Line Printing

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Guest

Hi
I would like to be able to print one line at a time using a network line printer, without ejecting tha page each time one line has been printed. The PrintDocument object seems to support printing at page level only. Does anyone have something to suggest here? Older applications used to send control characters to the printer in order to achieve this behavior. Does a similar technique apply here

Thanks in advance
Antonis.
 
Hi,
I would like to be able to print one line at a time using a network line
printer, without ejecting tha page each time one line has >been printed.
The PrintDocument object seems to support printing at page level only.
Does anyone have something to suggest >here? Older applications used to
send control characters to the printer in order to achieve this behavior.
Does a similar >technique apply here?
Click to expand...

Yea, you'll want to print directly to the printer, not using GDI+.

This class should work for you.

-Michael
MVP

public class RawPrinter {

#region Win32

[StructLayout(LayoutKind.Sequential)]
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, long 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 );

[DllImport("kernel32.dll", EntryPoint="GetLastError", SetLastError=false,
ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
public static extern Int32 GetLastError();

#endregion

private static bool SendBytesToPrinter(string szPrinterName, IntPtr
pBytes, Int32 dwLength) {
Int32 dwError = 0, dwWritten = 0;
IntPtr hPrinter = new IntPtr(0);
DOCINFOA di = new DOCINFOA();
bool bSuccess = false; // Assume failure unless you specifically succeed.
int MAX_DATA = 2000;

di.pDocName = "Receipt";
di.pDataType = "RAW";

while (dwLength > 0) {
// Open the printer.
if (OpenPrinter(szPrinterName, out hPrinter, 0)) {
// Start a document.
if (StartDocPrinter(hPrinter, 1, di)) {
// Start a page.
if (StartPagePrinter(hPrinter)) {
// Write your bytes.
bSuccess = WritePrinter(
hPrinter,
pBytes,
(dwLength > MAX_DATA)?MAX_DATA:dwLength,
out dwWritten);

if (!bSuccess) {
// could not print the receipt
return false;
}

pBytes = (IntPtr)(pBytes.ToInt32() + dwWritten);
dwLength -= dwWritten;
EndPagePrinter(hPrinter);
} else {
// could not start a page
return false;
}

EndDocPrinter(hPrinter);

} else {
// could not start a doc
return false;
}

ClosePrinter(hPrinter);

} else {
// could not open the printer
return false;
}

if (dwLength > 0) {
System.Threading.Thread.Sleep(10000);
}
}

// If you did not succeed, GetLastError may give more information
// about why not.
if( bSuccess == false ) {
dwError = GetLastError();
}

return bSuccess;
}


public static void SendStringToPrinter(string szPrinterName, string
szString) {
// print the stuff on a new thread
RawPrinter rp = new RawPrinter(szPrinterName, szString);
rp.Start();
}


private Thread spirit;
private string szPrinterName, szString;

private RawPrinter(string szPrinterName, string szString) {
this.szPrinterName = szPrinterName;
this.szString = szString;

spirit = new Thread(new ThreadStart(PrintOut));
spirit.IsBackground = true;
}

public void Start() {
spirit.Start();
}

private void PrintOut() {
IntPtr pBytes;
Int32 dwLength;

// How many characters are in the string?
dwLength = szString.Length;

// Convert to ANSI string and allovcate in unmanaged heap
pBytes = Marshal.StringToHGlobalAnsi(szString);

// Send the converted ANSI string to the printer.
SendBytesToPrinter(szPrinterName, pBytes, dwLength);

// free the converted string
Marshal.FreeHGlobal(pBytes);
}
}
 
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