The following code works intermittently. Why is that so? Sometimes result is blank,without any error.
Imports System.DirectoryServices
Public Class Form1
Private Sub Button_Click(sender As System.Object, e As System.EventArgs) Handles Button.Click
Dim result As String = ""
Dim domainEntry As DirectoryEntry = New DirectoryEntry("WinNT://CA")'CA is the workgroup
domainEntry.Children.SchemaFilter.Add("Computer")
For Each computer As DirectoryEntry In domainEntry.Children
result = result & computer.Name & Environment.NewLine
Next
MsgBox(result)
End Sub
End class
Windows workgroups are a peer-to-peer arrangement, with no central server that controls who is on the workgroup. As such, the only way to list all the computers in the workgroup is to contact every computer in your network and check if they are part of the workgroup. That means each computer has to be powered on and connected to the same LAN.
My guess is that some computers are offline when you run that, some other reason that they cannot be contacted at the time you run it.
Old answer:
I'm not terribly familiar with using the WinNT provider, but see if you get different results with LDAP. This would find all computers on the domain (I assume "CA" is the name of your domain):
Dim ds As New DirectorySearcher(New DirectoryEntry("LDAP://CA"), "(objectClass=computer)", New String() {"cn"})
Using src As SearchResultCollection = ds.FindAll()
For Each sr As SearchResult In src
result = result & sr.Properties("cn")(0) & Environment.NewLine
Next
End Using
Related
I successfully list out remembered wifi in my windows profile using Native WI-FI from Nuget package. This is my code load list of WI-FI
Private Sub loadWifi()
listWifi.Items.Clear()
Dim wlan As WlanClient = New WlanClient()
Dim connectedSsids As List(Of String) = New List(Of String)()
For Each wlanIface As WlanClient.WlanInterface In wlan.Interfaces
For Each profileinfo As Wlan.WlanProfileInfo In wlanIface.GetProfiles()
listWifi.Items.Add(profileinfo.profileName)
Next
Next
End Sub
My intention is how can I get the selected WI-FI from combo box listWifi and connect to the network.
Then im using netsh command to connect with the network. Take from the combo box. It does not work
Private Sub ConnectTo(ByVal name As String)
Dim p = "netsh.exe"
Dim sInfo As New ProcessStartInfo(p, "wlan connect " & name)
sInfo.CreateNoWindow = True
sInfo.WindowStyle = ProcessWindowStyle.Hidden
Process.Start(sInfo)
End Sub
I made decision to use SimpleWIFI API rather than Native since it will cause my application to crash (Exception: cannot be marshaled error).
To connect the network just simply netsh wlan disconnect first and connect the network using codes above. It works but with minor error (not all available network scanned sometimes) rather than my apps to close itself unexpectedly.
I have an application done in VB.NET that listen on a specific UDP port and answer through the same port to the IP that send the packet.
It was working ok from a couple of years to the last month; now when try to answer crash due to socket error 10013.
I even try an older version that I know it was working too and get the same crash.
I try disabling Microsoft Security Essentials real time protection and Windows firewall and didn't work.
In the code I have the line
MyUdpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, True)
I have no clue about what to do, I'm lost.
Any idea how to solve this?
Edit:
Here's the code
#Region "UDP Send variables"
Dim GLOIP As IPAddress
Dim GLOINTPORT As Integer
Dim bytCommand As Byte() = New Byte() {}
#End Region
Dim MyUdpClient As New UdpClient()
Private Sub StartUdpBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StartUdpBtn.Click
If StartUdpBtn.Tag = 0 Then
' If Not UdpOpen Then
StartUdpReceiveThread(CInt(ListeningPortLbl.Text))
'End If
Else
If ThreadReceive.IsAlive Then
ThreadReceive.Abort()
MyUdpClient.Close()
PrintLog("UDP port closed")
StartUdpBtn.Tag = 0
UdpOpen = False
StartUdpBtn.Text = "Start UDP"
End If
End If
If UdpOpen Then
StartUdpBtn.Tag = 1
StartUdpBtn.Text = "Stop UDP"
Else
StartUdpBtn.Tag = 0
StartUdpBtn.Text = "Start UDP"
TimerUDP.Enabled = False
TiempoUDP.Stop()
TiempoUdpLbl.Text = "--:--:--"
End If
End Sub
Private Sub StartUdpReceiveThread(ByVal Port As Integer)
Dim UdpAlreadyOpen As Boolean = False
Try
If Not UdpOpen Then
MyUdpClient = New UdpClient(Port)
MyUdpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, True)
UdpAlreadyOpen = True
Else
Me.Invoke(Sub()
TiempoUDP.Restart()
If TimerUDP.Enabled = False Then
TimerUDP.Enabled = True
End If
End Sub)
End If
ThreadReceive = New System.Threading.Thread(AddressOf UdpReceive)
ThreadReceive.IsBackground = True
ThreadReceive.Start()
UdpOpen = True
If UdpAlreadyOpen Then
PrintLog(String.Format("UDP port {0} opened, waiting data...", Port.ToString))
End If
Catch ex As Exception
PrintErrorLog(ex.Message)
PrintErrorLog(ex.StackTrace)
End Try
End Sub
Private Sub UdpReceive()
Dim receiveBytes As [Byte]() = MyUdpClient.Receive(RemoteIpEndPoint)
DstPort = RemoteIpEndPoint.Port
IpRemota(RemoteIpEndPoint.Address.ToString)
Dim BitDet As BitArray
BitDet = New BitArray(receiveBytes)
Dim strReturnData As String = System.Text.Encoding.ASCII.GetString(receiveBytes)
If UdpOpen Then
StartUdpReceiveThread(CInt(ListeningPortLbl.Text))
End If
PrintLog("From: " & RemoteIpLbl.Text & ":" & ListeningPortLbl.Text & " - " & strReturnData)
AnswersProcessor(strReturnData)
End Sub
Private Sub UdpSend(ByVal txtMessage As String)
Dim pRet As Integer
GLOIP = IPAddress.Parse(RemoteIpLbl.Text)
'From UDP_Server3_StackOv
Using UdpSender As New System.Net.Sockets.UdpClient()
Dim RemoteEndPoint = New System.Net.IPEndPoint(0, My.Settings.UDP_Port)
UdpSender.ExclusiveAddressUse = False
UdpSender.Client.SetSocketOption(Net.Sockets.SocketOptionLevel.Socket, Net.Sockets.SocketOptionName.ReuseAddress, True)
UdpSender.Client.Bind(RemoteEndPoint)
UdpSender.Connect(GLOIP, DstPort)
bytCommand = Encoding.ASCII.GetBytes(txtMessage)
pRet = UdpSender.Send(bytCommand, bytCommand.Length)
End Using
PrintLog("No of bytes send " & pRet)
End Sub
10013 is WSAEACCES, which is documented as follows:
Permission denied.
An attempt was made to access a socket in a way forbidden by its access permissions. An example is using a broadcast address for sendto without broadcast permission being set using setsockopt(SO_BROADCAST).
Another possible reason for the WSAEACCES error is that when the bind function is called (on Windows NT 4.0 with SP4 and later), another application, service, or kernel mode driver is bound to the same address with exclusive access. Such exclusive access is a new feature of Windows NT 4.0 with SP4 and later, and is implemented by using the SO_EXCLUSIVEADDRUSE option.
In the comments you mentioned:
I tried the program on a XP x32 and works ok but on Windows 7 x32/x64 don't, even if I disable the firewall and Microsoft Security Essentials Live Protection.
Maybe it sounds almost obvious but you could try to start your program in all of the available Windows XP compatibility modes. You didn't say that you already tried this but maybe you're lucky and the problem will be "solved" by this workaround.
If the problem still exists afterwards and considering the error code of 10013, I would try or check the following things:
I know you disabled "Microsoft Security Essentials" and the Windows Firewall, but double check whether there are other security related programs/services like anti virus protection, anti malware tools etc. running. It really sounds like something is blocking your socket creation/bind.
In case your program created log output/data which allows you to see exactly when it started to fail:
Any new software installed at that time?
Were Windows Updates (maybe automatically) installed at that time? Especially security updates regarding network security?
Any other noticeable changes in your environment? What about log entries in your Windows system log?
Just as a little test to verify if the error occurs only with your UDP socket: Try to use a TCP socket instead of UDP.
Start the machine in Windows Safe Mode with network support and execute your program from there.
Run your program on another Windows 7 machine and see if the same problem occurs there. It could be a valuable starting point (in terms of localization) to know if the problem occurs only on specific versions of Windows.
Single step through your code with a debugger and carefully watch what happens. Perhaps this can reveal some additional info on what's going wrong.
Maybe some of the ideas above can help you to track down the problem a little bit more. Good luck!
So this is what I've got -
Public Shared Function GetDirectoryEntry() As DirectoryEntry
Try
Dim entryRoot As New DirectoryEntry("LDAP://RootDSE")
Dim Domain As String = DirectCast(entryRoot.Properties("defaultNamingContext")(0), String)
Dim de As New DirectoryEntry()
de.Path = "LDAP://" & Domain
de.AuthenticationType = AuthenticationTypes.Secure
Return de
Catch
Return Nothing
End Try
End Function
Protected Sub rbAddUser_Click(sender As Object, e As EventArgs) Handles rbAddUser.Click
AddMemberToGroup("LDAP://DOMAIN.local/CN=" & !DISTRIBUTIONNAME! & ",CN=Users,DC=DOMAIN,DC=local", "/CN=" & !SELECTEDUSER! & ",CN=Users,DC=DOMAIN,DC=local")
End Sub
Private Sub AddMemberToGroup(ByVal bindString As String, ByVal newMember As String)
Dim ent As DirectoryEntry = GetDirectoryEntry()
ent.Properties("member").Add(newMember)
ent.CommitChanges()
End Sub
I hope this is easy enough for people to read, anyway the group and user are selected by the users in a table and when they click the add button I want the selected users to be adding to the selected distribution list.
when it gets to the CommitChanges() I get this error
An exception of type 'System.DirectoryServices.DirectoryServicesCOMException' occurred in System.DirectoryServices.dll but was not handled in user code Additional information: An operations error occurred.Error -2147016672
This is a common issue with the Process Model application pool configuration, from the official documentation:
By using the <processModel> element, you can configure many of the security, performance, health, and reliability features of application pools on IIS 7 and later.
This issue exists as CommitChanges() requires elevated privileges, and can be fixed by setting your web-application to run under NetworkManager; this can be done in two ways:
Directly in your code, place the problem code inside this Using statement:
Using HostingEnvironment.Impersonate()
'Problem code goes here.
End Using
Via IIS Manager:
Navigate to your website's application pool;
Navigate to Advanced Settings;
Scroll down to the Process Model group;
Change Identity to NetworkService
I solved the error by passing through my user credentials
Private Sub AddMemberToGroup(ByVal bindString As String, ByVal newMember As String)
Dim ent As New GetDirectoryEntry(bindString)
ent.Properties("member").Add(newMember)
ent.Username = "DOMAIN\USERNAME"
ent.Password = "PASSWORD"
ent.CommitChanges()
End Sub
However my code still doesn't work, I just get no errors.
I am having a problem with a tool that I wrote in VB.NET running on certain XP machines. The tool runs fine and as expected on Windows 7 and XP machines that have .NET 4.0.30319.1022.
I've noticed the XP machines that I am having trouble on are those that did not have .NET 4 even on it, so I went and installed .NET 4 which puts on version .NET 4.0.30319.1.
Here is the error:
Here is the code at line 86 (86 is the For Each):
'_BIOSVer
Dim bios_query As String = "SELECT * FROM " & "Win32_BIOS"
Dim bios_searcher As New ManagementObjectSearcher(bios_query)
For Each info As ManagementObject In bios_searcher.Get()
_BIOSVer = info.Properties("BIOSVersion").Value.ToString()
Next info
I am running Windows Updates for .NET 4 Framework to see if that will fix the issue, but I was wondering if you guys might have a sense of what is happening, or if my code is just wrong.
Updates just finished, restarted. It is running off of .NET 4.0.30319.1022 but still throws that error. Must be my code then.
There are several problems, but mainly BIOSVersion is a string array. Rather than poking into that, you can just get the Name which returns the version info (so does Caption and Description). Since you are after one thing, you dont need a loop, but I left it in as a template:
Dim myver As String = ""
Using searcher As New ManagementObjectSearcher("Select Name From Win32_Bios")
For Each mo As ManagementObject In searcher .Get
' EXAMPLE
'DebugProperties(mo)
' no real need to Loop - just for illustration
For Each pd As System.Management.PropertyData In mo.Properties
' if you do SELECT * and want to find something,
' compare Pd.Name to the target property
' some things can be nothing. Such as when a property does not
' exist on older systems, so always test:
If pd.Value IsNot Nothing Then
myver = pd.Value.ToString
Exit For
End If
Next
Next
End Using
Return myver
This is a helpful WMI debug tool to display all the property names and values (the code above has the call to this commented out):
Private Shared Sub DebugProperties(mo As Management.ManagementObject)
For Each pd As PropertyData In mo.Properties
If pd.Value IsNot Nothing Then
Console.WriteLine("{0} {1}", pd.Name,
If(pd.Value IsNot Nothing,
pd.Value.ToString,
"Nothing"))
End If
Next
End Sub
BIOS Version returns a string array (for more information check this link).
Try reading the data like this
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim BIOSSearcher As New ManagementObjectSearcher("SELECT BIOSVersion FROM Win32_BIOS")
Dim BIOSVersionInfo() As String = BIOSSearcher.Get(0).Properties("BIOSVersion").Value
Dim BIOSVersion As String = ""
If Not BIOSVersionInfo Is Nothing Then
BIOSVersion = String.Join(vbCrLf, BIOSVersionInfo)
End If
MsgBox(BIOSVersion)
End Sub
So there's an application at my work that installs several Windows services to a server. As a side project, I've been asked to make a simple GUI that will list these services with a "light" (a picture box with a red or green dot) next to the name of each service. The idea is that in the event these services were to stop running, the "light" would change from green to red.
I have the GUI part built, and I can query a remote server's services, then compare it to an array of the ones I'm interested and set the "light" next to each service to green/red depending on the service state. The part I'm hung up on is how to monitor these services in real time? Currently, I just have the following code in the Form_Load event:
Dim myConnectionOptions As New System.Management.ConnectionOptions
With myConnectionOptions
.Impersonation = System.Management.ImpersonationLevel.Impersonate
.Authentication = System.Management.AuthenticationLevel.Packet
End With
Try
Dim myManagementScope As System.Management.ManagementScope
myManagementScope = New System.Management.ManagementScope("\\" & SERVERNAME & "\root\cimv2", myConnectionOptions)
myManagementScope.Connect()
Dim query As New Management.ObjectQuery("SELECT * FROM Win32_Service")
Dim searcher As New Management.ManagementObjectSearcher(myManagementScope, query)
Dim i As Integer = 0
For Each queryObj As Management.ManagementObject In searcher.Get()
For Each service As String In arrServices
If queryObj("DisplayName").Equals(service) Then
If queryObj("State").Equals("Stopped") Then
arrLights(i).Image = My.Resources.redlight
End If
i += 1
End If
Next
Next
Catch err As Management.ManagementException
MessageBox.Show("WMI query failed with the following error: " & err.Message)
Catch unauthorizedErr As System.UnauthorizedAccessException
MessageBox.Show("Authentication error: " & unauthorizedErr.Message)
End Try
Would a simple timer that executes this code repeatedly be the best approach, or is there a more elegant solution? I have a little experience in VB.NET and WMI, but none in any type of real-time monitoring activity like this.
First of all i would put it into a thread, that way even if your connection times out you dont freeze your UI, then i would use a custom wait timer not the built in one as cross threading can be a pain.
wait timer:
Public Sub Wait(ByVal wait_time As Integer)
Dim time As Date
time = Now.AddMilliseconds(wait_time)
Do While time > Now
Application.DoEvents()
Loop
End Sub
example of threading:
Private services_check As Thread
private sub form1_load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
services_check = new thread(AddressOf 'Current code in a public sub')
services_cheack.IsBackground = True
Services_check.start()
It may not be the most elegant solution but its how i would do it, as for your current code im sorry i dont know enough about remote connections to help you.