This message is displayed when running my windows service.
The [service name] service on local computer started and then stopped.
Some Services stop automatically if they are not in use by another services or programs.
I am not sure what is causing this error. Below is the code for my service. My code uses another class called MagentoSalesOrder. I ran this code as a console application first and it worked just fine. I believe this what is causing the error. When I comment out the lines that use that class my service runs fine for printing test to a file.
Imports MyFirstService.MagentoSalesOrder
Public Class MyFirstService
Dim WithEvents timer1 As New System.Timers.Timer
Protected Overrides Sub OnStart(ByVal args() As String)
timer1.Interval = 10000
timer1.Start()
WriteLog(Me.ServiceName & " has started ...")
End Sub
Protected Overrides Sub OnStop()
WriteLog(Me.ServiceName & " has stopped ...")
End Sub
Private Sub timer1_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs) Handles timer1.Elapsed
WriteLog(Me.ServiceName & " is running ...")
End Sub
Private Sub WriteLog(ByVal strMessage As String)
Dim strPath As String, file As System.IO.StreamWriter
Dim test As New MagentoSalesOrder()
strPath = AppDomain.CurrentDomain.BaseDirectory & "\MyService.log"
file = New System.IO.StreamWriter(strPath, True)
Dim arr = test.BuildPreOrder()
If (arr.Length > 0) Then
For Each element As Long In arr
file.WriteLine("PreOrder created: " + element)
Next
Else
file.WriteLine("No orders to process")
End If
'file.WriteLine("Test")
file.Close()
End Sub
End Class
So I found out my error was coming from the file.writeline in my foreach loop.
Changing element to element.toString in my writefile fixed my service.
The problem came from trying to concatenate a Long to a String.
Changing element to element.toString in my writefile fixed my service.
Related
First a little background information: The purpose of this application is to capture images and save them automatically to a network directory that will be either created or appended using the input of the text box. This code DOES work on my computer (windows 7 home 64 bit). I've created it using microsoft visual basic express 2010.
However..... when attempting to run the application on a windows 10 tablet, I get the follow errors:
On form load:
An error occurred while capturing the image. The video capture will now be terminated.
Object reference not set to an instance of an object.
On button2_Click Event:
Object reference not set to an instance of an object.
Below is the entirety of the code.
Form2.vb
Public Class Form2
Public scanIsSet As Boolean
Private webcam As WebCam
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
webcam = New WebCam()
webcam.InitializeWebCam(imgVideo)
webcam.Start()
scanIsSet = False
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim CFGfile As String
Dim SaveDir As String
Dim imgIndex As Integer
Dim existingImages() As String
SaveDir = "C:\somepath\"
'save image to directory with index number
Try
imgCapture.Image.Save(SaveDir & OrderNumber.Text & "\" & CStr(imgIndex) & ".jpg")
Catch ex As Exception
MsgBox("error while accessing object imgCapture" & ex.Message)
End Try
imgIndex = imgIndex + 1
Else
Beep()
MsgBox("Please scan or type in order number first")
End If
End Sub
End Class
WebCam.vb
Imports System
Imports System.IO
Imports System.Linq
Imports System.Text
Imports WebCam_Capture
Imports System.Collections.Generic
Imports ZXing
Imports ZXing.OneD
'Design by Pongsakorn Poosankam
Class WebCam
Public scanz As Boolean
Public Sub setScan(ByVal x As Boolean)
scanz = x
End Sub
Private webcam As WebCamCapture
Private _FrameImage As System.Windows.Forms.PictureBox
Private FrameNumber As Integer = 30
Public Sub InitializeWebCam(ByRef ImageControl As System.Windows.Forms.PictureBox)
webcam = New WebCamCapture()
webcam.FrameNumber = CULng((0))
webcam.TimeToCapture_milliseconds = FrameNumber
AddHandler webcam.ImageCaptured, AddressOf webcam_ImageCaptured
_FrameImage = ImageControl
End Sub
Private Sub webcam_ImageCaptured(ByVal source As Object, ByVal e As WebcamEventArgs)
_FrameImage.Image = e.WebCamImage
If scanz = True Then
Dim BCreader As New ZXing.BarcodeReader
'BCreader.Options.TryHarder = True
Try
Dim resu As Result = BCreader.Decode(e.WebCamImage)
Form2.OrderNumber.Text = resu.Text
setScan(False)
Form2.Label2.Text = ""
Beep()
Catch ex As Exception
'do nothing
End Try
End If
End Sub
Public Sub Start()
webcam.TimeToCapture_milliseconds = FrameNumber
webcam.Start(0)
End Sub
Public Sub [Stop]()
webcam.[Stop]()
End Sub
Public Sub [Continue]()
' change the capture time frame
webcam.TimeToCapture_milliseconds = FrameNumber
' resume the video capture from the stop
webcam.Start(Me.webcam.FrameNumber)
End Sub
Public Sub ResolutionSetting()
webcam.Config()
End Sub
Public Sub AdvanceSetting()
webcam.Config2()
End Sub
End Class
As you can see toward the end of Form2.vb, I've wrapped imgCapture.Image.Save(SaveDir & OrderNumber.Text & "\" & CStr(imgIndex) & ".jpg") in a Try-Catch block because I suspect it's some sort of problems with the pictureBox objects. The try catch block does indeed catch the exception, but I still have no idea what the problem is, why it happens on the tablet and not the PC, or how to fix it.
I've found similar questions, but none with a solution I can make use of.
Since you are using a library, EasyWebCam, that is outdated and not compatible with Win10, I would suggest switching libraries. Other options out there:
DirectX.Capture
Windows.Media.Capture
I FOUND THE SOLUTION BUT I DON'T KNOW IF YOU NEED IT NOW ANYWAY THE PROBLEM IS IF YOU HAVE CHANGED THE PICTUREBOX NAME THEN IN REFENCES USE THE EXACT NAME YOU HAVE CHANGED TO. EXAMPLE IF I CHANGE ALL MY PICTUREBOX NAMES AS -
PictureBox_A1 , PictureBox_A2 ,... and so on then my refence should be as -
Dim r As DataRow
For Each r In t1.Rows
CType(Controls("PictureBox_" & r(2)), PictureBox).Image = bookedicon
Next
MY REFERENCE IS - "PictureBox_"
i am writing a simple program to get the all the properties of a process like ffmpeg . i got most properties of predefined functions but i want to know the argument which i gave to the ffmpeg in vb.net?
For Each prog As Process In Process.GetProcesses
If prog.ProcessName = "ffmpeg" Then
al.Add(prog.Id)
End If
Next
For Each id In al
Dim p As Process = Process.GetProcessById(id)
listBox3.Items.Add(Process.GetProcessById(id).ProcessName)
ListBox3.Items.Add(p.BasePriority)
ListBox3.Items.Add(p.HandleCount)
ListBox3.Items.Add(p.Id)
ListBox3.Items.Add(p.MainWindowTitle)
ListBox3.Items.Add(p.MaxWorkingSet)
ListBox3.Items.Add(p.MinWorkingSet)
ListBox3.Items.Add(p.PriorityBoostEnabled)
ListBox3.Items.Add(p.PriorityClass)
ListBox3.Items.Add(p.PrivilegedProcessorTime)
ListBox3.Items.Add(p.ProcessName)
ListBox3.Items.Add(p.ProcessorAffinity)
ListBox3.Items.Add(p.StartTime)
ListBox3.Items.Add(p.TotalProcessorTime)
ListBox3.Items.Add(p.UserProcessorTime)
lastBox3.Items.Add(p.WaitForInputIdle)
ListBox3.Items.Add("========================")
Next id
Using Jesse Slicer's code as a base from here:
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
For Each proc As Process In Process.GetProcessesByName("ffmpeg")
Debug.Print("ID: " & proc.Id)
Debug.Print("Arguments: " & proc.GetCommandLine)
Debug.Print("------------------------------")
Next
End Sub
End Class
Public Module Extensions
<Runtime.CompilerServices.Extension()>
Public Function GetCommandLine(ByVal proc As Process) As String
' Project --> Add Reference --> System.Management
Dim arguments As New System.Text.StringBuilder
Using searcher As New Management.ManagementObjectSearcher("SELECT CommandLine FROM Win32_Process WHERE ProcessId = " & proc.Id)
For Each arg In searcher.Get
arguments.Append(arg("CommandLine") & " ")
Next
End Using
Return arguments.ToString.Trim
End Function
End Module
Note that you need to add the System.Management reference, and I made the function an extension method of the Process class.
ffmpeg is open source, so Might it will be useful:
https://ffmpeg.org/documentation.html
I apologize in advance if my question is too long-winded. I looked at the question “How to update data in GUI with messages that are being received by a thread of another class?” and it is very close to what I am trying to do but the answer was not detailed enough to be helpful.
I have converted a VB6 app to VB.NET (VS2013). The main function of the app is to send queries to a Linux server and display the results on the calling form. Since the WinSock control no longer exists, I’ve created a class to handle the functions associated with the TcpClient class. I can successfully connect to the server and send and receive data.
The problem is that I have multiple forms that use this class to send query messages to the server. The server responds with data to be displayed on the calling form. When I try to update a control on a form, I get the error "Cross-thread operation not valid: Control x accessed from a thread other than the thread it was created on." I know I’m supposed to use Control.InvokeRequired along with Control.Invoke in order to update controls on the Main/UI thread, but I can’t find a good, complete example in VB. Also, I have over 50 forms with a variety of controls on each form, I really don’t want to write a delegate handler for each control. I should also mention that the concept of threads and delegates is very new to me. I have been reading everything I can find on this subject for the past week or two, but I’m still stuck!
Is there some way to just switch back to the Main Thread? If not, is there a way I can use Control.Invoke just once to cover a multitude of controls?
I tried starting a thread just after connecting before I start sending and receiving data, but netStream.BeginRead starts its own thread once the callback function fires. I also tried using Read instead of BeginRead. It did not work well if there was a large amount of data in the response, BeginRead handled things better. I feel like Dorothy stuck in Oz, I just want to get home to the main thread!
Thanks in advance for any help you can provide.
Option Explicit On
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.Threading
Friend Class ATISTcpClient
Public Event Receive(ByVal data As String)
Private Shared WithEvents oRlogin As TcpClient
Private netStream As NetworkStream
Private BUFFER_SIZE As Integer = 8192
Private DataBuffer(BUFFER_SIZE) As Byte
Public Sub Connect()
Try
oRlogin = New Net.Sockets.TcpClient
Dim localIP As IPAddress = IPAddress.Parse(myIPAddress)
Dim localPrt As Int16 = myLocalPort
Dim ipLocalEndPoint As New IPEndPoint(localIP, localPrt)
oRlogin = New TcpClient(ipLocalEndPoint)
oRlogin.NoDelay = True
oRlogin.Connect(RemoteHost, RemotePort)
Catch e As ArgumentNullException
Debug.Print("ArgumentNullException: {0}", e)
Catch e As Net.Sockets.SocketException
Debug.Print("SocketException: {0}", e)
End Try
If oRlogin.Connected() Then
netStream = oRlogin.GetStream
If netStream.CanRead Then
netStream.BeginRead(DataBuffer, 0, BUFFER_SIZE, _
AddressOf DataArrival, DataBuffer)
End If
Send(vbNullChar)
Send(User & vbNullChar)
Send(User & vbNullChar)
Send(Term & vbNullChar)
End If
End Sub
Public Sub Send(newData As String)
On Error GoTo send_err
If netStream.CanWrite Then
Dim sendBytes As [Byte]() = Encoding.UTF8.GetBytes(newData)
netStream.Write(sendBytes, 0, sendBytes.Length)
End If
Exit Sub
send_err:
Debug.Print("Error in Send: " & Err.Number & " " & Err.Description)
End Sub
Private Sub DataArrival(ByVal dr As IAsyncResult)
'This is where it switches to a WorkerThread. It never switches back!
On Error GoTo dataArrival_err
Dim myReadBuffer(BUFFER_SIZE) As Byte
Dim myData As String = ""
Dim numberOfBytesRead As Integer = 0
numberOfBytesRead = netStream.EndRead(dr)
myReadBuffer = DataBuffer
myData = myData & Encoding.ASCII.GetString(myReadBuffer, 0, numberOfBytesRead)
Do While netStream.DataAvailable
numberOfBytesRead = netStream.Read(myReadBuffer, 0, myReadBuffer.Length)
myData = myData & Encoding.ASCII.GetString(myReadBuffer, 0, numberOfBytesRead)
Loop
'Send data back to calling form
RaiseEvent Receive(myData)
'Start reading again in case we don‘t have the entire response yet
If netStream.CanRead Then
netStream.BeginRead(DataBuffer, 0,BUFFER_SIZE,AddressOf DataArrival,DataBuffer)
End If
Exit Sub
dataArrival_err:
Debug.Print("Error in DataArrival: " & err.Number & err.Description)
End Sub
Instead of using delegates one could use anonymous methods.
Singleline:
uicontrol.Window.Invoke(Sub() ...)
Multiline:
uicontrol.Window.Invoke(
Sub()
...
End Sub
)
If you don't want to pass an UI control every time you need to invoke, create a custom application startup object.
Friend NotInheritable Class Program
Private Sub New()
End Sub
Public Shared ReadOnly Property Window() As Form
Get
Return Program.m_window
End Get
End Property
<STAThread()> _
Friend Shared Sub Main()
Application.EnableVisualStyles()
Application.SetCompatibleTextRenderingDefault(False)
Dim window As New Form1()
Program.m_window = window
Application.Run(window)
End Sub
Private Shared m_window As Form
End Class
Now, you'll always have access to the main form of the UI thread.
Friend Class Test
Public Event Message(text As String)
Public Sub Run()
Program.Window.Invoke(Sub() RaiseEvent Message("Hello!"))
End Sub
End Class
In the following sample code, notice that the Asynchronous - Unsafe run will throw a Cross-thread exception.
Imports System.Threading
Imports System.Threading.Tasks
Public Class Form1
Public Sub New()
Me.InitializeComponent()
Me.cbOptions = New ComboBox() With {.TabIndex = 0, .Dock = DockStyle.Top, .DropDownStyle = ComboBoxStyle.DropDownList} : Me.cbOptions.Items.AddRange({"Asynchronous", "Synchronous"}) : Me.cbOptions.SelectedItem = "Asynchronous"
Me.btnRunSafe = New Button() With {.TabIndex = 1, .Dock = DockStyle.Top, .Text = "Run safe!", .Height = 30}
Me.btnRunUnsafe = New Button() With {.TabIndex = 2, .Dock = DockStyle.Top, .Text = "Run unsafe!", .Height = 30}
Me.tbOutput = New RichTextBox() With {.TabIndex = 3, .Dock = DockStyle.Fill}
Me.Controls.AddRange({Me.tbOutput, Me.btnRunUnsafe, Me.btnRunSafe, Me.cbOptions})
Me.testInstance = New Test()
End Sub
Private Sub _ButtonRunSafeClicked(s As Object, e As EventArgs) Handles btnRunSafe.Click
Dim mode As String = CStr(Me.cbOptions.SelectedItem)
If (mode = "Synchronous") Then
Me.testInstance.RunSafe(mode)
Else 'If (mode = "Asynchronous") Then
Task.Factory.StartNew(Sub() Me.testInstance.RunSafe(mode))
End If
End Sub
Private Sub _ButtonRunUnsafeClicked(s As Object, e As EventArgs) Handles btnRunUnsafe.Click
Dim mode As String = CStr(Me.cbOptions.SelectedItem)
If (mode = "Synchronous") Then
Me.testInstance.RunUnsafe(mode)
Else 'If (mode = "Asynchronous") Then
Task.Factory.StartNew(Sub() Me.testInstance.RunUnsafe(mode))
End If
End Sub
Private Sub TestMessageReceived(text As String) Handles testInstance.Message
Me.tbOutput.Text = (text & Environment.NewLine & Me.tbOutput.Text)
End Sub
Private WithEvents btnRunSafe As Button
Private WithEvents btnRunUnsafe As Button
Private WithEvents tbOutput As RichTextBox
Private WithEvents cbOptions As ComboBox
Private WithEvents testInstance As Test
Friend Class Test
Public Event Message(text As String)
Public Sub RunSafe(mode As String)
'Do some work:
Thread.Sleep(2000)
'Notify any listeners:
Program.Window.Invoke(Sub() RaiseEvent Message(String.Format("Safe ({0}) # {1}", mode, Date.Now)))
End Sub
Public Sub RunUnsafe(mode As String)
'Do some work:
Thread.Sleep(2000)
'Notify any listeners:
RaiseEvent Message(String.Format("Unsafe ({0}) # {1}", mode, Date.Now))
End Sub
End Class
End Class
Thank you to those who took the time to make suggestions. I found a solution. Though it may not be the preferred solution, it works beautifully. I simply added MSWINSCK.OCX to my toolbar, and use it as a COM/ActiveX component. The AxMSWinsockLib.AxWinsock control includes a DataArrival event, and it stays in the Main thread when the data arrives.
The most interesting thing is, if you right click on AxMSWinsockLib.DMSWinsockControlEvents_DataArrivalEvent and choose Go To Definition, the object browser shows the functions and delegate subs to handle the asynchronous read and the necessary delegates to handle BeginInvoke, EndInvoke, etc. It appears MicroSoft has already done the hard stuff that I did not have the time or experience to figure out on my own!
I'm attempting to make a multi-threaded download manager that has a limit of 4 concurrent downloads. In my research, I came across the following: C# Downloader: should I use Threads, BackgroundWorker or ThreadPool?
[edit] updated code:
Imports System.Net
Imports System.Collections.Concurrent
Imports System.ComponentModel
Imports System.Threading
Public Class Form1
Const MaxClients As Integer = 4
' create a queue that allows the max items
Dim ClientQueue As New BlockingCollection(Of WebClient)(MaxClients)
' queue of urls to be downloaded (unbounded)
Dim UrlQueue As New Queue(Of String)()
Dim downloadThread As Thread
'Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
' create four WebClient instances and put them into the queue
For i As Integer = 0 To MaxClients - 1
Dim cli = New WebClient()
AddHandler cli.DownloadFileCompleted, AddressOf DownloadFileCompleted
AddHandler cli.DownloadProgressChanged, AddressOf DownloadProgressChanged
ClientQueue.Add(cli)
Next
' Fill the UrlQueue here
UrlQueue.Enqueue("http://www.gnu.org/licenses/gpl-1.0.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/gpl-2.0.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/gpl-3.0.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/lgpl-2.1.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/lgpl-3.0.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/fdl-1.1.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/fdl-1.2.txt")
UrlQueue.Enqueue("http://www.gnu.org/licenses/fdl-1.3.txt")
downloadThread = New Thread(AddressOf downloadQueue)
downloadThread.IsBackground = True
downloadThread.Start()
End Sub
Private Sub downloadQueue()
' Now go until the UrlQueue is empty
While UrlQueue.Count > 0
Dim cli As WebClient = ClientQueue.Take() ' blocks if there is no client available
Dim url As String = UrlQueue.Dequeue()
Dim fname As String = CreateOutputFilename(url)
cli.DownloadFileAsync(New Uri(url), fname, New DownloadArgs(url, fname, cli))
AppendText(url & " started" & vbCrLf)
End While
End Sub
Private Sub DownloadProgressChanged(sender As Object, e As DownloadProgressChangedEventArgs)
Dim args As DownloadArgs = DirectCast(e.UserState, DownloadArgs)
' Do status updates for this download
End Sub
Private Sub DownloadFileCompleted(sender As Object, e As AsyncCompletedEventArgs)
Dim args As DownloadArgs = DirectCast(e.UserState, DownloadArgs)
' do whatever UI updates
Dim url As String = "Filename" '<============I'd like to be able to pass the filename or URL but can't figure this out
AppendText(url & " completed" & vbCrLf)
' now put this client back into the queue
ClientQueue.Add(args.Client)
End Sub
Public Function CreateOutputFilename(ByVal url As String) As String
Try
Return url.Substring(url.LastIndexOf("/") + 1)
Catch ex As Exception
Return url
End Try
End Function
Private Delegate Sub SetTextCallback(text As String)
Private Sub AppendText(text As String)
If Me.TextBox1.InvokeRequired Then
TextBox1.Invoke(New Action(Of String)(AddressOf AppendText), text)
Return
End If
Me.TextBox1.AppendText(text)
Me.TextBox1.SelectionStart = TextBox1.TextLength
Me.TextBox1.ScrollToCaret()
End Sub
End Class
Class DownloadArgs
Public ReadOnly Url As String
Public ReadOnly Filename As String
Public ReadOnly Client As WebClient
Public Sub New(u As String, f As String, c As WebClient)
Url = u
Filename = f
Client = c
End Sub
End Class
This will successfully download the first 4 files in the UrlQueue, but it then seems to freeze and no further files download. I'd imagine the problem lies in something minor I missed in the process of converting from C# to vb.net, but I can't seem to figure this out.
ClientQueue.Take() blocks the UI thread. Also, WebClient will want to raise the DownloadFileCompleted event on the UI thread - but it is already blocked by ClientQueue.Take(). You have a deadlock.
To resolve this, you got to move your blocking loop to another background thread.
You are blocking the ability for your async queue to process. Not sure this is the "Correct" way to do this but the changes here make it work:
While UrlQueue.Count > 0
Do While ClientQueue.Count = 0
Application.DoEvents()
Loop
Dim cli As WebClient = ClientQueue.Take() ' blocks if there is no client available
Dim url As String = UrlQueue.Dequeue()
Dim fname As String = CreateOutputFilename(url) ' or however you get the output file name
cli.DownloadFileAsync(New Uri(url), fname, New DownloadArgs(url, fname, cli))
End While
I'm having an issue where my main form isn't updating even though I see the event fire off. Let me explain the situation and share some of my code which I'm sure will be horrible since I'm an amateur.
I created a class to take in the settings for running a process in the background. I add some custom events in that class so I could use that in my form instead of a timer.
I put a break on the two subs for that handle those events and I see them get kicked off as soon as an install starts.
I look at the data and it's coming across and no exceptions are thrown.
At first I thought it was because the datagridview had some latency issues. I set that to be double buffered through some tricks I found but it didn't matter. There was still a roughly 10 second delay before the data showed up in the datagrid.
I thought about it and decided I really didn't need a datagridview and replaced the control with a multiline textbox, but it didn't make a difference. It's still taking 10 seconds or longer to show updates to the form/textbox.
I've included some of my code below.
Public Shared WithEvents np As NewProcess
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Try
np = New NewProcess
AddHandler np.InstallFinished, AddressOf np_InstallFinished
AddHandler np.InstallStarted, AddressOf np_InstallStarted
Catch ex As Exception
End Try
End Sub
Protected Sub np_InstallFinished(ByVal Description As String, ByVal ExitCode As Integer)
InstallInProcess = False
If Not Description = Nothing Then
If Not ExitCode = Nothing Then
AddLog(String.Format("Completed install of {0} ({1}).", Description, ExitCode))
Else
AddLog(String.Format("Completed install of {0}.", Description))
End If
End If
RefreshButtons()
UpdateListofApps()
np.Dispose()
End Sub
Protected Sub np_InstallStarted(ByVal Description As String)
InstallInProcess = True
If Not Description = Nothing Then AddLog(String.Format("Started the install of {0}.", Description))
End Sub
Public Class NewProcess
Dim ProcessName As String
Dim ProcessVisibile As Boolean
Dim Arguments As String
Dim WaitforExit As Boolean
Dim Description As String
Dim ShellExecute As Boolean
Dim EC As Integer = Nothing 'Exit Code
Private IsBusy As Boolean = Nothing
Dim th As Threading.Thread
Public Event InstallFinished(ByVal Description As String, ByVal ExitCode As Integer)
Public Event InstallStarted(ByVal Description As String)
Public Function Busy() As Boolean
If IsBusy = Nothing Then Return False
Return IsBusy
End Function
Public Function ExitCode() As Integer
Return EC
End Function
Public Function ProcessDescription() As String
Return Description
End Function
''' <summary>
''' Starts a new multithreaded process.
''' </summary>
''' <param name="path">Path of the File to run</param>
''' <param name="Visible">Should application be visible?</param>
''' <param name="Arg">Arguments</param>
''' <param name="WaitforExit">Wait for application to exit?</param>
''' <param name="Description">Description that will show up in logs</param>
''' <remarks>Starts a new multithreaded process.</remarks>
Public Sub StartProcess(ByVal path As String, ByVal Visible As Boolean, Optional ByVal Arg As String = Nothing, Optional ByVal WaitforExit As Boolean = False, Optional ByVal Description As String = Nothing)
Try
Me.ProcessName = path
Me.ProcessVisibile = Visible
If Arguments = Nothing Then Me.Arguments = Arg
Me.Description = Description
Me.WaitforExit = WaitforExit
If IsBusy And WaitforExit Then
MessageBox.Show("Another install is already in process, please wait for previous install to finish.", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning)
Exit Sub
End If
If Not fn_FileExists(ProcessName) Then
MessageBox.Show("Could not find file " & ProcessName & ".", "Could not start process because file is missing.", MessageBoxButtons.OK, MessageBoxIcon.Error)
Exit Sub
End If
th = New Threading.Thread(AddressOf NewThread)
With th
.IsBackground = True
If Not Description Is Nothing Then .Name = Description
.Start()
End With
Catch ex As Exception
End Try
End Sub
Private Sub NewThread()
Dim p As Process
Try
p = New Process
With p
.EnableRaisingEvents = True
.StartInfo.Arguments = Arguments
.StartInfo.FileName = ProcessName
.StartInfo.CreateNoWindow = ProcessVisibile
End With
If ProcessVisibile Then
p.StartInfo.WindowStyle = ProcessWindowStyle.Normal
Else
p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden
End If
p.Start()
IsBusy = True
RaiseEvent InstallStarted(Description)
If WaitforExit Then
Do While p.HasExited = False
Threading.Thread.Sleep(500)
Loop
IsBusy = False
RaiseEvent InstallFinished(Description, p.ExitCode)
End If
EC = p.ExitCode
Catch ex As Exception
End Try
End Sub
Public Sub Dispose()
ProcessName = Nothing
ProcessVisibile = Nothing
Arguments = Nothing
WaitforExit = Nothing
Description = Nothing
EC = Nothing
InstallInProcess = Nothing
th.Join()
MemoryManagement.FlushMemory()
End Sub
End Class
Sub AddLog(ByVal s As String)
Try
s = String.Format("[{0}] {1}", TimeOfDay.ToShortTimeString, s)
Form1.tbLogs.AppendText(s & vbCrLf)
Using st As New StreamWriter(LogFilePath, True)
st.WriteLine(s)
st.Flush()
End Using
Catch ex As Exception
End Try
End Sub
Any idea's? I'm at a complete loss.
I've tried adding application.doevents, me.refresh and quite a few other things :(
Form1.tbLogs.AppendText(s & vbCrLf)
Standard VB.NET trap. Form1 is a class name, not a reference to the form. Unfortunately, VB.NET implemented an anachronism from VB6 where that was legal. It however falls apart when you use threads. You'll get another form object automatically created, one that isn't visible because its Show() method was never called. Otherwise dead as a doornail since the thread is not pumping a message loop.
You'll need to pass a reference to the actual form object that the user is looking at to the worker class. The value of Me in the Form1 code. You will also have to use Control.Invoke since it isn't legal to update controls from another thread. I recommend you fire an event instead, one that Form1 can subscribe to, so that your worker class isn't infected with implementation details of the UI.
Some suggestions:
First make it work without threads. (Ironical you call yourself an amateur, It so happened I only learned to do that after I was past the 'amateur' stage)
Don't try to update the GUI Controls from a background thread. That's forbidden in windows. I'm not sure that's what you do (no VB guru), but it sure looks like it.
Use the .net BackgroundWorker class. It has builtin functionality to talk back to the main thread from a background thread. It's not perfect but a good start.
You got me pointed in the right direction. Thanks Hans. This was my solution:
Private Sub SetText(ByVal [text] As String)
If Me.tbLogs.InvokeRequired Then
Dim d As New SetTextCallback(AddressOf SetText)
Me.Invoke(d, New Object() {[text]})
Else
Me.tbLogs.Text = [text]
End If
End Sub
Private Sub np_InstallStarted(ByVal Description As String)
InstallInProcess = True
If Me.tbLogs.Text = "" Then
SetText(String.Format("[{0}] Started the install of {1}.{2}", TimeOfDay.ToShortTimeString, Description, vbCrLf))
Else
SetText(tbLogs.Text & vbCrLf & String.Format("[{0}] Started the install of {1}.{2}", TimeOfDay.ToShortTimeString, Description, vbCrLf))
End If
End Sub
Private Sub np_InstallFinished(ByVal [Description] As String, ByVal [ExitCode] As Integer)
InstallInProcess = False
If Not Description = Nothing Then
If Not ExitCode = Nothing Then
SetText(tbLogs.Text & vbCrLf & String.Format("[{0}] Completed install of {1} ({2}).{3}", TimeOfDay.ToShortTimeString, Description, ExitCode, vbCrLf))
Else
SetText(tbLogs.Text & vbCrLf & String.Format("[{0}] Completed install of {1}.{3}", TimeOfDay.ToShortTimeString, Description, vbCrLf))
End If
End If
RefreshButtons()
UpdateListofApps()
np.Dispose()
End Sub
So when the event kicks off that the install has started or finished, I use the SetText to update the log on the original form.
Problem is I posted that original post as an "unregistered user" so now I'm trying to figure out a way to say the question was answered. Thanks again for your help!