/// <summary>
/// Returns a value indicating whether the given printer exists
/// </summary>
/// <param name="printerName">The name of the printer to check</param>
/// <returns>True if the printer already exists, false if not</returns>
public bool PrinterExists(string printerName)
{
Precondition.NotNullOrEmpty(printerName, "printerName");
var defaults = new SafeNativeMethods.PRINTER_DEFAULTS
{
DesiredAccess = SafeNativeMethods.PRINTER_ALL_ACCESS,
pDatatype = IntPtr.Zero,
pDevMode = IntPtr.Zero
};
IntPtr hPrinter;
if (SafeNativeMethods.OpenPrinter(printerName, out hPrinter, ref defaults))
{
SafeNativeMethods.ClosePrinter(hPrinter);
return(hPrinter != IntPtr.Zero);
}
return(false);
}
/// <summary>
/// Deletes the given printer from the system
/// </summary>
/// <param name="printerName">The name of the printer to delete</param>
/// <param name="portCreated">If true, the port is deleted as part of this operation</param>
public void DeletePrinter(string printerName, bool portCreated)
{
Precondition.NotNullOrEmpty(printerName, "printerName");
var pDefaults = new SafeNativeMethods.PRINTER_DEFAULTS
{
DesiredAccess = SafeNativeMethods.PRINTER_ALL_ACCESS,
pDatatype = IntPtr.Zero,
pDevMode = IntPtr.Zero
};
Exception failure = null;
/*
* Set the port to the default port before deleting the printer. Otherwise the delete may fail because the port is in use
*/
try
{
this.UpdatePort(string.Empty, DefaultPort, portCreated, printerName);
}
catch (Win32Exception)
{
}
catch (VirtualPrinterException)
{
}
for (int retries = 0; ; retries++)
{
IntPtr hPrinter;
if (SafeNativeMethods.OpenPrinter(printerName, out hPrinter, ref pDefaults))
{
try
{
/*
* Retry the deletion of the printer for a second or so, just in case
* the spooler has not had time to clean up its last print job
*/
if (!SafeNativeMethods.DeletePrinter(hPrinter))
{
if (retries < MaxPrinterDeleteAttempts)
{
Thread.Sleep(PrinterDeleteRetryDelayMs);
continue;
}
failure = new Win32Exception(Marshal.GetLastWin32Error());
}
break;
}
finally
{
SafeNativeMethods.ClosePrinter(hPrinter);
}
}
failure = new Win32Exception(Marshal.GetLastWin32Error());
break;
}
if (failure != null && this.PrinterExists(printerName))
{
throw failure;
}
}
