Here is a proper way to do it - inherit a class from native ComboBox and override OnDropDown to raise a custom DropDownOpening event first:
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| Public Class MyComboBox : Inherits ComboBox
Public Event DropDownOpening(sender As Object, e As System.EventArgs)
Protected Overrides Sub OnDropDown(e As System.EventArgs)
RaiseEvent DropDownOpening(Me, e)
MyBase.OnDropDown(e)
End Sub
End Class
Private Sub MyComboBox1_DropDownOpening(sender As Object, e As System.EventArgs) Handles MyComboBox1.DropDownOpening
'reload your list here
'...
End Sub
|
If you anticipate loading to take considerable time, you can wrap your reload code into a construct like this:
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| Dim oldCursor As Cursor = MyComboBox1.Cursor
MyComboBox1.Cursor = Cursors.WaitCursor
'reload your list here
'...
MyComboBox1.Cursor = oldCursor
|
(DoEvents is not needed to propagate cursor change)
