Threading is not a member of windows... vb.net

At line 22, I am getting two error notes:  

Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Input, DirectCast(Sub() element.Focus(),

Dispatcher: Dispacher is not declared. It may be inaccessible due to its protection level.
System.Windows.Threading: Threading is not a member of windows

Question: How can I fix this?

Please, in addition to description of the direction, give me the syntax for my use.


tabcontrol.IsSelected=true;
PutFocusOnControl(textBox1);
and define the method...

 private void PutFocusOnControl(Control element)
        {
            if (element != null)
                Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Input,
                    (System.Threading.ThreadStart)delegate
                    {
                        element.Focus();
                    });
        }

or:

                TabControl1.SelectedTab = tabChannels
                PutFocusOnControl(txtChannels_channel)

    Private Sub PutFocusOnControl(element As Control)
        If element IsNot Nothing Then
            Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Input, DirectCast(Sub() element.Focus(), System.Threading.ThreadStart))
        End If
    End Sub

from:
http://stackoverflow.com/questions/3865370/unable-to-set-focus-on-controls-inside-tab-control-in-wpf

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LVL 34
Mike EghtebasDatabase and Application DeveloperAsked:
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it_saigeDeveloperCommented:
Have you added a reference to WindowBase.dll?

http://msdn.microsoft.com/en-us/library/system.windows.threading.dispatcher(v=vs.110).aspx

To add the reference:
1.  Right-click on your project and select 'Add Reference'Capture.JPG2.  Select the .NET tab.Capture.JPG3.  Locate and select 'WindowsBase'Capture.JPG4.  Press 'OK'.

Once you have the reference added then you may need to refer to Dispatcher by it's fully qualified name, e.g. -
System.Windows.Threading.Dispatcher.BeginInvoke(...)

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Or you can add an Imports statement to the top of your code file, e.g. -
Imports System.Windows.Threading

Public Class SomeClass
...
...
End Class

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-saige-
0

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Mike EghtebasDatabase and Application DeveloperAuthor Commented:
Thank you.
0
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