i have a serializable class
<Serializable()> Public Class SACCVar
Private _ConsigneCompression As Integer
Public Event VariableChanged(ByVal Val As Object, ByVal Old_Val As Object, desc As String)
Public Property ConsigneCompression As Integer
Get
Return _ConsigneCompression
End Get
Set(value As Integer)
Tmp_Val = _ConsigneCompression
_ConsigneCompression = value
RaiseEvent VariableChanged(_ConsigneCompression, Tmp_Val, "ConsigneCompression")
End Set
End Property End Class
In a module i declare my variable as class and implement my raise function
Public WithEvents MesuresVal As New MesuresVar
Public Sub SaccVarChanged(ByVal Val, ByVal Old_Value, DictKeyDesc) Handles SaccData.VariableChanged
For Each item As CtrlItem In SaccData.DicOfControl(DictKeyDesc)
Dim pinstance As PropertyInfo = item.Ctrl.GetType.GetProperty(item.prop)
pinstance.SetValue(item.Ctrl, Val)
Next End Sub
In the code when i do
SaccData.ConsigneCompression = 1234
it call SaccVarChanged
but when i call my subroutines that Deserialize my class it pass on the RaiseEvent VariableChanged part of the code in my "public property". But it didn't raise the SaccVarChanged sub.
Is there anything i can do for that?
Thank you
EDIT :
here is my serialize /deserialize code :
Dim fichier As String
fichier = Fichier_SACC
' Déclaration
Dim XSSACC As New XmlSerializer(SaccData.GetType)
Dim streamSACC As FileStream
If Not File.Exists(fichier) Then
'Exit Sub
'TODO gestion erreur
Else
streamSACC = New FileStream(fichier, FileMode.Open)
Try
SaccData = CType(XSSACC.Deserialize(streamSACC), SACCVar)
Catch ex As Exception
' Propagrer l'exception
Throw ex
Finally
' En cas d'erreur, n'oublier pas de fermer le flux en lecture si ce dernier est toujours ouvert
streamSACC.Close()
End Try
End If
Dim StreamSACC As New StreamWriter(Fichier_SACC)
Dim serialiseSACC As New XmlSerializer(SaccData.GetType)
Try
serialiseSACC.Serialize(StreamSACC, SaccData)
Catch ex As Exception
Throw ex
Finally
StreamSACC.Close()
End Try
Ok i finally get it working...
thanks to here : Events not working with after Deserialization
i found that Deserialization remove the handler of the event. It seems that deserialization create a new instance of my object.
The solution give in the link is something like :
<OnDeserialized()>
Private Sub OnDeserializedMethod(ByVal Context As StreamingContext)
AddHandler Child.Changed AddressOf Me.Child_Changed
End Sub
But that didn't work for me as i am using xmlserialiser wich seems not implement with call back (a question of compatibility with framework 1.1 i read...)
Instead i am using a flag that i test in my "new" method.
everything is working as i expect.
Thanks once again #plutonix..
Related
I have an application whose main window upon click of a button gives users an option to load a list of files in the cloud.
Private Sub ImportCloudContent()
Dim cloudForm As Form_CloudImport
cloudForm = New Form_CloudImport()
cloudForm.Show()
cloudForm.populateDataGrid()
AddHandler cloudForm._DownloadComplete, New EventHandler(AddressOf OpenProject)
cloudForm.DownloadNotifier(FullPathOfContent)
End Sub
Ideally I should be able to get the value of the FullPathOfContent variable and pass it onto Open Project, but I am not sure how to go about it.
In the new Window users can click and download the file they want. Below is the section of code that handles the download in the Form_CloudImport class :
Private Async Sub Btn_download_Click(sender As Object, e As EventArgs) Handles Btn_download.Click
Dim fileNameRows As DataGridViewSelectedRowCollection = datagridview_cloudContent.SelectedRows
Dim fileName As String
Dim fileType As String = Cloud.CONTENT
Dim FullPathOfContent As String
For Each fileNameRow As DataGridViewRow In fileNameRows
fileName = fileNameRow.Cells(0).Value.ToString() & ".zip"
Try
FullPathOfContent = CloudToCCT(fileName, fileType)
Catch ex As Exception
CSMessageBox.ShowError("Content Import failed : ", ex)
End Try
Next
Me.Close()
DownloadNotifier(FullPathOfContent)
End Sub
Once the download is complete, the main window needs to call some of its methods. I am new to VB and have created a custom event to facilitate this(again in the Form_CloudImport class)
Public Event _DownloadComplete(e As String)
Public Sub DownloadNotifier(FullPathOfContent As String)
RaiseEvent _DownloadComplete(FullPathOfContent)
End Sub
According to what have read, once the download method is complete, it will fire the DownloadNotifier method, which will raise the _DownloadComplete event and the MainWindow should trigger the following events.
However, I receive the below errors in the MainWindow part of the code :
Value of type 'MainWindow.EventHandler' cannot be converted to 'Form_CloudImport._DownloadCompleteEventHandler'
and
'FullPathOfContent' is not declared. It may be inaccessible due to its protection level.
This question seems to be very long but any help would be appreciated. Thank you in advance!
First things first, you should create a type and event with proper names and signature and raise it properly.
Public Class CloudImportForm
Public Event DownloadComplete As EventHandler(Of DownloadCompleteEventArgs)
Protected Overridable Sub OnDownloadComplete(e As DownloadCompleteEventArgs)
RaiseEvent DownloadComplete(Me, e)
End Sub
'...
End Class
Public Class DownloadCompleteEventArgs
Inherits EventArgs
Public Sub New(contentPath As String)
Me.ContentPath = contentPath
End Sub
Public ReadOnly Property ContentPath As String
End Class
In that form, you would have code that performed a download and then raised that event.
'...
Dim contentPath = GetContentPath()
'Perform download here.
'Raise event.
OnDownloadComplete(New DownloadCompleteEventArgs(contentPath))
In your main form you would create and configure the download form, which includes handling the event, and then display it.
Dim cloudForm As New CloudImportForm
AddHandler cloudForm.DownloadComplete, AddressOf CloudImportForm_DownloadComplete
cloudForm.PopulateDataGrid()
cloudForm.Show()
The method you specify as the event handler should have the appropriate signature and it should retrieve the content path from the e parameter.
Private Sub CloudImportForm_DownloadComplete(sender As Object, e As DownloadCompleteEventArgs)
Dim contentPath = e.ContentPath
'Use contentPath here.
End Sub
I was beginning to think that I was getting good at VB.net, but not this one has me stumped.
Code looks something like this
Public Class MyServer
.....
Public myMQTTclient = New MqttClient("www.myserv.com")
.....
Private Sub Ruptela_Server(sender As Object, e As EventArgs) Handles
MyBase.Load
<some code>
StartMQTT()
<some more code>
MQTT_Publish(.....)
End Sub
Public Function StartMQTT()
' Establish a connection
Dim code As Byte
Try
code = myMQTTclient.Connect(MQTT_ClientID)
Catch ex As Exception
<error handling code>
End Try
Return code
End Function
Public Sub MQTT_Publish(ByVal DeviceID As String, ByVal Channel As String, ByVal ChannelType As String, ByVal Value As String, ByVal Unit As String)
Dim myTopic As String = "MyTopic"
Dim myPayload As String = "My Payload"
Dim msgId As UShort = myMQTTclient.Publish(myTopic, Encoding.UTF8.GetBytes(myPayload), MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE, False)
End Sub
As this stands it works 100% OK. The coding may seem a bit odd, but the intent is as follows :
a) create an object 'myMQTTclient' at module level so it has scope throughout the module
b) run StartMQTT() - It can still see the object.
c) within main program call MQTT_Publish many times - I can still see the object
Now the issue is this... it all goes well until "www.myserv.com" fails DNS, then the underlying winsock code throws an exception.
So ... I'm thinking - no problem - just wrap the declaration in a try block or check that www.myserv.com exists before launching the declaration.
Ah, but you can't put code at module level, it has to be in a sub or function.
Hmmm... now I'm stumped. There has to be a 'proper' way to do this, but I'll be darned if I can figure it out.
Anyone able to help ?
I'd follow the advice from #djv about declaring it just as you need it. To wrap that in a Try... Catch block you can do that in an Init method.
Public Class MyServer
Implements IDisposable ' As per djv recommendation which I second...
Private myMQQTclient As MqttClient
Public Sub Init()
Try
myMQQTClient = New MqttClient("<your url>")
Catch ex As Exception
' Do whatever
End Try
End Sub
' more code and implement the Dispose method...
End Class
You can then go on and implement the IDisposble interface to ensure that you release the resources.
Ok, I am not sure if I have the right library. But I found this Nuget package: OpenNETCF.MQTT which seems to have the class you are using.
I would do it this way
Public Class MyServerClass
Implements IDisposable
Public myMQTTclient As MQTTClient
'Private Sub Ruptela_Server(sender As Object, e As EventArgs) Handles MyBase.Load
' ' <some code>
' StartMQTT()
' ' <some more code>
' ' MQTT_Publish(.....)
'End Sub
Public Sub New(brokerHostName As String)
myMQTTclient = New MQTTClient(brokerHostName)
End Sub
Public Function StartMQTT()
' Establish a connection
Dim code As Byte
Try
code = myMQTTclient.Connect(MQTT_ClientID)
Catch ex As Exception
'<error handling code>
End Try
Return code
End Function
Public Sub MQTT_Publish(ByVal DeviceID As String, ByVal Channel As String, ByVal ChannelType As String, ByVal Value As String, ByVal Unit As String)
Dim myTopic As String = "MyTopic"
Dim myPayload As String = "My Payload"
Dim msgId As UShort = myMQTTclient.Publish(myTopic, Encoding.UTF8.GetBytes(myPayload), MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE, False)
End Sub
#Region "IDisposable Support"
Private disposedValue As Boolean
Protected Overridable Sub Dispose(disposing As Boolean)
If Not disposedValue Then
If disposing Then
myMQTTclient.Dispose()
End If
End If
disposedValue = True
End Sub
Public Sub Dispose() Implements IDisposable.Dispose
Dispose(True)
End Sub
#End Region
End Class
And now you can see the usage when IDisposable is implemented, in a Using block:
Module Module1
Sub Main()
Using myserver As New MyServerClass("www.myserv.com")
myserver.StartMQTT()
myserver.MQTT_Publish(...)
End Using
End Sub
End Module
This makes it so your object is only in scope in the Using, and the object's Dispose method will automatically be called on End Using
I don't know what the base class was originally and why this was declared Private Sub Ruptela_Server(sender As Object, e As EventArgs) Handles MyBase.Load. It seems like it was possibly a form? You should keep your server code separate from Form code if that was the case. I suppose you could paste the Using into your form load, but then you would be blocking your UI thread. The referenced library has Async support so it might be a good idea to leverage that if coming from a UI.
I've made many assumptions, so I'll stop to let you comment and see how close relevant my answer is.
i wrote a program reading a com port for a signal, everything was working fine, but they wanted to make the application a service so i swapped the application type to 'windows service' and created a class and put everything in the form in there and i called the class in my Main() in the startup module. the line,
Me.Invoke(New myDelegate(AddressOf UPdateVariable), New Object() {})
in the class has invoke in red saying that, "'Invoke, is not a member of Moisture.Moisture.'" and the "Me" part of that line is no longer greyed out as it was in the form. it worked before dont know what made the difference.
this is the whole code for that class
Imports System
Imports System.IO.Ports
Imports System.Net.Mime
Public Class Moisture
Dim WithEvents serialPort As New IO.Ports.SerialPort
Public Delegate Sub myDelegate()
Public RawString As New System.Text.StringBuilder
Public value As String
Public Sub StartListening()
If serialPort.IsOpen Then
serialPort.Close()
End If
Try
With serialPort
.PortName = "COM3"
.BaudRate = 9600
.Parity = Parity.None
.StopBits = StopBits.One
.DataBits = 8
.Handshake = Handshake.None
.RtsEnable = True
End With
serialPort.Open()
Catch ex As Exception
End Try
End Sub
Private Sub serialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived
Me.Invoke(New myDelegate(AddressOf UPdateVariable), New Object() {})
End Sub
Public Sub UPdateVariable()
With RawString
.Append(serialPort.ReadLine())
End With
If RawString.ToString().Count(Function(x As Char) x = "%"c) = 2 Then
PiTagUpdater(StringParser(RawString.ToString()))
RawString.Clear()
End If
End Sub
Public Function StringParser(RawString As String) As String
Dim Moisture = RawString
Dim value As String
Dim values As String() = Moisture.Split(New Char() {":"c})
value = values(values.Length - 1).Trim({" "c, "%"c})
Return value
End Function
Private Sub PiTagUpdater(Value As Decimal)
Try
Dim piserver As New PCA.Core.PI.PIServer(PCA.Core.Globals.Applications.Application("GENERAL").ConfigValues.ConfigValue("PI_SERVER_NAME").StringValue, PCA.Core.Globals.Applications.Application("GENERAL").ConfigValues.ConfigValue("PI_SERVER_UID").GetDeCryptedStringValue, PCA.Core.Globals.Applications.Application("GENERAL").ConfigValues.ConfigValue("PI_SERVER_PASSWD").GetDeCryptedStringValue, True)
Dim TimeStamp As DateTime = FormatDateTime(Now)
Dim RapidRingCrush = "M1:RapidRingCrush.T"
Try
piserver.WriteValue(RapidRingCrush, Value, TimeStamp)
Catch ex As Exception
MessageBox.Show("Error occured locating Pi Tag", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Application.Exit()
End Try
Catch ex As Exception
MessageBox.Show("Cannot connect to Pi Server")
End Try
End Sub
End Class
Me refers to the current object, in this case the instance of your class. Your class doesn't have an Invoke() method (like the error says), though anything that derives from System.Windows.Forms.Control does (for instance a Form).
Control.Invoke() is used to move the execution of a method to the same thread that the control was created on. This is used to achieve thread-safety.
Since you switched to a service it is fair to assume that you do not have a user interface, thus there's no need to invoke. Removing the Invoke() call and calling the method manually should be enough:
Private Sub serialPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort.DataReceived
UPdateVariable()
End Sub
EDIT:
As LarsTech says, you also have to switch the message boxes to some kind of logging methods. A Windows Service usually runs under a different account, which means that it cannot display a user interface to the current user.
I have been creating a single instance application using a Mutex.
In the Sub Main code, the app checks to see if it is the first instance, if so it starts the form (called MainForm). The MainForm creates an asynchronous named pipe server to receive arguments passed from a new instance.
If the app is not the first instance, Sub Main creates a named pipe client, sends the command line arguments through to the first app, and proceeds to exit.
The application is tab-based, and each command line argument is a file path, which is used to create the tab. The argument is received (I can MsgBox() it), but when I try to pass it as an argument to the control I'm creating, nothing happen
Pipe classes:
Namespace Pipes
' Delegate for passing received message back to caller
Public Delegate Sub DelegateMessage(Reply As String)
Public Class PipeServer
Public Event PipeMessage As DelegateMessage
Private _pipeName As String
Public Sub Listen(PipeName As String)
Try
' Set to class level var so we can re-use in the async callback method
_pipeName = PipeName
' Create the new async pipe
Dim pipeServer As New NamedPipeServerStream(PipeName, PipeDirection.[In], 1, PipeTransmissionMode.[Byte], PipeOptions.Asynchronous)
' Wait for a connection
pipeServer.BeginWaitForConnection(New AsyncCallback(AddressOf WaitForConnectionCallBack), pipeServer)
Catch oEX As Exception
Debug.WriteLine(oEX.Message)
End Try
End Sub
Private Sub WaitForConnectionCallBack(iar As IAsyncResult)
Try
' Get the pipe
Dim pipeServer As NamedPipeServerStream = DirectCast(iar.AsyncState, NamedPipeServerStream)
' End waiting for the connection
pipeServer.EndWaitForConnection(iar)
Dim buffer As Byte() = New Byte(254) {}
' Read the incoming message
pipeServer.Read(buffer, 0, 255)
' Convert byte buffer to string
Dim stringData As String = Encoding.UTF8.GetString(buffer, 0, buffer.Length)
Debug.WriteLine(stringData + Environment.NewLine)
' Pass message back to calling form
RaiseEvent PipeMessage(stringData)
' Kill original sever and create new wait server
pipeServer.Close()
pipeServer = Nothing
pipeServer = New NamedPipeServerStream(_pipeName, PipeDirection.[In], 1, PipeTransmissionMode.[Byte], PipeOptions.Asynchronous)
' Recursively wait for the connection again and again....
pipeServer.BeginWaitForConnection(New AsyncCallback(AddressOf WaitForConnectionCallBack), pipeServer)
Catch
Return
End Try
End Sub
End Class
Class PipeClient
Public Sub Send(SendStr As String, PipeName As String, Optional TimeOut As Integer = 1000)
Try
Dim pipeStream As New NamedPipeClientStream(".", PipeName, PipeDirection.Out, PipeOptions.Asynchronous)
' The connect function will indefinitely wait for the pipe to become available
' If that is not acceptable specify a maximum waiting time (in ms)
pipeStream.Connect(TimeOut)
Debug.WriteLine("[Client] Pipe connection established")
Dim _buffer As Byte() = Encoding.UTF8.GetBytes(SendStr)
pipeStream.BeginWrite(_buffer, 0, _buffer.Length, AddressOf AsyncSend, pipeStream)
Catch oEX As TimeoutException
Debug.WriteLine(oEX.Message)
End Try
End Sub
Private Sub AsyncSend(iar As IAsyncResult)
Try
' Get the pipe
Dim pipeStream As NamedPipeClientStream = DirectCast(iar.AsyncState, NamedPipeClientStream)
' End the write
pipeStream.EndWrite(iar)
pipeStream.Flush()
pipeStream.Close()
pipeStream.Dispose()
Catch oEX As Exception
Debug.WriteLine(oEX.Message)
End Try
End Sub
End Class
End Namespace
MainForm logic:
#Region "Pipes"
Public ArgumentPipe As New Pipes.PipeServer
Public Sub RecievedMessage(reply As String)
GetMainformHook.Invoke(MySTDelegate, reply)
End Sub
Public Sub InitializeServer()
AddHandler ArgumentPipe.PipeMessage, AddressOf RecievedMessage
ArgumentPipe.Listen(_pipename)
End Sub
Public Delegate Sub RecievedMessageDel(txt As String)
Public MySTDelegate As RecievedMessageDel = AddressOf SetText
Public Sub SetText(txt)
MsgBox(txt)
TabStrip1.AddTab(txt.ToString) 'PROBLEM OCCURS HERE
End Sub
Public Shared Function GetMainformHook() As MainForm
Return Application.OpenForms("MainForm")
End Function
Public Shared Function GetTabControl() As TabStrip
Return CType(Application.OpenForms("MainForm"), MainForm).TabStrip1
End Function
Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
InitializeServer()
End Sub
#End Region
In Sub Main when sending argument:
Dim _pipeClient = New Pipes.PipeClient()
If cmdArgs.Length > 0 Then
For i = 0 To cmdArgs.Length - 1
_pipeClient.Send(cmdArgs(i), _pipename, 1000)
Next
End If
_pipename is a global string like "myappv6"
Am I missing something?
I'm thinking this has something to do with cross threading, but can't pinpoint where to fix it.
Thanks
I'm having a hard time trying to understand what seems to be a random throwing of cross-thread exceptions.
Examples
When invoked in a different thread, why does this work:
Dim text As String = Me.Text
While this will throw an exception:
Me.Text = "str"
What makes it even stranger is that the following do work:
Dim text As String = Me.ctl.Margin.ToString() : Me.ctl.Margin = New Padding(1, 2, 3, 4)
Dim text As String = Me.ctl.MyProp : Me.MyProp = "str"
Note
Yes, I know that I could just invoke the property like this:
Me.Invoke(Sub() Me.Text = "str")
Question
So when can I expect a cross-thread exception?
Code
This is the code i used to test the Me.Text property:
Public Class Form1
Public Sub New()
Me.InitializeComponent()
Me.ctl = New Control()
Me.ctl.Text = "test_control"
Me.Controls.Add(Me.ctl)
End Sub
Private Sub TestGet(sender As Object, e As EventArgs) Handles Button1.Click
Dim t As New Thread(AddressOf Me._Proc)
t.Start(TESTTYPE.GET)
End Sub
Private Sub TestSet(sender As Object, e As EventArgs) Handles Button2.Click
Dim t As New Thread(AddressOf Me._Proc)
t.Start(TESTTYPE.SET)
End Sub
Private Sub _Proc(tt As TESTTYPE)
Dim text As String = String.Empty
Dim [error] As Exception = Nothing
Try
If (tt = TESTTYPE.GET) Then
text = Me.ctl.Text
ElseIf (tt = TESTTYPE.SET) Then
Me.ctl.Text = "test"
End If
Catch ex As Exception
[error] = ex
End Try
Me.Invoke(Sub() Me._Completed(tt, text, [error]))
End Sub
Private Sub _Completed(tt As TESTTYPE, text As String, ByVal [error] As Exception)
If ([error] Is Nothing) Then
If (tt = TESTTYPE.GET) Then
MessageBox.Show(String.Concat("Success: '", text, "'"), tt.ToString(), MessageBoxButtons.OK, MessageBoxIcon.Information)
ElseIf (tt = TESTTYPE.SET) Then
MessageBox.Show("Success", tt.ToString(), MessageBoxButtons.OK, MessageBoxIcon.Information)
End If
Else
MessageBox.Show([error].Message, tt.ToString(), MessageBoxButtons.OK, MessageBoxIcon.Error)
End If
End Sub
Private ReadOnly ctl As Control
Private Enum TESTTYPE
[GET] = 0
[SET] = 1
End Enum
End Class
Edit
This will not throw an exception:
Public Event TestChanged As EventHandler
Public Property Test() As String
Get
Return Me.m_test
End Get
Set(value As String)
If (value <> Me.m_test) Then
Me.m_test = value
Me.Invalidate()
RaiseEvent TestChanged(Me, EventArgs.Empty)
End If
End Set
End Property
the main time a cross-thread exception occurs when you do something that would cause an event to fire from the non-UI thread that affects the UI thread; So reading a property can be fine, but writing the property of a control would cause it to repaint (at the very least), hence the exception.
Of course, other vendors may have used the exception for other scenarios where it is not safe to access from a different thread
So when can I expect a cross-thread exception?
Well, GUI in .Net are created in STA which means that only the thread that create the control can update it this has to do with Thread-safe concept. for this reasons when you start another thread and try to access the control which is owned by the main thread you will get an invalidOperationException
So when can I expect a cross-thread exception?
Really simple, when you access some function or property of a control, from a thread which do not have right to access it.
For example, in Window form application when you try to access the button placed on form from a non-ui thread, i.e. not the main thread, (and you have not set any flags manually to allow cross-thread operation)
EDIT As per comment, how can I know I can/can not access a getter/ setter of a property. Where are the access rights defined? you can always be on safe side by querying the control's InvokeRequired property in Windows
Okay, so I did some research myself, and it turns out that the exception originates in the .Handle property of the Control.
<Browsable(False), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), DispId(-515), SRDescription("ControlHandleDescr")> _
Public ReadOnly Property Handle As IntPtr
Get
If ((Control.checkForIllegalCrossThreadCalls AndAlso Not Control.inCrossThreadSafeCall) AndAlso Me.InvokeRequired) Then
Throw New InvalidOperationException(SR.GetString("IllegalCrossThreadCall", New Object() {Me.Name}))
End If
If Not Me.IsHandleCreated Then
Me.CreateHandle()
End If
Return Me.HandleInternal
End Get
End Property
System.Windows.Forms.resources:
IllegalCrossThreadCall=Cross-thread operation not valid: Control '{0}' accessed from a thread other than the thread it was created on.
So I believe the answer would be something like this:
Whenever the handle of a control is invoked from a different thread.
(I'll give you all a vote up as all the answers are relevant towards cross-threading.)
The following code will throw an exception:
Public Class Form1
Private Sub Test(sender As Object, e As EventArgs) Handles Button1.Click
Dim t As New Thread(AddressOf Me._Proc)
t.Start()
End Sub
Private Sub _Proc(id As Integer)
Dim [error] As Exception = Nothing
Try
Dim p As IntPtr = Me.Handle
Catch ex As Exception
[error] = ex
End Try
Me.Invoke(Sub() Me._Completed([error]))
End Sub
Private Sub _Completed(ByVal [error] As Exception)
If ([error] Is Nothing) Then
MessageBox.Show("Success", Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Information)
Else
MessageBox.Show([error].Message, Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Error)
Me.tbDescription.Text = [error].Message
End If
End Sub
End Class