Enviando datos a la impresora USB en C#?

Question

Tengo un código de script para la impresora zebra TLP2844 en un archivo de texto. Necesito imprimir ese archivo de script en una impresora conectada a través de USB. Ejecuté ese script usando un puerto paralelo usando el comando DOS:

/c type filename.txt >PRN 

Pero la impresora está conectada a USB. ¿Cómo enviar comandos de impresión a usb? ¿Debo usar la clase printdocument?

Answer 1

Microsoft tiene este código de ejemplo disponible para su uso:

How to send raw data to a printer by using Visual C# .NET

using System; 
using System.Drawing; 
using System.Drawing.Printing; 
using System.IO; 
using System.Runtime.InteropServices; 
using System.Windows.Forms; 

public class RawPrinterHelper 
{ 
    // Structure and API declarions: 
    [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)] 
    public class DOCINFOA 
    { 
    [MarshalAs(UnmanagedType.LPStr)] public string pDocName; 
    [MarshalAs(UnmanagedType.LPStr)] public string pOutputFile; 
    [MarshalAs(UnmanagedType.LPStr)] public string pDataType; 
    } 
    [DllImport("winspool.Drv", EntryPoint="OpenPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd); 

    [DllImport("winspool.Drv", EntryPoint="ClosePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool ClosePrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint="StartDocPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di); 

    [DllImport("winspool.Drv", EntryPoint="EndDocPrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool EndDocPrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint="StartPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool StartPagePrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint="EndPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool EndPagePrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint="WritePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)] 
    public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten); 

    // SendBytesToPrinter() 
    // When the function is given a printer name and an unmanaged array 
    // of bytes, the function sends those bytes to the print queue. 
    // Returns true on success, false on failure. 
    public static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount) 
    { 
    Int32 dwError = 0, dwWritten = 0; 
    IntPtr hPrinter = new IntPtr(0); 
    DOCINFOA di = new DOCINFOA(); 
    bool bSuccess = false; // Assume failure unless you specifically succeed. 
    di.pDocName = "My C#.NET RAW Document"; 
    di.pDataType = "RAW"; 

    // Open the printer. 
    if(OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero)) 
    { 
     // Start a document. 
     if(StartDocPrinter(hPrinter, 1, di)) 
     { 
     // Start a page. 
     if(StartPagePrinter(hPrinter)) 
     { 
      // Write your bytes. 
      bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten); 
      EndPagePrinter(hPrinter); 
     } 
     EndDocPrinter(hPrinter); 
     } 
     ClosePrinter(hPrinter); 
    } 
    // If you did not succeed, GetLastError may give more information 
    // about why not. 
    if(bSuccess == false) 
    { 
     dwError = Marshal.GetLastWin32Error(); 
    } 
    return bSuccess; 
    } 

    public static bool SendFileToPrinter(string szPrinterName, string szFileName) 
    { 
    // Open the file. 
    FileStream fs = new FileStream(szFileName, FileMode.Open); 
    // Create a BinaryReader on the file. 
    BinaryReader br = new BinaryReader(fs); 
    // Dim an array of bytes big enough to hold the file's contents. 
    Byte []bytes = new Byte[fs.Length]; 
    bool bSuccess = false; 
    // Your unmanaged pointer. 
    IntPtr pUnmanagedBytes = new IntPtr(0); 
    int nLength; 

    nLength = Convert.ToInt32(fs.Length); 
    // Read the contents of the file into the array. 
    bytes = br.ReadBytes(nLength); 
    // Allocate some unmanaged memory for those bytes. 
    pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength); 
    // Copy the managed byte array into the unmanaged array. 
    Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength); 
    // Send the unmanaged bytes to the printer. 
    bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength); 
    // Free the unmanaged memory that you allocated earlier. 
    Marshal.FreeCoTaskMem(pUnmanagedBytes); 
    return bSuccess; 
    } 

    public static bool SendStringToPrinter(string szPrinterName, string szString) 
    { 
    IntPtr pBytes; 
    Int32 dwCount; 

    // How many characters are in the string? 
    // Fix from Nicholas Piasecki: 
    // dwCount = szString.Length; 
    dwCount = (szString.Length + 1) * Marshal.SystemMaxDBCSCharSize; 

    // Assume that the printer is expecting ANSI text, and then convert 
    // the string to ANSI text. 
    pBytes = Marshal.StringToCoTaskMemAnsi(szString); 
    // Send the converted ANSI string to the printer. 
    SendBytesToPrinter(szPrinterName, pBytes, dwCount); 
    Marshal.FreeCoTaskMem(pBytes); 
    return true; 
    } 
} 

Incluye corrección de errores de Nicholas Piasecki

Answer 2

También se puede hacer una cuota/captura de la impresora como LPT y luego puede imprimir a través del comando de tipo.

http://www.nrgsoft.com/support/activekb/questions.php?questionid=11

Answer 3

que trabajó para mí!

public partial class USB : Form 
{ 
    public USB() 
    { 
     InitializeComponent(); 
    } 


    // Structure and API declarions: 
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] 
    public class DOCINFOA 
    { 
     [MarshalAs(UnmanagedType.LPStr)] 
     public string pDocName; 
     [MarshalAs(UnmanagedType.LPStr)] 
     public string pOutputFile; 
     [MarshalAs(UnmanagedType.LPStr)] 
     public string pDataType; 
    } 
    [DllImport("winspool.Drv", EntryPoint = "OpenPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd); 

    [DllImport("winspool.Drv", EntryPoint = "ClosePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool ClosePrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint = "StartDocPrinterA", SetLastError = true, CharSet = CharSet.Ansi, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool StartDocPrinter(IntPtr hPrinter, Int32 level, [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di); 

    [DllImport("winspool.Drv", EntryPoint = "EndDocPrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool EndDocPrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint = "StartPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool StartPagePrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint = "EndPagePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool EndPagePrinter(IntPtr hPrinter); 

    [DllImport("winspool.Drv", EntryPoint = "WritePrinter", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)] 
    public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten); 

    // SendBytesToPrinter() 
    // When the function is given a printer name and an unmanaged array 
    // of bytes, the function sends those bytes to the print queue. 
    // Returns true on success, false on failure. 
    public static bool SendBytesToPrinter(string szPrinterName, IntPtr pBytes, Int32 dwCount) 
    { 
     Int32 dwError = 0, dwWritten = 0; 
     IntPtr hPrinter = new IntPtr(0); 
     DOCINFOA di = new DOCINFOA(); 
     bool bSuccess = false; // Assume failure unless you specifically succeed. 
     di.pDocName = "My C#.NET RAW Document"; 
     di.pDataType = "RAW"; 

     // Open the printer. 
     if (OpenPrinter(szPrinterName.Normalize(), out hPrinter, IntPtr.Zero)) 
     { 
      // Start a document. 
      if (StartDocPrinter(hPrinter, 1, di)) 
      { 
       // Start a page. 
       if (StartPagePrinter(hPrinter)) 
       { 
        // Write your bytes. 
        bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten); 
        EndPagePrinter(hPrinter); 
       } 
       EndDocPrinter(hPrinter); 
      } 
      ClosePrinter(hPrinter); 
     } 
     // If you did not succeed, GetLastError may give more information 
     // about why not. 
     if (bSuccess == false) 
     { 
      dwError = Marshal.GetLastWin32Error(); 
     } 
     return bSuccess; 
    } 

    public static bool SendFileToPrinter(string szPrinterName, string szFileName) 
    { 
     // Open the file. 
     FileStream fs = new FileStream(szFileName, FileMode.Open); 
     // Create a BinaryReader on the file. 
     BinaryReader br = new BinaryReader(fs); 
     // Dim an array of bytes big enough to hold the file's contents. 
     Byte[] bytes = new Byte[fs.Length]; 
     bool bSuccess = false; 
     // Your unmanaged pointer. 
     IntPtr pUnmanagedBytes = new IntPtr(0); 
     int nLength; 

     nLength = Convert.ToInt32(fs.Length); 
     // Read the contents of the file into the array. 
     bytes = br.ReadBytes(nLength); 
     // Allocate some unmanaged memory for those bytes. 
     pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength); 
     // Copy the managed byte array into the unmanaged array. 
     Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength); 
     // Send the unmanaged bytes to the printer. 
     bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength); 
     // Free the unmanaged memory that you allocated earlier. 
     Marshal.FreeCoTaskMem(pUnmanagedBytes); 
     return bSuccess; 
    } 

    public static bool SendStringToPrinter(string szPrinterName, string szString) 
    { 
     IntPtr pBytes; 
     Int32 dwCount; 

     // How many characters are in the string? 
     // Fix from Nicholas Piasecki: 
     // dwCount = szString.Length; 
     dwCount = (szString.Length + 1) * Marshal.SystemMaxDBCSCharSize; 

     // Assume that the printer is expecting ANSI text, and then convert 
     // the string to ANSI text. 
     pBytes = Marshal.StringToCoTaskMemAnsi(szString); 
     // Send the converted ANSI string to the printer. 
     SendBytesToPrinter(szPrinterName, pBytes, dwCount); 
     Marshal.FreeCoTaskMem(pBytes); 
     return true; 
    }  


    private void buttonSEND_Click(object sender, EventArgs e) 
    { 
     System.Windows.Forms.OpenFileDialog open = new System.Windows.Forms.OpenFileDialog(); 
     string dados = ""; 
     if (open.ShowDialog().Equals(DialogResult.OK)) 
     { 
      StreamReader sr = new StreamReader(open.FileName); 
      dados = sr.ReadToEnd(); 
      sr.Close(); 
     } 
     string printer = "PRINTER NAME"; 

     for (int i = 0; i < 30; i++) 
     { 
      SendStringToPrinter(printer, dados);  
     } 

    } 
}