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[Rhez]

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My code is like this

Code: Select all

Sub Note()
        Try
            Dim TXT1 As String = "http://www.myurl.pro"
            Dim Read1 As StreamReader = New StreamReader(WebClient.OpenRead(TXT1))
            Dim STR1 As String = Read1.ReadToEnd
            Note.Text = STR1
Catch ex As Exception
            Note.Text = "ERROR"
        End Try
End Sub
 Dim Note = New Thread(Sub() Note())

Then on Form Load Event :
Note.Start()

The url there are just a replace of my original url.

I hope someone will help me out of this. Thanks in advance cooll;

[comathi]

As explained in This StackOverflow thread, controls created from the UI thread can only be accessed through the UI thread (hence the error).

The link also offers a possible solution to your problem, ie. checking if Note() is being called from another thread, and if so calling the appropriate methods from the UI thread itself cooll;

[Rhez]

I'm sorry for being a newbie.
But, can u give me the exact way/code. I'm new with multi-threading nor multi-threading with invoking.

[comathi]

I'm also a noob with multi-threading in VB.NET, but from this link, this is what I understand should be used:

Code: Select all

Dim Note = New Thread(AddressOf Note)

Private Delegate Sub NoteDelegate()
Private Sub Note()
    If Me.InvokeRequired Then
        Me.Invoke(New NoteDelegate(AddressOf Note))
    Else
        Try
            Dim TXT1 As String = "http://www.myurl.pro"
            Dim Read1 As StreamReader = New StreamReader(WebClient.OpenRead(TXT1))
            Dim STR1 As String = Read1.ReadToEnd
            Note.Text = STR1
        Catch ex As Exception
            Note.Text = "ERROR"
        End Try
    End If
End Sub

And then of course, as before, you'd have Note.Start() in Form.Load

[SumCode]

I'm also a noob with multi-threading in VB.NET, but from this link, this is what I understand should be used:

Code: Select all

Dim Note = New Thread(AddressOf Note)

Private Delegate Sub NoteDelegate()
Private Sub Note()
    If Me.InvokeRequired Then
        Me.Invoke(New NoteDelegate(AddressOf Note))
    Else
        Try
            Dim TXT1 As String = "http://www.myurl.pro"
            Dim Read1 As StreamReader = New StreamReader(WebClient.OpenRead(TXT1))
            Dim STR1 As String = Read1.ReadToEnd
            Note.Text = STR1
        Catch ex As Exception
            Note.Text = "ERROR"
        End Try
    End If
End Sub

And then of course, as before, you'd have Note.Start() in Form.Load

You don't have to create a new delegate to invoke your method. You could use a pre-existing delegate called the MethodInvoker

[comathi]

#SumCode

Care to post a snippet as to how that would work for what #Rhez is trying to do? I haven't touched VB in a while and I haven't done much multithreading, so this is not something I'm familiar with

[SumCode]

So what I am saying is that instead of creating a new delegate (in your case 'NoteDelegate') you can use a pre made delegate called MethodInvoker. So where you wrote

Code: Select all

Me.Invoke(New NoteDelegate(AddressOf Note))

one could write

Code: Select all

Invoke(New MethodInvoker(AddressOf Note))

Not that big of a deal though. One could use either create a new delegate if one pleases or just use the MethodInvoker (or Action) delegate.