[2005] Cross-thread operation not valid

[Ajx123]

Hello friend Need help for the Following code .




Imports System.Threading

Public Class Form1
'txt1 = TextBox1
'txt2 = TextBox2
Dim counter1 As New Counter
Dim thread1 As New System.Threading.Thread(AddressOf counter1.count)
Private Sub BtnStartCounting_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnStartCounting.Click
txt2.Clear()
counter1.countTo = CInt(txt1.Text)
AddHandler counter1.FinishedCounting, AddressOf FinishedCountingEventHandler
thread1.Start()
End Sub

Public Sub FinishedCountingEventHandler(ByVal Count As Integer)
txt2.Text = Count.ToString
End Sub
End Class

Public Class Counter
Public countTo As Integer
Public Event FinishedCounting(ByVal Numberofmarches As Integer)
Public Sub count()
Dim loopIndex, Total As Integer
Total = 0
For loopIndex = 1 To countTo
Total += 1
Next loopIndex
RaiseEvent FinishedCounting(Total)
End Sub
End Class




While Executing the Programm. Getting Following Error.
-----
Cross-thread operation not valid: Control 'txt2' accessed from a thread other than the thread it was created on.


Help to to solve the Error.

[Shardox]

Use a delegate to access the control from another thread:

Imports System.Threading

Public Class Form1

    Dim counter1 As New Counter
    Dim thread1 As New System.Threading.Thread(AddressOf counter1.count)
    Delegate Sub FinishedCountingCallback(ByVal Count As Integer)

    Private Sub BtnStartCounting_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnStartCounting.Click
        txt2.Clear()
        counter1.countTo = CInt(txt1.Text)
        AddHandler counter1.FinishedCounting, AddressOf FinishedCountingEventHandler
        thread1.Start()
    End Sub

    Public Sub FinishedCountingEventHandler(ByVal Count As Integer)
        ' InvokeRequired required compares the thread ID of the
        ' calling thread to the thread ID of the creating thread.
        ' If these threads are different, it returns true.
        If Me.txt2.InvokeRequired Then
            Dim d As New FinishedCountingCallback(AddressOf FinishedCountingEventHandler)
            Me.Invoke(d, Count)
        Else
            txt2.Text = Count.ToString
        End If
    End Sub
End Class

Public Class Counter
    Public countTo As Integer
    Public Event FinishedCounting(ByVal Numberofmarches As Integer)
    Public Sub count()
        Dim loopIndex, Total As Integer
        Total = 0
        For loopIndex = 1 To countTo
            Total += 1
        Next loopIndex
        RaiseEvent FinishedCounting(Total)
    End Sub
End Class

[Ajx123]

Thank You Shardox Cross-thread operation not valid is solved

[archymaseno]

One of the coolest and to the point post ......Thanx men