Member Avatar for markjames2012

Ok i manage to autoselect items on listbox till reach the end of list, but i need it to automatically loop back to the fist selection of indexes when it reach the end list and so on .. i need help on this part newbie here :)

if Me.Listboxs1.SelectedIndex + 1  < Me.ListBox1.items.count then
    Me.ListBox1.SelectedIndex + = 1
End if

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  • Latest Post Latest Post by markjames2012

Dani AI

Generated

is right: his wrap logic will cycle forever if you run it from a timer. If what you really want is a back-and-forth (ping-pong) effect instead of jumping from the last item back to the first, keep a direction flag and flip it at the ends.

' Form-level field
Private movingDown As Boolean = True

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    Dim n = ListBox1.Items.Count
    If n = 0 Then Exit Sub

    If ListBox1.SelectedIndex < 0 Then
        ListBox1.SelectedIndex = 0
        Exit Sub
    End If

    If movingDown AndAlso ListBox1.SelectedIndex >= n - 1 Then movingDown = False
    If Not movingDown AndAlso ListBox1.SelectedIndex <= 0 Then movingDown = True

    ListBox1.SelectedIndex += If(movingDown, 1, -1)
End Sub

If forward-only cycling is fine, a compact alternative to ’s If/Else is to use modulo arithmetic. It also handles the initial state when nothing is selected.

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    Dim n = ListBox1.Items.Count
    If n = 0 Then Exit Sub
    Dim current = Math.Max(ListBox1.SelectedIndex, -1)
    ListBox1.SelectedIndex = (current + 1) Mod n
End Sub

Practical tips:

  • Make sure you are using System.Windows.Forms.Timer in WinForms so the tick runs on the UI thread. If you use System.Timers.Timer or System.Threading.Timer, update the ListBox via Me.Invoke(...) to avoid cross-thread exceptions.
  • Choose a sensible Timer.Interval (e.g., 150–500 ms) so the selection does not race past the user.
  • If this tag truly means ASP.NET, remember server-side SelectedIndex changes will not animate the browser. You would need client-side JavaScript (for example, setInterval) or an ASP.NET AJAX Timer in an UpdatePanel to visually advance the selection. , that distinction often trips people up.

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Member Avatar for Reverend Jim 
If ListBox1.SelectedIndex = ListBox1.Items.Count - 1 Then
    ListBox1.SelectedIndex = 0
Else
    ListBox1.SelectedIndex += 1
End If
Member Avatar for markjames2012

thanks Reverend Jim
Yes your code does select the first index after reach the end list.. but i want something that loops back and fort till i stop the timer
by the way thanks for the reply bro :)

Member Avatar for Reverend Jim

Glad to help.

My code selects the next item in the list and wraps back to the beginning when it reaches the end of the list. If it is in a timer then it will cycle continuously. If there are three items in the list then SelectedIndex will cycle as 0, 1, 2, 0, 1, 2, ...

Member Avatar for markjames2012

thanks again Reverend Jim i tested the code now and its working perfectly

:)

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