/// <summary>
/// Gets list of installed printer monitors
/// </summary>
/// <returns>A list of installed printer monitors</returns>
private List <String> GetInstalledMonitors()
{
uint pcbNeeded = 0;
uint pcReturned = 0;
if (PrinterMonitorInstallerPInvoke.EnumMonitors(null, 2, IntPtr.Zero, 0, ref pcbNeeded, ref pcReturned))
{
//succeeds, but must not, because buffer is zero (too small)!
throw new Exception("EnumPorts should fail!");
}
int lastWin32Error = Marshal.GetLastWin32Error();
//ERROR_INSUFFICIENT_BUFFER = 122 expected, if not -> Exception
if (lastWin32Error != 122)
{
throw new Win32Exception(lastWin32Error);
}
IntPtr pMonitors = Marshal.AllocHGlobal((int)pcbNeeded);
if (PrinterMonitorInstallerPInvoke.EnumMonitors(null, 2, pMonitors, pcbNeeded, ref pcbNeeded, ref pcReturned))
{
IntPtr currentMonitor = pMonitors;
PrinterMonitorInstallerPInvoke.MONITOR_INFO_2[] minfo = new PrinterMonitorInstallerPInvoke.MONITOR_INFO_2[pcReturned];
for (int i = 0; i < pcReturned; i++)
{
minfo[i] = (PrinterMonitorInstallerPInvoke.MONITOR_INFO_2)Marshal.PtrToStructure(currentMonitor, typeof(PrinterMonitorInstallerPInvoke.MONITOR_INFO_2));
currentMonitor = (IntPtr)(currentMonitor.ToInt32() + Marshal.SizeOf(typeof(PrinterMonitorInstallerPInvoke.MONITOR_INFO_2)));
}
Marshal.FreeHGlobal(pMonitors);
List <String> result = new List <string>();
for (int i = 0; i < pcReturned; i++)
{
result.Add(minfo[i].pName);
}
return(result);
}
throw new Win32Exception(Marshal.GetLastWin32Error());
}
