shortest and most efficient solution to your problem.
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