I get the feeling this is something really simple, but I've tried I don't know how many permutations of vbNewLine, Environment.NewLine, sMessage & vbNewLine (or Environment.Newline) I've tried, or how many pages on this site, or through Google I've looked at but nothing has worked.
I even tried getting help from a VB.Net discord channel I'm a part of and they suggested to do the same things that I've done and the procedure is still writing each new log entry at the end of the previous one in a continuous string. My writer is below. Am I missing something simple?
Edit: The code that worked is below in case anyone else comes along with the same issue. If you want to see the original code it's in the edit log.
Option Explicit On
Imports System.IO
Public Class WriteroLog
Public Shared Sub LogPrint(sMessage As String)
Dim AppPath As String = My.Application.Info.DirectoryPath
If File.Exists($"{AppPath}\Log.txt") = True Then
Try
Using objWriter As StreamWriter = File.AppendText($"{AppPath}\Log.Txt")
objWriter.WriteLine($"{Format(Now, "dd-MMM-yyyy HH:mm:ss")} – {sMessage}")
objWriter.Close()
End Using
Catch ex As Exception
MsgBox(ex)
Return
End Try
Else
Try
Using objWriter As StreamWriter = File.CreateText($"{AppPath}\Log.Txt")
objWriter.WriteLine($"{Format(Now, "dd-MMM-yyyy HH:mm:ss")} – {sMessage}")
objWriter.Close()
End Using
Catch ex As Exception
MsgBox(ex)
Return
End Try
End If
End Sub
End Class
The File.AppendText() method creates a new StreamWriter that is then used to append Text to the specified File.
Note, reading the Docs about this method, that you don't need to verify whether the File already exists: if it doesn't, the File is automatically created.
As a side note, when creating a Path, it's a good thing to use the Path.Combine method: it can prevent errors in the path definition and handles platform-specific formats.
Your code could be simplified as follows:
Public Shared Sub LogPrint(sMessage As String)
Dim filePath As String = Path.Combine(Application.StartupPath, "Log.Txt")
Try
Using writer As StreamWriter = File.AppendText(filePath)
writer.WriteLine($"{Date.Now.ToString("dd-MMM-yyyy HH:mm:ss")} – {sMessage}")
End Using
Catch ex As IOException
MsgBox(ex)
End Try
End Sub
The File.CreateText does not assign result to "objWrite", should be:
objWriter = File.CreateText($"{AppPath}\Log.Txt")
Not really sure if this is the root of your problem, but it is an issue.
In essences, your logic is re-opening or creating the stream "objWriter" for every call to this method. I would recommend you initialize "objWriter" to Nothing and only define if it is Nothing.
Set to Nothing as below.
Shared objWriter As IO.StreamWriter = Nothing
Then add check for Nothing in logic.
Hi I am currently working on a project on visual Basic 2010, what i am stuck on now is updating my MS Access database triggered by a button click.
I already have the connection and data adapter established and i generated a data set for the data adapter, and i have used the data set. what i am trying to do is read from a data grid view entries the user have typed in and save these changes to the data set, and finally save the dataset back into the database using the oledbdataadapter.update(dataset) command. I tried everything and i have been stuck for a while, there are no errors in the code and I can see the changes made to the dataset are successful and i can view them (i am getting the "update successful" at the end of the try so i am sure the code is executing till then and not going to exception), but i simply don't see the changes in the database.
below is the code, i will appreciate any help you can offer thank you.
For j As Integer = 6 To DataGridView1.Rows.Count
Try
Dim s As String = DataGridView1.Rows(j).Cells(0).Value
Dim Quantaties As Integer = DataGridView1.Rows(j).Cells(3).Value
For i As Integer = 0 To DataSet21.Tables("Stock").Rows.Count
Dim foundRow As DataRow = DataSet21.Tables("Stock").Rows.Find(i)
If foundRow IsNot Nothing Then
If foundRow(1) = s Then
DataSet21.Tables("Stock").Rows(i).Item(7) = Quantaties
DataSet21.AcceptChanges()
Try
Dim builder As New OleDbCommandBuilder(OleDbDataAdapter1)
Me.Validate()
OleDbDataAdapter1.UpdateCommand = builder.GetUpdateCommand()
OleDbDataAdapter1.Update(DataSet21.Stock)
DataSet21.AcceptChanges()
MsgBox("Update successful")
Catch ex As Exception
MsgBox("Update failed")
End Try
End If
End If
Next
BindingSource1.EndEdit()
Catch ex As Exception
End Try
Next
thank you for your reply.
I guess both ways work OleDbDataAdapter1.Update(DataSet21.Stock) and OleDbDataAdapter1.Update("DataSet21"), because i figured out what was wrong with my code. the problem was in the DataSet21.AcceptChanges() i should not have placed it before the OleDbDataAdapter1.Update(DataSet21.Stock).
the OleDbDataAdapter.update() saves changes done in the dataset to the database and the dataset.acceptchanges() makes the dataset save the changes done to it making it seem that it doesn't have changes in it anymore. so the OleDbDataAdapter.update() was not executing since the dataset didn't have changes done to it because of the dataset.acceptchanges()
so what i did was remove dataset.acceptchanges() and it finally worked. my code looks like this now.
For j As Integer = 6 To DataGridView1.Rows.Count
Try
Dim s As String = DataGridView1.Rows(j).Cells(0).Value
Dim Quantaties As Integer = DataGridView1.Rows(j).Cells(3).Value
For i As Integer = 0 To DataSet21.Tables("Stock").Rows.Count
Dim foundRow As DataRow = DataSet21.Tables("Stock").Rows.Find(i)
If foundRow IsNot Nothing Then
If foundRow(1) = s Then
DataSet21.Tables("Stock").Rows(foundRow(0) - 2).Item(7) = Quantaties
Try
BindingSource1.EndEdit()
OleDbDataAdapter1.Update(DataSet21.Stock)
MsgBox("Update successful")
Catch ex As Exception
MsgBox("Update failed")
End Try
End If
End If
Next
Catch ex As Exception
End Try
Next
i am trying to create a new instance of a form if its not allready been created the only problem is is that the instance creation is inside a thread.
Private Sub doRead(ByVal ar As System.IAsyncResult)
Dim totalRead As Integer
Try
totalRead = client.GetStream.EndRead(ar) 'Ends the reading and returns the number of bytes read.
Catch ex As Exception
'The underlying socket have probably been closed OR an error has occured whilst trying to access it, either way, this is where you should remove close all eventuall connections
'to this client and remove it from the list of connected clients.
End Try
If totalRead > 0 Then
'the readBuffer array will contain everything read from the client.
Dim receivedString As String = System.Text.Encoding.UTF8.GetString(readBuffer, 0, totalRead)
messageReceived(receivedString)
End If
Try
client.GetStream.BeginRead(readBuffer, 0, BYTES_TO_READ, AddressOf doRead, Nothing) 'Begin the reading again.
Catch ex As Exception
'The underlying socket have probably been closed OR an error has occured whilst trying to access it, either way, this is where you should remove close all eventuall connections
'to this client and remove it from the list of connected clients.
MessageBox.Show(ex.ToString)
End Try
End Sub
The problem lies when the form is created on the line .showDialog() it stops here untill the application is closed. ive tryed using .show() but then the new "Convo window just hangs"
Private Sub messageReceived(ByVal message As String)
Dim data() As String = message.Split("|"c)
Select Case data(0)
Case "MESSAGE"
Dim chatDialog As New RichTextBox
Try
If conversations.ContainsKey(data(1)) Then
Dim convoWindow As ChatWindow
convoWindow = New ChatWindow
convoWindow = conversations.Item(data(1))
chatDialog = convoWindow.RichTextBox1
Else
Try
Dim convoWindow As New ChatWindow()
conversations.Add(data(1), convoWindow)
convoWindow = conversations.Item(data(1))
convoWindow.ShowDialog()
chatDialog = convoWindow.RichTextBox1
AppendTextChatWindows(data(2), chatDialog)
Thanks
Houlahan
I get this error at the Commit of a transaction in a desktop application:
This OleDbTransaction has completed; it is no longer usable.
Other posts I have seen with similar error suggests this can occur if it takes a long time, or contains large amounts of data. This is not the case here. Logging tells me it takes 140 ms from Begin to Commit and about 10 commands executed inside the transaction.
It is using an Oracle database.
This class is a simplified version of my database class:
Class MyDatabase
Private mConnection AS OleDbConnection
Private mTransaction AS OleDbTransaction
Function Value(ByVal piSql As String) As Integer
Try
Dim lCommand As OleDbCommand
lCommand = New OleDbCommand(piSql, mConnection)
If mTransaction IsNot Nothing Then
lCommand.Transaction = mTransaction
End If
Dim lValue = lCommand.ExecuteScalar()
If Not lValue Is Nothing Then
WriteLog(lValue.ToString(), 3, "Value Returned")
Return lValue.ToString()
Else
WriteLog("<null>", 3, "Value Returned (null)")
Return ""
End If
Catch ex As Exception
WriteLog(ex.Message)
End Try
End Function
Function ExecuteSql(ByVal piSql As String) As Integer
Try
Dim lCommand As OleDbCommand
lCommand = New OleDbCommand(piSql, mConnection)
If mTransaction IsNot Nothing Then
lCommand.Transaction = mTransaction
End If
Return lCommand.ExecuteNonQuery()
Catch ex As Exception
WriteLog(ex.Message)
End Try
End Function
Public Sub BeginTransaction()
Try
mTransaction = mConnection.BeginTransaction()
Catch ex As Exception
WriteLog(ex.Message)
End Try
End Sub
Public Sub Commit()
If Not mTransaction Is Nothing Then
Try
mTransaction.Commit()
Catch ex As Exception
WriteLog(ex.Message)
End Try
mTransaction.Dispose()
mTransaction = Nothing
End If
End Sub
Public Sub Rollback()
If Not mTransaction Is Nothing Then
Try
mTransaction.Rollback()
Catch ex As Exception
WriteLog(ex.Message)
End Try
mTransaction.Dispose()
mTransaction = Nothing
End If
End Sub
End Class
Calling code (simplified):
mDatabase.BeginTransaction()
mOrderId = mDatabase.Value("select max(order_id) from ler_order")
mDatabase.ExecuteSql("insert into ler_order (order_id,status,message,plotter,reference,paper_size,orientation,plot_scale,format,usr,email,no_of_copies,date_time,uservar1,uservar2,uservar3,ell,nll,eur,nur,coord_type,graveforespoergselanmodningid,graveforespoergselnr,oprettetdato,aendretdato,graveartnavn,andengraveart,lek_virksomhed,lek_navn,lek_adresse,lek_postnr,lek_postdistrikt,lek_land,lek_telefon,lek_mobiltelefon,lek_telefax,lek_email,ga_navn,ga_adresse,ga_postnr,ga_postdistrikt,ga_land,ga_telefon,ga_mobiltelefon,ga_telefax,ga_email,gak_id,gak_virksomhed,gak_navn,gak_adresse,gak_postnr,gak_postdistrikt,gak_land,gak_telefon,gak_mobiltelefon,gak_telefax,gak_email,emailafsendt,konverteringsstatus) values (101633,0,null,'LER','10d6d8bc-b9b2-44bb-84bf-ceca42a0970a',null,0,0,null,null,null,0,'09-05-2011 13:25:33',null,null,'VAND',-259954.967,145092.123,-259802.657,145147.225,1,'10d6d8bc-b9b2-44bb-84bf-ceca42a0970a',425950,'09-05-2011 13:20:27','09-05-2011 13:20:58','Gravemaskine',null,null,'Ledningsoplysning','Kokbjerg',null,'Kolding',null,'59 23 44 55',null,null,'info#mail.com','FORSYNINGSLEDNINGER','vej 12','1700','Nyberg','NO','21491697',null,null,'mail#info.com','051055f4-ea2a-4cb3-a016-6f6477e6a342','MUNCK FORSYNINGSLEDNINGER A/S','Jon Andersen','vej 38 B','7100','Vejle','NO',null,'23681515','76409220','mail#info.com','09-05-2011 13:20:58','OK')")
mDatabase.ExecuteSql("delete from ler_order_coord where order_id = 101633")
mDatabase.ExecuteSql("insert into ler_order_coord (order_id,polygon_no,seq_no,east,north) values (101633,1,1,-259954.967,145120.599)")
mDatabase.ExecuteSql("insert into ler_order_coord (order_id,polygon_no,seq_no,east,north) values (101633,1,2,-259951.933,145092.123)")
mDatabase.ExecuteSql("insert into ler_order_coord (order_id,polygon_no,seq_no,east,north) values (101633,1,3,-259802.657,145111.956)")
mDatabase.Commit() 'This is where the error occurs
EDIT:
See my answer for how I solved this.
I have a follow-up question on this: Is it not allowed to run a select inside a transaction like this? Or can it be done by running the transaction in a specific isolation level (I see that the BeginTransaction method has an optional parameter for doing this) ? ..Or some other sollution..? In my case, it was not a problem to move the select to run before the transaction started, but what if you need to run selects that must run inside the transaction?
I found an answer to another question, which helped me along the way:
How to check if Dotnet transaction is rolled back?
I implemented the TransactionScope to have better control on my transaction, and I noticed a new error message in the log saying :
The Transaction Manager is not available. (Exception from HRESULT: 0x8004D01B)
This error was triggered on the select statement:
mOrderId = mDatabase.Value("select max(order_id) from ler_order")
I moved the select to before the transaction begins, and now it works!
EDIT:
I discovered that what triggered this error might not have been the use of TransactionScope, but that I tried to set lCommand.Transaction = mTransaction on the select command. This is apparently not allowed when the command is not an action command. This is however not the original problem, because the error on Commit was there before I tried to set the active transaction on the select command. This is just something I tried along the way trying to fix it.
I want to get back to get a list of users on a network domain using VB.Net.
I will have the domain name available to me for use.
Thanks in advance.
It might throw an error in the select query.
Please check this:
Did you add a reference to the System.Management assembly to your project? If you haven't, do this:
In VS, click on Project menu > add reference.
On the .Net tab, scroll down until you see System.Management. Click on it to select, then click OK.
Now back in your code, at the very top of your class, put in "Imports System.Management", and you should be all set.
Source:
http://www.vbforums.com/showthread.php?t=560422
It worked for me without any issues. I am able to get all user names for the domain.
Something like this might point you in the right direction, using System.DirectoryServices and System.DirectoryServices.ActiveDirectory:
Private Function GetDomainUsers(ByVal domainDirectoryEntry As DirectoryEntry, ByRef userList As IList) As Integer
Try
userList = New ArrayList()
Using domainDirectoryEntry
Dim ds As New DirectorySearcher(domainDirectoryEntry, "(&(objectCategory=person)(objectClass=user))", New String() {"distinguishedName"})
Using src As SearchResultCollection = ds.FindAll()
For Each sr As SearchResult In src
userList.Add(sr.Properties("distinguishedName")(0))
Next
End Using
End Using
Return userList.Count
Catch generatedExceptionName As Exception
userList = Nothing
Return -1
Finally
domainDirectoryEntry = Nothing
End Try
End Function
Imports System.Management
Imports System.Management.Instrumentation
Sub PrintDomainUsers()
Dim domainName As String = System.Environment.UserDomainName.ToString
Dim userQuery As SelectQuery = New SelectQuery("Win32_UserAccount", "Domain='" & domainName & "'")
Try
Dim userSearch As ManagementObjectSearcher = New ManagementObjectSearcher(userQuery)
For Each domainUser In userSearch.Get
Console.WriteLine(domainUser("Name"))
Next
Catch ex As Exception
Throw ex
End Try
End Sub
This works but how do i filter by a certain group. Im getting THOUSANDS of resutls
Another option would be exploring System.Management and System.Management.Instrumentation.Here is a short snippet of how you pull the users of a particular domain using these namespaces.
Imports System.Management
Imports System.Management.Instrumentation
Sub PrintDomainUsers()
Dim domainName As String = System.Environment.UserDomainName.ToString
Dim userQuery As SelectQuery = New SelectQuery("Win32_UserAccount", "Domain='" & domainName & "'")
Try
Dim userSearch As ManagementObjectSearcher = New ManagementObjectSearcher(userQuery)
For Each domainUser In userSearch.Get
Console.WriteLine(domainUser("Name"))
Next
Catch ex As Exception
Throw ex
End Try
End Sub