vb.net accessed from a thread other than the thread it was created on

问题

I am trying to set text to label Label_caller.Text = phone_number and I get this error: "System.InvalidOperationException: Cross-thread operation not valid: Control 'Label_caller' accessed from a thread other than the thread it was created on." How do I overcome this problem? How do I use keyword Me.?

回答1:

In Windows, you can access UI elements only on the UI thread. For that reason, if you need to access them from another thread, you may need to invoke that action on the UI thread.

You need to use the following method to update the text box. This will check if invoking on the main thread is required and if needed, call the same method on the UI thread.

Private Sub UpdateTextBox(ByVal phone_number As String)
    If Me.InvokeRequired Then
        Dim args() As String = {phone_number}
        Me.Invoke(New Action(Of String)(AddressOf UpdateTextBox), args)
        Return
    End IF
    Label_caller.Text = phone_number
End Sub

回答2:

I am probably answering quite late but adding following code in form load event seems solving problem.

Not sure though it's perfect answer or not:

System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = False

来源：https://stackoverflow.com/questions/19858557/vb-net-accessed-from-a-thread-other-than-the-thread-it-was-created-on