Threading, Invoke, Delegate and MethodInvoker... - Visual Basic Discussion Boards

In that case I would suggest you should have different subs. Or better still the types should expose their data content as Properties, which you can then set without needing to check which type it is.

Both of your "type1" and "type2" classes have fields in common. Ok, so those have to be broken out into something that is common between those two types, either an Interface implementation or a base class that they both inherit from.

You will then be able to pass your "type1" and "type2" class instances as either that interface or base class for the method to use. For example, an interface version would look something like:

VB.NET

Public Interface SomeInterface
    Property SomeProperty As String
    Property AnotherProperty As Int
End Interface

And both of your "types" would have to implement the interface:

VB.NET

Public Class Type1 Implements SomeInterface
...
End Class

Public Class Type2 Implements SomeInterface
...
End Class

When you define your method that has to accept instances of these two classes, you use the interface to define the parameter expected:

VB.NET

    Public Sub MyMethod(ByVal parameter As SomeInterface)
End Sub

The method is saying "I need something that implements this interface". It's a contract where the method expects the object passed in as "parameter" to implement a know interface, guaranteeing the properties defined in the interface will be there in the object that is passed in.

When you go to call this method, you're saying this is an instance of Type1, but since it implements this interface, treat this object as this interface type, not as the Type1 class.

VB.NET

    Dim myInstance As New Type1
...
    MyMethod(myInstance)

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Dave Kreskowiak

Easy way is to put those details in their own class, and make that new class part of type1 and type2.

VB

Public Class McBoatFace
    Property Num As Integer
    Property vl As String
End Class
Public Class Type1
    Property Boat As McBoatFace
End Class
Public Class Type2
    Property Boat As McBoatFace
End Class

Sub Marine(Boat As McBoatFace)
    ' access to Boat.Num and Boat.vl
End Sub

A less easy, but cleaner way would be implementing the McBoatface-class as an interface, and to pass the interface to the sub. Another way to make it cleaner is by putting the Boat-property into a new Type0-class, and inherit Type1 and Type2 from it; makes the property appear in both classes.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

The types type1 and type2 are totally different types , but both have the fields that I use on the sub.

I suppose that there is a possible solution - but for this you should give more information about your issue ...
Perhaps you write something more about those 2 types and what is common to them.
In my opinion each of your types derive from Object and so you should be able to identify each type in your method ...
But ... as I wrote before ... more Info required ...

I am creating a tool to delete user profiles by age on all windows 7 and windows 10 devices on our domains. I have it working using this filter ("(objectClass=computer)") but want to refine that to only get windows 7 and windows 10 devices because my department manages desktops/laptops not servers. In order to make the tool more efficient and not attempt to connect to devices I don't have admin access to.

So I tried this filter... mySearcher.Filter = "(&(objectClass=computer)(operatingSystemVersion=*server*))" my thought was to do something like this if OS IsNot Windows Server 2012 or Windows Server 2008 then do something.

I loaded the operatingSystem property but can't get it to display. I have tried it in the datagridview and when that didn't work I just tried to do a consolewriteline and that didn't work either. I want to test my concept before adding the code to use WMI to delete profiles by just displaying the hostname and OS version to make sure it is pulling the information from AD and not giving me servers. Can someone help? Here is the code(I am just working with the v06 domain at the moment):

Dim mySearcher As DirectorySearcher = New DirectorySearcher(enTry)
       mySearcher.PropertiesToLoad.Add("dNSHostName")
       mySearcher.PropertiesToLoad.Add("operatingSystem")
       mySearcher.PropertiesToLoad.Add("operatingSystemVersion")
       mySearcher.Filter = "(&(objectClass=computer)(operatingSystem=*server*))" '("(objectClass=computer)")

       Dim resEnt As SearchResult
       For Each resEnt In mySearcher.FindAll()
           Select Case dMain
               Case "v06"
                   Try

                       hostName = GetProperty(resEnt, "dNSHostName")
                       OSystem = GetProperty(resEnt, "operatingSystem")
                       Dim result1 As Net.NetworkInformation.PingReply = ping.Send(hostName, 1000)
                       If result1.Status = Net.NetworkInformation.IPStatus.Success Then
                           Dim row2 As String() = New String() {hostName, "N/A", OSystem}
                           dgvLocal.Rows.Add(row2)
                       Else
                           My.Computer.FileSystem.WriteAllText("C:\ExodusErrorLog.txt", hostName & " - Device is not pingable!" & vbCrLf & vbCrLf, True)
                       End If
                   Catch ex As Exception
                       My.Computer.FileSystem.WriteAllText("C:\ExodusErrorLog.txt", hostName & " - " & ex.Message & vbCrLf & vbCrLf, True)
                   End Try
               Case "v07.med.va.gov"
           End Select
       Next

modified 25-Dec-18 13:32pm.

Here's an alternative to the solution you seek; get a full list of all the PC's, and then use LINQ to query out the ones that are servers. You may also get a better query from a network-admin; it is querying the AD after all.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

Learning Threading, Invoke, Delegate and MethodInvoker ...

0) I use Visual Basic 2017.
1) I can press Button1 or Button2 randomly: works!
2) After the first round I can only press Button2. Button1 no longer works!
3) Who can indicate IN THE CODE where the error is?
4) I search for information everywhere on the internet, but what exactly Invoke, Delegate and MethodInvoker do, is not completely clear to me … Sigh | :sigh:

5) Thank you …

VB

Public Class Form1

    Dim Number1 As Integer
    Dim Number2 As Integer

    Dim Thread1 As System.Threading.Thread
    Dim Thread2 As System.Threading.Thread

    Private Delegate Sub UpdateLabel1Delegate(ByVal Number1 As Integer)
    Private Delegate Sub UpdateLabel2Delegate(ByVal Number2 As Integer)

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Thread1 = New System.Threading.Thread(AddressOf CountUp)
        Thread1.Start()
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Thread2 = New System.Threading.Thread(AddressOf CountDown)
        Thread2.Start()
    End Sub

    Private Sub CountUp()
        Do Until Number1 = 1000
            Number1 = Number1 + 1
            UpdateLabel1Text(Number1)
        Loop
    End Sub 'CountUp

    Private Sub CountDown()
        Number2 = 1000
        Do Until Number2 = 0
            Number2 = Number2 - 1
            UpdateLabel2Text(Number2)
        Loop
    End Sub 'CountDown

    Private Sub UpdateLabel1Text(ByVal Number1 As Integer)
        If Label1.InvokeRequired Then
            ' This is a cross-thread call, so
            ' invoke a call back to this method.
            Me.BeginInvoke(New UpdateLabel1Delegate(AddressOf UpdateLabel1Text), Number1)
        Else
            ' We're being called on the UI thread, so just update the label.
            Label1.Text = Number1
            Me.Refresh()
        End If
    End Sub

    Private Sub UpdateLabel2Text(ByVal Number2 As Integer)
        If Label2.InvokeRequired Then
            ' This is a cross-thread call, so
            ' invoke a call back to this method.
            Me.BeginInvoke(New UpdateLabel2Delegate(AddressOf UpdateLabel2Text), Number2)
        Else
            ' We're being called on the UI thread, so just update the label.
            Label2.Text = Number2
            Me.Refresh()
        End If
    End Sub

End Class

You're initializing the number in one sub, but not the other.

VB

Private Sub CountUp()
        Number1 = 0
        Do Until Number1 = 1000
            Number1 = Number1 + 1
            UpdateLabel1Text(Number1)
        Loop
    End Sub 'CountUp

Enjoy the festivities and keep on learning, you're doing well Thumbs Up | :thumbsup:

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

Thanks Eddy!

Very, very stupid of me D'Oh! | :doh:

!!

Eric

Member 11112814 wrote:
Very, very stupid of me !!

It's not, we all have those moments; you're searching for an error, and there clearly is none. I wasn't searching for one, just looking for the difference that you told me would be there.

It was a good formulated question with description of expected and actual results. Thumbs Up | :thumbsup:

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

My final assigment is about client server using timer. if client and server are connected with 30 minute then communication between clienrt and server will be disconnect. but i couldnt find timer function on internet. i have finished with client serverbut not yet to part using timer. if u can help me, please reply me as soon as possible.

Thank You.

modified 22-Dec-18 22:18pm.

See Timer Class (System.Timers) | Microsoft Docs[^] and Stopwatch Class (System.Diagnostics) | Microsoft Docs[^].

thakn you for your reply Smile | :)

Unless you love getting spam emails, NEVER post your email address in a public forum. I suggest you edit your post and remove it now.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.

Dave Kreskowiak

I'm creating an project which can show me the complete list of "Installed" software in my system and "Uninstalled" them please help me to find.

Your question/problem is not clear. Please read the pinned post at the top of the forum How to get an answer to your question - Visual Basic Discussion Boards[^]

You can already do it in Control Panel. But see also vb.net list installed applications - Google Search[^].

There is no "complete" list; not every application registers an uninstaller with Windows.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

The SQL code am using is

Private Sub Command8_Click()
Dim SQL As String
    
    SQL = "SELECT tblVisit.PatientID, tblPatients.Firstname, tblPatients.Lastname" _
        & "DateDiff('yyyy',[tblPatients]![Birthday],Now()) AS Age, tblVisit.[Date Visit]" _
        & "tblVisit.Diagnosis" _
        & "[First Name] &  ' ' & [Last Name] AS [Prescriber Names] FROM tblPatients INNER JOIN (tblDoctor INNER JOIN tblVisit ON tblDoctor.DoctorID = tblVisit.DoctorID) ON tblPatients.PatientID = tblVisit.PatientID" _
        & "WHERE [Firstname] = '" & Me.txtKeywords & "' "
        
    Me.subClientList.Form.RecordSource = SQL
    Me.subClientList.Form.Requery
     
End Sub

The error that is coming up is..
The error is runtime error '3075'
syntax error (missing operator) in query expression 'tblvist'.[DateVisit]tblVist.Diagnosis[First Name]& ' ' [Last Name]'

The

[First Name]& ' ' [Last Name]'

are from a table prescribers and the

tblVist.Diagnosis

is an attachment column in the table visit and the

tblvist'.[DateVisit]tblVist

is a column of visit dates

I think you need a comma after each item.

Thanks alot for your input. Because of you. I managed to troubleshoot and I have got it working. thanks alot

You're using string concatenation to build the query. This alone is a bad idea as you are very vulnerable to making mistakes and you open the database up to being destroyed due to SQL Injection attacks.

Your code looks like this:

SQL = "SELECT tblVisit.PatientID, tblPatients.Firstname, tblPatients.Lastname" _
        & "DateDiff('yyyy',[tblPatients]![Birthday],Now()) AS Age, tblVisit.[Date Visit]" _
        & "tblVisit.Diagnosis" _
        & "[First Name] &  ' ' & [Last Name] AS [Prescriber Names] FROM tblPatients INNER JOIN (tblDoctor INNER JOIN tblVisit ON tblDoctor.DoctorID = tblVisit.DoctorID) ON tblPatients.PatientID = tblVisit.PatientID" _
        & "WHERE [Firstname] = '" & Me.txtKeywords & "' "

This results in a query string that looks like this. Examine this query statement closely and you're going to find lots of problems. You're missing spaces between words and messed up the concatenation in places.

SELECT tblVisit.PatientID, tblPatients.Firstname, tblPatients.LastnameDateDiff('yyyy',[tblPatients]![Birthday],Now()) AS Age, tblVisit.[Date Visit]tblVisit.Diagnosis[First Name] &  ' ' & [Last Name] AS [Prescriber Names] FROM tblPatients INNER JOIN (tblDoctor INNER JOIN tblVisit ON tblDoctor.DoctorID = tblVisit.DoctorID) ON tblPatients.PatientID = tblVisit.PatientIDWHERE [Firstname] = 'SqlInjectionAttack' "

Now, Google for "SQL Injection Attack" to find out why what you did was so wrong, then Goggle for "VB.NET SQL parameterized queries" to find out what to do about it.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.

Dave Kreskowiak

Public Class Form1
    Dim attempt As Integer
    Private Sub BtnLogIn_Click(sender As Object, e As EventArgs) Handles BtnLogIn.Click
        If CBUser.Text = "Mineomyn" And TBPass.Text = "lemsilog" Then
            MsgBox("Log in successful!", MsgBoxStyle.Information)
            TBPass.Clear()
            GBAddons.Enabled = True
            GBPizza.Enabled = True
            RichTextBox1.Enabled = True
            BtnCalculate.Enabled = True
            BtnCompleteOrder.Enabled = True
            BtnClearOrder.Enabled = True
            TBAmount.Enabled = True
            TBChange.Enabled = True
            TBTotal.Enabled = True
            BtnChange.Enabled = True

        ElseIf CBUser.Text = "Lemsilog" And TBPass.Text = "lemsilog" Then
            MsgBox("Log in successful!", MsgBoxStyle.Information)
            TBPass.Clear()
            GBAddons.Enabled = True
            GBPizza.Enabled = True
            RichTextBox1.Enabled = True
            BtnCalculate.Enabled = True
            BtnCompleteOrder.Enabled = True
            BtnClearOrder.Enabled = True
            TBAmount.Enabled = True
            TBChange.Enabled = True
            TBTotal.Enabled = True
            BtnChange.Enabled = True

        ElseIf CBUser.Text = "Lemzipon" And TBPass.Text = "lemsilog" Then
            MsgBox("Log in successful!", MsgBoxStyle.Information)
            TBPass.Clear()
            GBAddons.Enabled = True
            GBPizza.Enabled = True
            RichTextBox1.Enabled = True
            BtnCalculate.Enabled = True
            BtnCompleteOrder.Enabled = True
            BtnClearOrder.Enabled = True
            TBAmount.Enabled = True
            TBChange.Enabled = True
            TBTotal.Enabled = True
            BtnChange.Enabled = True

        Else attempt = attempt + 1

        End If

        If attempt = 1 Then
            MsgBox("Incorrect user or pass. Attempts left: 2", MsgBoxStyle.Exclamation)
            TBPass.Clear()
            GBAddons.Enabled = False
            GBPizza.Enabled = False
            RichTextBox1.Enabled = False

        ElseIf attempt = 2 Then
            MsgBox("Incorrect user or pass. Attempts left: 1", MsgBoxStyle.Exclamation)
            TBPass.Clear()
            GBAddons.Enabled = False
            GBPizza.Enabled = False
            RichTextBox1.Enabled = False

        ElseIf attempt = 3 Then
            MsgBox("Incorrect user or pass. You have reached maximum attempts to log in. Try again later.", MsgBoxStyle.Critical)
            TBPass.Clear()
            GBAddons.Enabled = False
            GBPizza.Enabled = False
            RichTextBox1.Enabled = False
            BtnLogIn.Enabled = False
        End If
    End Sub

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        GBPizza.Enabled = False
        GBAddons.Enabled = False
        RichTextBox1.Enabled = False
        BtnCalculate.Enabled = False
        BtnCompleteOrder.Enabled = False
        BtnClearOrder.Enabled = False
        TBAmount.Enabled = False
        TBChange.Enabled = False
        TBTotal.Enabled = False
        BtnChange.Enabled = False
    End Sub

    Private Sub calculate()
        Dim cost As Double
        Dim order As String

        If Radsmall.Checked Then
            cost = Radsmall.Tag
            order = "18 inch"

        ElseIf Radmedium.Checked Then
            cost = Radmedium.Tag
            order = "24 inch"

        Else
            cost = Radlarge.Tag
            order = "28 inch"
        End If

        If CB15Coke.Checked Then cost += CB15Coke.Tag
        If CB1Coke.Checked Then cost += CB1Coke.Tag
        If CBCrust.Checked Then cost += CBCrust.Tag
        If CBextracheese.Checked Then cost += CBextracheese.Tag
        If CBmushroom.Checked Then cost += CBmushroom.Tag
        If CBsingledrink.Checked Then cost += CBsingledrink.Tag

        TBTotal.Text = cost

        Dim display As String = "You order a " & order

        If ComboPizza.Text = "Pepperoni" Then display += " pepperoni pizza"
        If ComboPizza.Text = "4 Cheese" Then display += " 4 cheese pizza"
        If ComboPizza.Text = "All meat" Then display += " all meat pizza"
        If ComboPizza.Text = "Hawaiian" Then display += " hawaiian pizza"
        If ComboPizza.Text = "Classic Italian" Then display += " classic italian pizza"
        If ComboPizza.Text = "New York Style" Then display += " New York style pizza"
        If ComboPizza.Text = "Pure Beef" Then display += " pure beef pizza"

        If CB15Coke.Checked Then display += " with 1.5L Coke"
        If CB1Coke.Checked Then display += " with 1L Coke"
        If CBCrust.Checked Then display += " with tuff crust"
        If CBextracheese.Checked Then display += " with extra cheese"
        If CBmushroom.Checked Then display += " with mushroom"
        If CBsingledrink.Checked Then display += " with single drink"

        Me.RichTextBox1.Text = display

    End Sub

    Private Sub BtnCalculate_Click(sender As Object, e As EventArgs) Handles BtnCalculate.Click
        calculate()
    End Sub

    Private Sub BtnCancelOrder_Click(sender As Object, e As EventArgs) Handles BtnClearOrder.Click
        TBAmount.Clear()
        TBChange.Clear()
        TBTotal.Clear()
        Radlarge.Checked = False
        Radmedium.Checked = False
        Radsmall.Checked = False
        CB15Coke.Checked = False
        CB1Coke.Checked = False
        CBCrust.Checked = False
        CBextracheese.Checked = False
        CBmushroom.Checked = False
        CBsingledrink.Checked = False
        ComboPizza.Text = ""
        Me.RichTextBox1.Clear()

    End Sub

    Private Sub BtnChange_Click(sender As Object, e As EventArgs) Handles BtnChange.Click

        TBChange.Text = Val(TBTotal.Text - TBAmount.Text)
    End Sub

    Private Sub BtnCompleteOrder_Click(sender As Object, e As EventArgs) Handles BtnCompleteOrder.Click
        MsgBox("Order is complete. Your order will be delivered to you within 45 minutes. Thank you!")

    End Sub
End Class

The "Calculate Order" button will do the total order. Then I have to manually put the amount on the "Amount Paid" textbox to get the change. Now, what I wanted to do is to assign the enter key so that I can just press enter after typing the amount and don't have to hover the mouse and click the "Amount Paid" button. I don't know the codes for it, and where should i put the codes, on the textbox or on the button? The accept button property is already used on my "Log in" button. Please help me. xD Thanks in advance!

See TextBox.AcceptsReturn Property (System.Windows.Forms) | Microsoft Docs[^].