Why doesn't this event fire?

Add a form. Add a tabcontrol to the form. Add some tabs to the tabcontrol. Add the following code to the form.

Why doesn't the TabControl1.SelectedIndexChanged event fire when I *set* the selectedIndex How do I make it so that the event *does* fire if the value is set through code

Public Class Form1
    Inherits System.Windows.Forms.Form

' Windows forms designer code removed

    Private _iLastIndex As Short

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        SelectTab(TabControl1, 0)
    End Sub

    Private Sub SelectTab(ByVal ctrl As TabControl, ByVal iTab As Short)
        ctrl.selectedIndex = iTab
    End Sub

    Private Sub TabControl1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TabControl1.SelectedIndexChanged
        Try
            If _iLastIndex <> TabControl1.SelectedIndex Then
                MsgBox(TabControl1.SelectedTab.Name)
                _iLastIndex = TabControl1.SelectedIndex
            End If
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub

End Class

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Why doesn't this event fire?

Aaron Marten - MSFT
Setting _iLastIndex = -1 initially will cause your code to fire. You'll just get the error message the first time before the form is drawn. Setting TabControl1.SelectedIndex = -1 will give the same result.

The event fires everytime, it's just that after the form is drawn the first tabpage (page 0) is set as selected.
Doom Gaze
Weel, it doesn't fire for me. So I'll scrap that method and look for another solution.
Ciprian Gerea MSFT
It does.

_iLastIndex is initialized to 0, meaning "_iLastIndex <> TabControl1.SelectedIndex" returns false.

Try calling SelectTab(TabControl1, 1) and you'll see that the event does fire.
Bo Yu
I've tried setting _iLastIndex to -1 beforehand - it still doesn't go through.

how do I make it fire <u>on form load</u> for tab index "0"
Why doesn't this event fire?

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