Develop Reference

How to contentiously loop through in order to get printer Status

I have coded a simple console application that checks the status of a printer. When status of a printer changes to a "printing status" the console app simply writes out a message saying "The Printer is now Printing".
Now what i'm having difficulties with is making this program keep checking the status of printer .. I'm not so sure what loop i have to use and how i can apply it. Please see below for more information:
public static void getPrintJob()
{
string printerName = "Some Printer Name";
string query = string.Format("SELECT * from Win32_Printer WHERE Name LIKE '%{0}'", printerName);
ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
ManagementObjectCollection coll = searcher.Get();
foreach (ManagementObject printer in coll)
{
if (Convert.ToInt32(printer.Properties["PrinterStatus"].Value) == 4)
{
Console.Write("Printer is Printing");
}
What kind of loop could i put above for this program to continuously keep on checking the the printer status? and whenever the status changes to 4 (printing status on the printer i'm targeting ).

If you want this to run forever, a while loop will work:
public static void getPrintJob()
{
string printerName = "Some Printer Name";
string query = string.Format("SELECT * from Win32_Printer WHERE Name LIKE '%{0}'", printerName);
ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
while(true)
{
ManagementObjectCollection coll = searcher.Get();
var alreadyPrinting = false;
foreach (ManagementObject printer in coll)
{
if (Convert.ToInt32(printer.Properties["PrinterStatus"].Value) == 4 && !alreadyPrinting)
{
Console.Write("Printer is Printing");
alreadyPrinting = true;
}
else
{
alreadyPrinting = false;
}
}
Thread.Sleep(1000);
}
}
As RB pointed out in the comments, Thread.Sleep(1000) will pause the loop for 1 second and stop it consuming all the CPU resource.
EDIT:
updated after comments.
Added a bool to track if the printer was already printing. This stops the code writing to the console for as long as the printer is printing. Multiple printers can start and will write to the console. But only once per print job.
Moved the coll variable assignment inside the while loop.

Comparing PrintQueue to determine default print queue

I am retrieving the default print queues thanks to the help of this question. I am also able to determine the DefaultPrintQueue
But how does one properly determine what print queue in the list of print queues is equal to the DefaultPrintQueue?
I've tried:
var dq = LocalPrintServer.GetDefaultPrintQueue();
foreach(PrintQueue pq in pqcOnLocalServer)
{
if(pq.Equals(dq))
{
System.Console.WriteLine("Found default");
}
}
but the two objects obviously won't be the same. I would then assume I could compare properties of each PrintQueue with the default, but what properties should be used to determine, 100%, that the two PrintQueues are referring to the same PrintQueue?

Try and use the LocalPrintServer.DefaultPrintQueue property to get the default print queue and compare the PrintQueue.FullName. This negates the need to iterate through the LocalPrintServer PrintQueueCollection.
LocalPrintServer printServer = new LocalPrintServer(PrintSystemDesiredAccess.AdministrateServer);
PrintQueue pq = printServer.DefaultPrintQueue;
PrintQueue dq = LocalPrintServer.GetDefaultPrintQueue();
if (dq != null && pq.FullName.Equals(dq.FullName))
{
Console.WriteLine("Found default print Queue: {0}", dq.FullName);
}
If you still need to iterate through the LocalPrintServer PrintQueueCollection you can try the implementation below.
LocalPrintServer printServer = new LocalPrintServer(PrintSystemDesiredAccess.AdministrateServer);
PrintQueue dq = LocalPrintServer.GetDefaultPrintQueue();
foreach (PrintQueue pq in printServer.GetPrintQueues())
{
if (dq != null && pq.FullName.Equals(dq.FullName))
{
Console.WriteLine("Found default print Queue: {0}", dq.FullName);
}
}

This question might have done well on Expert Exchange, or Server Exchange. What I've found is that a print server will not allows printers on the server which have existing names already on the printer server. With that being said, a printer must have a unique name per server.
With that being said, a user must be careful to not only compare printer names to ensure that they are unique, but they must also compare the printer server that they are on. For example, when enumerating connected a printers. A computer could be connected to two print servers where there is a \\PRNTSRVR1\HQ_LaserJet01 and \\PRNTSRVR2\HQ_LaserJet01; so checking the connected server is important too.

Is there a way to check if a printing process was successful?

I have an application where I need to print a ticket. Each ticket must be unique. The application is windows forms and written entirely in c#. For our application we're using Samsung ML- 2525 laser monochromatic printers.
The flow is basically the following, the operator picks a product/ticket (which is unique) and then it presses a button that does 2 things:
Connects to a database and updates the product as used
Prints the ticket (this is done using System.Drawing and GDI+)
For some reason, every once in a while, the image that needs to be printed is not sent to the printer. It's a rare case, but it happens.
I tried to connect to the printer using Win32_Printer ( http://msdn.microsoft.com/en-us/library/Aa394363 ) but I can't get to get the current printer's state (online, offline, low toner, paper jam, etc). I can only check if the printer exists and that the paper size is installed correctly. I tried code similar to the following but it didn't work
private string MonitorPrintJobWmi()
{
var jobMessage = String.Empty;
var scope = new ManagementScope(ManagementPath.DefaultPath);
scope.Connect();
var selectQuery = new SelectQuery { QueryString = #"select * from Win32_PrintJob" };
var objSearcher = new ManagementObjectSearcher(scope, selectQuery);
var objCollection = objSearcher.Get();
foreach (var job in objCollection)
{
if (job != null)
{
jobMessage += String.Format("{0} \r\n", job["Name"].ToString());
jobMessage += String.Format("{0} \r\n", job["JobId"].ToString());
_jobId = Convert.ToInt32(job["JobId"]);
jobMessage += String.Format("{0} \r\n", job["JobStatus"].ToString());
jobMessage += String.Format("{0} \r\n", job["Status"].ToString());
}
}
return jobMessage;
}
I tried to get an API for the printer but I couldn't get a hold of it. By the way, the printer's software do indicate different errors in the windows toolbar.
My question is if anyone can lead me in the right direction as to how to connect to a printer and check if printing was successful.
Also, it would be helpful if someone know of some other specific printer in which I may accomplish this ie, changing hardware.
Thanks,

To get a list of print queues on the local machine, try PrintServer's GetPrintQueues method.
Once you have an instance of the PrintQueue object associated with the relevant printer, you can use it to access the printer's status (IsOffline, IsPaperOut, etc.). Also, you can use it to get a list of the jobs in the given queue (GetPrintJobInfoCollection) which then will allow you to get job-specific status information (IsInError, IsCompleted, IsBlocked, etc.).
Hope this helps!

After try to print your PrintDocument (System.Drawing.Printing), try to check status of printjobs.
First step: Initialize your printDocument.
Second step: Get your printer Name From System.Drawing.Printing.PrinterSettings.InstalledPrinters.Cast<string>();
And copy it into your printerDocument.PrinterSettings.PrinterName
Third step: Try to print and dispose.
printerDocument.Print();
printerDocument.Dispose();
Last step: Run the check in a Task (do NOT block UI thread).
Task.Run(()=>{
if (!IsPrinterOk(printerDocument.PrinterSettings.PrinterName,checkTimeInMillisec))
{
// failed printing, do something...
}
});
Here is the implementation:
private bool IsPrinterOk(string name,int checkTimeInMillisec)
{
System.Collections.IList value = null;
do
{
//checkTimeInMillisec should be between 2000 and 5000
System.Threading.Thread.Sleep(checkTimeInMillisec);
// or use Timer with Threading.Monitor instead of thread sleep
using (System.Management.ManagementObjectSearcher searcher = new System.Management.ManagementObjectSearcher("SELECT * FROM Win32_PrintJob WHERE Name like '%" + name + "%'"))
{
value = null;
if (searcher.Get().Count == 0) // Number of pending document.
return true; // return because we haven't got any pending document.
else
{
foreach (System.Management.ManagementObject printer in searcher.Get())
{
value = printer.Properties.Cast<System.Management.PropertyData>().Where(p => p.Name.Equals("Status")).Select(p => p.Value).ToList();
break;
}
}
}
}
while (value.Contains("Printing") || value.Contains("UNKNOWN") || value.Contains("OK"));
return value.Contains("Error") ? false : true;
}
Good luck.

Is there a .NET way to enumerate all available network printers?

Is there a straightforward way to enumerate all visible network printers in .NET? Currently, I'm showing the PrintDialog to allow the user to select a printer. The problem with that is, local printers are displayed as well (along with XPS Document Writer and the like). If I can enumerate network printers myself, I can show a custom dialog with just those printers.
Thanks!!

Get the default printer from LocalPrintServer.DefaultPrintQueue
Get the installed printers (from user's perspective) from PrinterSettings.InstalledPrinters
Enumerate through the list:
Any printer beginning with \\ is a network printer - so get the queue with new PrintServer("\\UNCPATH").GetPrintQueue("QueueName")
Any printer not beginning with \\ is a local printer so get it with LocalPrintServer.GetQueue("Name")
You can see which is default by comparing FullName property.
Note: a network printer can be the default printer from LocalPrintServer.DefaultPrintQueue, but not appear in LocalPrintServer.GetPrintQueues()
// get available printers
LocalPrintServer printServer = new LocalPrintServer();
PrintQueue defaultPrintQueue = printServer.DefaultPrintQueue;
// get all printers installed (from the users perspective)he t
var printerNames = PrinterSettings.InstalledPrinters;
var availablePrinters = printerNames.Cast<string>().Select(printerName =>
{
var match = Regex.Match(printerName, #"(?<machine>\\\\.*?)\\(?<queue>.*)");
PrintQueue queue;
if (match.Success)
{
queue = new PrintServer(match.Groups["machine"].Value).GetPrintQueue(match.Groups["queue"].Value);
}
else
{
queue = printServer.GetPrintQueue(printerName);
}
var capabilities = queue.GetPrintCapabilities();
return new AvailablePrinterInfo()
{
Name = printerName,
Default = queue.FullName == defaultPrintQueue.FullName,
Duplex = capabilities.DuplexingCapability.Contains(Duplexing.TwoSidedLongEdge),
Color = capabilities.OutputColorCapability.Contains(OutputColor.Color)
};
}).ToArray();
DefaultPrinter = AvailablePrinters.SingleOrDefault(x => x.Default);

using the new System.Printing API
using (var printServer = new PrintServer(string.Format(#"\\{0}", PrinterServerName)))
{
foreach (var queue in printServer.GetPrintQueues())
{
if (!queue.IsShared)
{
continue;
}
Debug.WriteLine(queue.Name);
}
}

found this code here
private void btnGetPrinters_Click(object sender, EventArgs e)
{
// Use the ObjectQuery to get the list of configured printers
System.Management.ObjectQuery oquery =
new System.Management.ObjectQuery("SELECT * FROM Win32_Printer");
System.Management.ManagementObjectSearcher mosearcher =
new System.Management.ManagementObjectSearcher(oquery);
System.Management.ManagementObjectCollection moc = mosearcher.Get();
foreach (ManagementObject mo in moc)
{
System.Management.PropertyDataCollection pdc = mo.Properties;
foreach (System.Management.PropertyData pd in pdc)
{
if ((bool)mo["Network"])
{
cmbPrinters.Items.Add(mo[pd.Name]);
}
}
}
}
Update:
"This API function can enumerate all network resources, including servers, workstations, printers, shares, remote directories etc."
http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=741&lngWId=10

PrinterSettiings.InstalledPrinters should give you the collection you want

In another post(https://stackoverflow.com/a/30758129/6513653) relationed to this one, Scott Chamberlain said "I do not believe there is anything in .NET that can do this, you will need to make a native call". After to try all the possible .NET resource, I think he is right.
So, I started to investigate how ADD PRINTER dialog does its search. Using Wireshark, I found out that ADD PRINTER send at least two types of packages to all hosts in local network: two http/xml request to 3911 port and three SNMP requests.
The first SNMP request is a get-next 1.3.6.1.2.1.43, which is Printer-MIB. The second one, is a get 1.3.6.1.4.1.2699.1.2.1.2.1.1.3 which is pmPrinterIEEE1284DeviceId of PRINTER-PORT-MONITOR-MIB. This is the most interesting because is where ADD PRINTER takes printer name. The third is a get 1.3.6.1.2.1.1.1.0, which is sysDescr of SNMP MIB-2 System.
I do believe that the second SNMP request is enough to find most of network printers in local network, so I did this code. It works for Windows Form Application and it depends on SnmpSharpNet.
Edit: I'm using ARP Ping instead normal Ping to search active hosts in network. Link for an example project: ListNetworks C# Project

Note that if you're working over RDP it seems to complicate this because it looks like it just exports everything on the host as a local printer.
Which is then a problem if you're expecting it to work the same way when not on RDP.

How to get Printer Info in .NET?

In the standard PrintDialog there are four values associated with a selected printer: Status, Type, Where, and Comment.
If I know a printer's name, how can I get these values in C# 2.0?

As dowski suggested, you could use WMI to get printer properties. The following code displays all properties for a given printer name. Among them you will find: PrinterStatus, Comment, Location, DriverName, PortName, etc.
using System.Management;
...
string printerName = "YourPrinterName";
string query = string.Format("SELECT * from Win32_Printer WHERE Name LIKE '%{0}'", printerName);
using (ManagementObjectSearcher searcher = new ManagementObjectSearcher(query))
using (ManagementObjectCollection coll = searcher.Get())
{
try
{
foreach (ManagementObject printer in coll)
{
foreach (PropertyData property in printer.Properties)
{
Console.WriteLine(string.Format("{0}: {1}", property.Name, property.Value));
}
}
}
catch (ManagementException ex)
{
Console.WriteLine(ex.Message);
}
}

This should work.
using System.Drawing.Printing;
...
PrinterSettings ps = new PrinterSettings();
ps.PrinterName = "The printer name"; // Load the appropriate printer's setting
After that, the various properties of PrinterSettings can be read.
Note that ps.isValid() can see if the printer actually exists.
Edit: One additional comment. Microsoft recommends you use a PrintDocument and modify its PrinterSettings rather than creating a PrinterSettings directly.

Look at PrinterSettings.InstalledPrinters

Just for reference, here is a list of all the available properties for a printer ManagementObject.
usage: printer.Properties["PropName"].Value

It's been a long time since I've worked in a Windows environment, but I would suggest that you look at using WMI.

Please notice that the article that dowski and Panos was reffering to (MSDN Win32_Printer) can be a little misleading.
I'm referring the first value of most of the arrays. some begins with 1 and some begins with 0.
for example, "ExtendedPrinterStatus" first value in table is 1, therefore, your array should be something like this:
string[] arrExtendedPrinterStatus = {
"","Other", "Unknown", "Idle", "Printing", "Warming Up",
"Stopped Printing", "Offline", "Paused", "Error", "Busy",
"Not Available", "Waiting", "Processing", "Initialization",
"Power Save", "Pending Deletion", "I/O Active", "Manual Feed"
};
and on the other hand, "ErrorState" first value in table is 0, therefore, your array should be something like this:
string[] arrErrorState = {
"Unknown", "Other", "No Error", "Low Paper", "No Paper", "Low Toner",
"No Toner", "Door Open", "Jammed", "Offline", "Service Requested",
"Output Bin Full"
};
BTW,
"PrinterState" is obsolete, but you can use "PrinterStatus".

I know it's an old posting, but nowadays the easier/quicker option is to use the enhanced printing services offered by the WPF framework (usable by non-WPF apps).
http://msdn.microsoft.com/en-us/library/System.Printing(v=vs.110).aspx
An example to retrieve the status of the printer queue and first job..
var queue = new LocalPrintServer().GetPrintQueue("Printer Name");
var queueStatus = queue.QueueStatus;
var jobStatus = queue.GetPrintJobInfoCollection().FirstOrDefault().JobStatus

As an alternative to WMI you can get fast accurate results by tapping in to WinSpool.drv (i.e. Windows API) - you can get all the details on the interfaces, structs & constants from pinvoke.net, or I've put the code together at http://delradiesdev.blogspot.com/2012/02/accessing-printer-status-using-winspool.html