I think you are trying to mix C# and VB.Net. In VB you access application settings using
My.Settings
, and the form closing event is declared like this]
Private Sub Form1_FormClosing(sender As System.Object, e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
End Sub
You also don't say how your user is creating new items to enter into the combo box, and what method is used to save these temporarily, before closing the form.