/// <summary>
/// Creates a new instance of <see cref="RawPrinterAccess" />.
/// </summary>
/// <param name="printerDevice"> The printer device. </param>
/// <exception cref="ArgumentNullException"> <paramref name="printerDevice" /> is null. </exception>
public RawPrinterAccess(PrinterDevice printerDevice)
{
if (printerDevice == null)
{
throw new ArgumentNullException(nameof(printerDevice));
}
this.PrinterDevice = printerDevice;
this.PrinterHandle = IntPtr.Zero;
}
public static PrinterDevice[] GetPrinters(PrinterTypes printerTypes)
{
PrinterEnumFlags flags = 0;
if ((printerTypes & PrinterTypes.Local) == PrinterTypes.Local)
{
flags |= PrinterEnumFlags.PRINTER_ENUM_LOCAL;
}
if ((printerTypes & PrinterTypes.Remote) == PrinterTypes.Remote)
{
flags |= PrinterEnumFlags.PRINTER_ENUM_REMOTE;
}
uint cbNeeded = 0;
uint cReturned = 0;
if (PrinterDevice.EnumPrinters((uint)flags, null, 2, IntPtr.Zero, 0, ref cbNeeded, ref cReturned))
{
if (cbNeeded == 0)
{
return(new PrinterDevice[0]);
}
}
int errorCode = WindowsApi.GetLastErrorCode();
if (errorCode == (int)WindowsError.ErrorInsufficientBuffer)
{
IntPtr pAddr = IntPtr.Zero;
try
{
pAddr = Marshal.AllocHGlobal((int)cbNeeded);
if (PrinterDevice.EnumPrinters((uint)flags, null, 2, pAddr, cbNeeded, ref cbNeeded, ref cReturned))
{
PRINTER_INFO_2[] printerInfo = new PRINTER_INFO_2[cReturned];
long address = pAddr.ToInt64();
long addressIncrement = Marshal.SizeOf(typeof(PRINTER_INFO_2));
for (int i1 = 0; i1 < cReturned; i1++)
{
printerInfo[i1] =
(PRINTER_INFO_2)Marshal.PtrToStructure(new IntPtr(address), typeof(PRINTER_INFO_2));
address += addressIncrement;
}
return((from x in printerInfo
select new PrinterDevice(x)).ToArray());
}
errorCode = WindowsApi.GetLastErrorCode();
}
finally
{
if (pAddr != IntPtr.Zero)
{
Marshal.FreeHGlobal(pAddr);
}
}
}
string errorMessage = WindowsApi.GetErrorMessage(errorCode);
throw new Win32Exception(errorCode, errorMessage);
}
