Send raw data to printer using C#

[harini19]

I have implemented the code to send raw data to printer using the below KB article.
http://support.microsoft.com/?kbid=322091

The receipt printer works for small strings but when I send large string data (250 lines), not all the information is printed correctly. Has anyone run into this issue before.

Please help !!

[RhysW]

when you say not printed correctly what do you mean? is it not being printed? being printed but in the wrong place?, being printed off the edge of the paper? the more information you give the faster you can get help!

[harini19]

I meant that not all the data is printed. Some information is missing. For eg. - If I am printing an array of 100 items, then the receipt prints first 30-40 lines then it jumps of to printing last few records.

I am using bool SendStringToPrinter( string szPrinterName, string szString ) function.

I had debugged to find if complete string is passed to the above procedure call and it is correct. How can I find if correct byte value is passed when the below function is called.

pBytes = Marshal.StringToCoTaskMemAnsi(szString);

Thanks for your help!!

[Plater]

I use raw printer all the time without any trouble, but i made a few changes.

// 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.
private static bool SendBytesToPrinter(string DocName, string szPrinterName, IntPtr pBytes, Int32 dwCount)
{
    Int32 dwWritten = 0;
    IntPtr hPrinter = new IntPtr(0);
    DOCINFOA di = new DOCINFOA();
    bool bSuccess = false; // Assume failure unless you specifically succeed.
 
    LastErrorNumber = 0;
 
    di.pDocName = DocName;// "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)
    {
        LastErrorNumber = Marshal.GetLastWin32Error();
    }
    return bSuccess;
}
public static bool SendBytesToPrinter(string DocName, string szPrinterName, byte[] data)
{
  bool retval = false;
  IntPtr pUnmanagedBytes = Marshal.AllocCoTaskMem(data.Length);//Allocate unmanaged memory
  Marshal.Copy(data, 0, pUnmanagedBytes, data.Length);//Copy bytes into unmanaged memory
  retval = SendBytesToPrinter(DocName, szPrinterName, pUnmanagedBytes, data.Length);//Send bytes to printer
  Marshal.FreeCoTaskMem(pUnmanagedBytes);// Free the allocated unmanaged memory
  return retval;
}
 

Using the sendbytes is my prefered way, but if you want a nice wrapper function for your strings:

public static bool SendASCIStringToPrinter(string DocName, string szPrinterName, string data)
{//Using ASCII encoding might be wrong, you could try UTF8 if you're not happy with ASCII
    return SendBytesToPrinter(DocName, szPrinterName, Encoding.ASCII.GetBytes(data));
}