Develop Reference

Retrieve LoggedOnUsers on Remote Machine

I'm building a C# application to monitor server and workstation workloads with WMI and WQL queries. I'm using WMI because it seems to be faster in comparison to powershell queries. My hardship starts when I try to retrieve logged on users on a remote machine. I figured I need to use the Win32_LoggedOnUser class. I have tried the following queries:
#"SELECT * FROM Win32_LoggedOnUser"
#"SELECT Antecedent FROM Win32_LoggedOnUser"
What I'm used to is to retrieve the desired value like this:
var cims = connection.getCimInstances(this, queryUser);
if (cims != null)
{
foreach (CimInstance cim in cims)
{
Komponenten.User user = new Komponenten.User();
user.Name = Convert.ToString(cim.CimInstanceProperties["Name"].Value);
users.Add(user);
}
}
where queryUser is one of the strings from above.
In both cases, I get a Win32_Account object in return, which seems to suggest - and the debugger seems to confirm - that I should use CimInstanceProperties["Name"].Value on the returned Win32_Account class again. But that's not working at all. Any ideas on how to get access to the CimInstanceProperties of a Win32_Account stored in a CimInstanceProperity ? I can't find anything on the respective Windows reference page (https://learn.microsoft.com/en-us/windows/win32/cimwin32prov/win32-loggedonuser) nor during my extensive google-search.
Thanks!

I ended up using the ManagementObject-Class and Regex to find the usernames after converting the Antecedent - Object to a string:
var users = new List<Komponenten.User>();
var searcher = this.connection.makeQuery(this, "SELECT * FROM Win32_LoggedOnUser");
if (searcher != null)
{
foreach (ManagementObject queryObj in searcher.Get())
{
Komponenten.User user = new Komponenten.User();
var win32_account = queryObj["Antecedent"].ToString();
string stripped = Regex.Replace(win32_account, "[^a-zA-Z=]+", "", RegexOptions.Compiled);
int end = stripped.LastIndexOf("=");
user.Name = stripped.Substring(end+1);
users.Add(user);
}
this.users = users;
An alternative which takes the LogonSession into account is:
var users = new List<Komponenten.User>();
var searcher = this.connection.makeQuery(this, "SELECT LogonId FROM Win32_LogonSession Where LogonType=2");
var Scope = this.connection.getScope(this, this.connection.getConnection());
if (searcher != null)
{
foreach (ManagementObject queryObj in searcher.Get())
{
ObjectQuery LQuery = new ObjectQuery("Associators of {Win32_LogonSession.LogonId=" + queryObj["LogonId"] + "} Where AssocClass=Win32_LoggedOnUser Role=Dependent");
ManagementObjectSearcher LSearcher = new ManagementObjectSearcher(Scope, LQuery);
foreach (ManagementObject LWmiObject in LSearcher.Get())
{
Komponenten.User user = new Komponenten.User();
user.Name = Convert.ToString(LWmiObject["Name"]);
users.Add(user);
}
}
this.users = users;
}
where this.connection.getConnection is a ConnectionsOption object depending on your respective domain and account data

C# Trying to get the printer status when it is offline

I need to get the printer status when it is offline, below is how I am getting the status;
// Set management scope
ManagementScope scope = new ManagementScope(#"\root\cimv2");
scope.Connect();
// Select Printers from WMI Object Collections
ManagementObjectSearcher searcher = new
ManagementObjectSearcher("SELECT * FROM Win32_Printer");
string printerName = "";
foreach (ManagementObject printer in searcher.Get())
{
printerName = printer["Name"].ToString();
if (printerName.Equals(#"TEC B-EV4-T"))
{
//Console.WriteLine("Printer = " + printer["Name"]);
if (printer.Properties["PrinterStatus"].Value.ToString() == "7")
{
// printer is offline by user
MessageBox.Show("TEC B-EV4-T is offline");
}
else
{
// printer is not offline
//Check API first then print
ReportDocument cryRpt = new ReportDocument();
cryRpt.Load(Environment.CurrentDirectory + "\\Report.rpt");
dialog.PrintQueue = new PrintQueue(new PrintServer(), "TEC B-EV4-T");
//to the data table here
//To data table
DataTable dt = ToDataTable(lotinstruct);
cryRpt.SetDataSource(dt);
cryRpt.PrintToPrinter(1, true, 0, 0);
//}
MessageBox.Show("Already save result please check label!");
}
}
}
The problem is here if (printer.Properties["PrinterStatus"].Value.ToString() == "7") it seems like the printer status is always 3 when I debug (printer status 3 means that it is idle 7 means that it is offline). Is there any way to find out if the printer TEC B-EV4-T is offline?

You can refer PrintQueue in built in .Net framework to check printer status. There are many properties in it to check different status:
string printerName = "TEC B-EV4-T";
var server = new LocalPrintServer();
PrintQueue queue = server.GetPrintQueue(printerName , Array.Empty<string>());
bool isOffline = queue.IsOffline;
bool isBusy = queue.IsBusy;

Don't use printer["PrinterStatus"]. You have to use printer["WorkOffline"] like below:
bool IsOffline = false;
ManagementObjectSearcher searcher = new
ManagementObjectSearcher("SELECT * FROM Win32_Printer where Name='" + YourPrinter + "'");
foreach(ManagementObject printer in searcher.Get())
{
IsOffline = (bool)printer["WorkOffline"];
}
if (IsOffline)
{
...
}

WMI does not return expected service, ServiceController identifies OK

I'm trying to identify if a certain service on a remote PC is running or not and identify its start up type.
Using ServiceController I can successfully see the expected service on the remote machine but when switching to use WMI to drill deeper this service no longer appears.
Heres my code:
public static void Main()
{
var ctl = ServiceController.GetServices("[Name]");
List<string> namelist = new List<string>();
foreach (var x in ctl)
{
if (x.DisplayName == "NHS Card Checker")
{
Console.WriteLine(string.Format("NHS Card checker found on MPC - Status: {0}", x.Status));
ConnectionOptions options = new ConnectionOptions();
options.Impersonation = System.Management.ImpersonationLevel.Impersonate;
ManagementScope scope = new ManagementScope(#"[Name]\root\cimv2");
scope.Connect();
string wmiQuery = string.Format("Select * from Win32_Service", x.DisplayName);
ManagementObjectSearcher wmi = new ManagementObjectSearcher(wmiQuery);
ManagementObjectCollection coll = wmi.Get();
foreach (var service in coll)
{
Console.WriteLine(string.Format("{0} - {1}", service["Name"].ToString(), service["StartMode"].ToString()) );
}
}
}
Console.ReadKey();
}

Looks good for the most part. I would lead the scope with "\\" before your machine name. Also, if you are just looking for one specific service, add a WHERE clause to your query.
public static void Main()
{
string MachineName = "[Name]";
var ctl = ServiceController.GetServices(MachineName);
List<string> namelist = new List<string>();
foreach (var x in ctl)
{
if (x.DisplayName == "NHS Card Checker")
{
Console.WriteLine(string.Format("NHS Card checker found on MPC - Status: {0}", x.Status));
ConnectionOptions options = new ConnectionOptions();
options.Impersonation = System.Management.ImpersonationLevel.Impersonate;
ManagementScope scope = new ManagementScope(String.Format(#"\\{0}\root\cimv2", MachineName));
scope.Connect();
string wmiQuery = string.Format("Select * from Win32_Service WHERE DisplayName='{0}'" , x.DisplayName);
ManagementObjectSearcher wmi = new ManagementObjectSearcher(wmiQuery);
ManagementObjectCollection coll = wmi.Get();
foreach (var service in coll)
{
Console.WriteLine(string.Format("{0} - {1}", service["Name"].ToString(), service["StartMode"].ToString()));
}
}
}
Console.ReadKey();
}
or maybe simplify it to only use WMI like...
string MachineName = "[Name]";
string TargetService = "NHS Card Checker";
{
ConnectionOptions options = new ConnectionOptions();
options.Impersonation = System.Management.ImpersonationLevel.Impersonate;
ManagementScope scope = new ManagementScope(String.Format(#"\\{0}\root\cimv2", MachineName));
scope.Connect();
string wmiQuery = String.Format("Select * from Win32_Service WHERE DisplayName='{0}'", TargetService);
ManagementObjectSearcher wmi = new ManagementObjectSearcher(wmiQuery);
ManagementObjectCollection coll = wmi.Get();
if (coll.Count > 0)
{
foreach (var service in coll)
{
Console.WriteLine(string.Format("NHS Card checker found on MPC - Status: {0}", service["Status"].ToString()));
Console.WriteLine(string.Format("{0} - {1}", service["Name"].ToString(), service["StartMode"].ToString()));
}
}
else
{
Console.WriteLine(string.Format("{0} Service was not found", TargetService));
}
}
}
Also, in newer implementations of C# you can use an easier variance of string interpolation. Instead of...
string.format("{0} is your value", VariableName");
you can use
$"{VariableName} is your value";

Listing network printers

Trying to run the following (found here http://www.encodedna.com/2013/04/show-printers-using-wmi.htm ) to get a list of network printers but it only returns printers added to my machine
System.Management.ManagementScope objMS = new System.Management.ManagementScope(ManagementPath.DefaultPath);
objMS.Connect();
SelectQuery objQuery = new SelectQuery("SELECT * FROM Win32_Printer");
ManagementObjectSearcher objMOS = new ManagementObjectSearcher(objMS, objQuery);
System.Management.ManagementObjectCollection objMOC = objMOS.Get();
foreach (ManagementObject Printers in objMOC)
{
if (Convert.ToBoolean(Printers["Local"])) // LOCAL PRINTERS.
{
Console.WriteLine("Local :- " + Printers["Name"]);
}
if (Convert.ToBoolean(Printers["Network"])) // ALL NETWORK PRINTERS.
{
Console.WriteLine("Network :- " + Printers["Name"]);
}
}
I can view/add network printers in control panel. Just curious why it isn't showing them. Any thoughts?
Thanks!

Try:
foreach (string printerString in PrinterSettings.InstalledPrinters)
{
// do something
}

How to get hard drive unique serial number in C#

I develop an activation for a system. to generate request code, I used HDD ID, Bios ID and Processor ID. I used following code to get hard disk ID.
private string getHardDiskID()
{
string hddID = null;
ManagementClass mc = new ManagementClass("Win32_LogicalDisk");
ManagementObjectCollection moc = mc.GetInstances();
foreach (ManagementObject strt in moc)
{
hddID += Convert.ToString(strt["VolumeSerialNumber"]);
}
return hddID.Trim().ToString();
}
But if I plug a removable disk, That ID value is changed. How to get the UNIQUE Serial Number of the hard drive...?
Thanks in advance..

You can try from this source:
As said in the source, a better solution is to get the Hard Drive Serial Number given by the Manufacturer. This value won't change even if you format your Hard Drive.
searcher = new
ManagementObjectSearcher("SELECT * FROM Win32_PhysicalMedia");
int i = 0;
foreach(ManagementObject wmi_HD in searcher.Get())
{
// get the hard drive from collection
// using index
HardDrive hd = (HardDrive)hdCollection[i];
// get the hardware serial no.
if (wmi_HD["SerialNumber"] == null)
hd.SerialNo = "None";
else
hd.SerialNo = wmi_HD["SerialNumber"].ToString();
++i;
}

ManagementObjectSearcher searcher;
searcher = new ManagementObjectSearcher("SELECT * FROM Win32_DiskDrive");
string serial_number="";
foreach (ManagementObject wmi_HD in searcher.Get())
{
serial_number = wmi_HD["SerialNumber"].ToString();
}
MessageBox.Show(serial_number);

Check below code to get HDD Serial
ManagementObjectSearcher objSearcher = new
ManagementObjectSearcher("SELECT * FROM Win32_DiskDrive");
objSearcher = new
ManagementObjectSearcher("SELECT * FROM Win32_PhysicalMedia");
int i = 0;
foreach(ManagementObject wmi_HD in objSearcher.Get())
{
// get the hard drive from collection
// using index
HardDrive hd = (HardDrive)hdCollection[i];
// get the hardware serial no.
if (wmi_HD["SerialNumber"] == null)
hd.SerialNo = "None";
else
hd.SerialNo = wmi_HD["SerialNumber"].ToString();
++i;
}
Also You can type "wbemtest" in windows run. WBEMTEST is tool which
helps in running WQL queries.