Cross-thread operation not valid

[tassa]

Hello,

I'm having trouble trying to update the Form1's text, I've tried the next code, but it throws this exception:

Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on.

What am I doing wrong?

Private Sub PercentCompleted(ByVal progress As Integer) Handles PercentDone.Progress
        Dim deleg As New ProgressDone(AddressOf UpdateProgress)
        Me.ProgressBar1.Invoke(deleg, progress)
 
    End Sub
 
    Private Sub UpdateProgress(ByVal e As Object)
        Me.ProgressBar1.Value = CInt(e)
        Me.Text = CStr(e) & "% Completed"
    End Sub

Thanks in advance!!

[.paul.]

try this:

Private Delegate Sub UpdateProgressCallback(ByVal e As Object)
 
Private Sub UpdateProgress(ByVal e As Object)
    If ProgressBar1.InvokeRequired Then
        ProgressBar1.Invoke(New UpdateProgressCallback(AddressOf UpdateProgress),e)
    Else    
        If me.InvokeRequired Then
            me.Invoke(New UpdateProgressCallback(AddressOf UpdateProgress),e)
        Else            
            Me.ProgressBar1.Value = CInt(e)
            Me.Text = CStr(e) & "% Completed"
        end if
    end if
End Sub

[tassa]

Hey Paul,

thanks for the fast reply. The progressbar invoke is working great, but it still gives me the Form1 error. (It does change Form1's text, but then it throws the error).

I have no idea of what it could be.

[.paul.]

try invoking the form too

[tassa]

It's telling me to refer to it as Me, instead of Form1.

I'm trying this:

Private Sub PercentCompleted(ByVal e As Integer) Handles PercentDone.Progress
        If Me.ProgressBar1.InvokeRequired Then
            Me.ProgressBar1.Invoke(New UpdateProgressCallBack(AddressOf PercentCompleted), e)
        Else
            If Me.InvokeRequired Then
                Me.Invoke(New UpdateProgressCallBack(AddressOf PercentCompleted), e)
            Else
                If Form1.InvokeRequired Then
                    Form1.Invoke(New UpdateProgressCallBack(AddressOf PercentCompleted), e)
                End If
                Me.ProgressBar1.Value = e
                Me.Text = CStr(e) & "% Completed"
            End If
        End If
    End Sub

[formlesstree4]

Why not use a Background Worker...or is that not possible? That would help handle any of your Cross-Threading problems, but I assume you've already tried that path?

[tassa]

The reason why I'm not using a BW is because the process is being done by a class, so I had the class raise an event to report the progress and then I would report it the old-fashioned way.

[formlesstree4]

Oho, that explains why then. I have nothing else to contribute unfortunately .