Cross-thread operation not valid 2

[mancroft]

Cross-thread operation not valid

Hello

i am trying to put a counter variable created in a thread into a label and am getting "Cross-thread operation not valid".

Is there an easy way around this?

Thank you.

 

[chrissie1]

if you look at th help you get when you get this error (you are working in 2005 aren't you) then it will give you at least 5 options. One of them being a delegate with begininvoke and invokerequired. try that.

Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]

 

[mancroft]

Thanks for the hint chrissie1.

I found this which is quite helpful:

http://www.informit.com/guides/content.asp?g=dotnet&seqNum=194&rl=1

 

[chrissie1]

Actually a very interesting site. So have a star.

Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]

 

[mancroft]

Here is some code that is a lot simpler to understand... and it works:

Imports System.Threading

Public Class Form1

    Private Delegate Sub DelAddItem(ByVal Message As String)

    Private Sub btnButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim T1 As Thread

        T1 = New Thread(AddressOf Thread1Work)
        T1.IsBackground = True
        T1.Start()

    End Sub

    Protected Sub Thread1Work()

        Dim del As DelAddItem
        Dim o(0) As Object
        del = New DelAddItem(AddressOf DelegateWork)
        Dim I As Integer
        For I = 0 To 100
            o(0) = "Hello " & I.ToString
            Thread.Sleep(700)
            Label1.Invoke(del, o)
        Next

    End Sub

    Private Sub DelegateWork(ByVal Message As String)

        Label1.Text = Message

    End Sub

End Class

 

[chrissie1]

And you can make it even more simple by doing this.

Imports System.Threading

[Blue]Public[/Blue] [Blue]Class[/Blue] Form1

    [Blue]Private[/Blue] Delegate [Blue]Sub[/Blue] DelAddItem([Blue]ByVal[/Blue] Message [Blue]As[/Blue] [Blue]String[/Blue])

    [Blue]Private[/Blue] [Blue]Sub[/Blue] btnButton1_Click([Blue]ByVal[/Blue] sender [Blue]As[/Blue] System.Object, [Blue]ByVal[/Blue] e [Blue]As[/Blue] System.EventArgs) [Blue]Handles[/Blue] Button1.Click

        [Blue]Dim[/Blue] T1 [Blue]As[/Blue] Thread
for inttemp as integer = 0 to 100
        T1 = [Blue]New[/Blue] Thread(AddressOf Thread1Work([Red]"Hello"[/Red] & inttemp)
        T1.IsBackground = [Blue]True[/Blue]
        T1.Start()
next

    [Blue]End[/Blue] [Blue]Sub[/Blue]

    [Blue]Protected[/Blue] [Blue]Sub[/Blue] Thread1Work(byval message as string)
        if me.label1.invokerequired then
            [Blue]Dim[/Blue] del [Blue]As[/Blue] DelAddItem = [Blue]New[/Blue] DelAddItem(AddressOf threadWork)
            me.invoke(del,new object() {message)
       else
            label1.text = message
       end if
    [Blue]End[/Blue] [Blue]Sub[/Blue]
[Blue]End[/Blue] [Blue]Class[/Blue]

untested but should work

Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]