Don't use the code from that post. There are better ways now.
Code:
For Each v As View in Activity.GetAllViewsRecursive
If v Is Label Then
Dim lbl As Label = v
lbl.Text = "Sdf"
End If
Next
This code will handle the following types: Label, EditText, Button, Checkbox, RadioButton and AutoCompleteEditText. They are all subclasses of Label.