Variable depending on Tab focus - vb.net

Question

i have question that is bugging me for quite some time but im unable to get this around my mind.
So i have a program that contains 8 tabs, all using same formula for calculating when i click's the button on this page but base value is depending on whitch tab is selected and which button is clicked
variables a1 and a2 are the same values accessing exacly the same database just like b1&b2 and c1&c2 working as comboboxes
Private Sub Calculate() Handles button1.Click
value1 = 0.5
sum1 = a1.selectedValue*b1.SelectedValue*c1.SelectedValue*value1
textbox1.value = sum1.value
Private Sub Calculate2() Handles button2.Click
value2 = 0.55
sum2 = a1.selectedValue*b2.selectedValue*c2.selectedValue*value2
texbox2.value = sum2.value
is there any way to make value by depending on the tab that's focused and simplify it? like
Private Sub Calculate(sender As Object, e As EventArgs) Handles button1.Click, button2.Click, button3.Click
if tabpage1 is focus then
value = 0.05
elseif tabpage2 is focus then
value = 0.55
end if
if a1 is selected then
a=a1.value
elseif a2.is selected then
a=a2.value
......
endif
.......
sum = a*b*c*value
if tabpage1 is focus then
textbox1.value = sum.value
else
....
endif
??
i know code above is far from "simple" and actually the handling buttons in each sub is maybe hmmm... better? Just looking at other perspectives to do this 8 tabs in just one sub

Answer 1

I'd suggest that the best solution is something like this:
Dim selectedTab = TabControl1.SelectedTab
Dim tb = selectedTab.Controls.OfType(Of TextBox)().First()
Dim value = CInt(selectedTab.Tag)
'Use tb and value here.
You just need to set the Tag property of each TabPage to the appropriate value and you may need to adjust that second line if there are other TextBoxes on each page or it's inside another container. There's obviously multiple ComboBoxes on each page so that part might look like this:
Dim cbs = selectedTab.Controls.OfType(Of ComboBox)().ToArray()
Dim cbb = cbs(0)
Dim cbc = cbs(1)

Answer 2

you can use method Focused or ActiveControl or SelectedTab/Index as :
Private Sub Calculate(sender As Object, e As EventArgs) Handles button1.Click, button2.Click, button3.Click
If sender Is button1 Then '' Button1 is clicked
If TabControl1.SelectedTab Is tabpage1 Then
'' If tabpage1.Focused OrElse Me.ActiveControl Is tabpage1 Then '' Tabpage1 if focused Or Tabpage1 is Active Control
'' Your Code
End If
End If
If sender Is button2 Then '' Button2 is clicked
If TabControl1.SelectedTab Is tabpage2 Then
'' If tabpage2.Focused OrElse Me.ActiveControl Is tabpage2 Then '' Tabpage2 if focused or Tabpage2 is Active Control
'' Your Code
End If
End If
End Sub