Hi,

The problem with that you are doing here is this line of code:

mendel_lowy said:

DirectCast(grid.ActiveCell.EditorComponentResolved,UltraComboEditor).ButtonsRight("myBotton")

This code is trying to drop down the button on the EditorComponentResolved, which in this case is the UltraComboEditor control on the form, not the cell in the grid.The UltraCombo control on the form is not in edit mode - the grid cell is. The grid does not use the control you assign to the EditorComponent property. What happens is that the editor component (the UltraComboEditor) provides a copy of it's internal editor to the grid.

The correct way to do this would be something like this:

    Private Sub UltraGrid1_AfterEnterEditMode(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UltraGrid1.AfterEnterEditMode
        ' Get the grid
        Dim grid As UltraGrid = DirectCast(sender, UltraGrid)

        ' Get the editor from the ActiveCell. Note the use of EditorResolved, not EditorComponentResolved. 
        Dim editor As EmbeddableEditorButtonBase = DirectCast(grid.ActiveCell.EditorResolved, EmbeddableEditorButtonBase)

        ' We could also use EditorWithCombo, if we wanted, but EmbeddableEditorButtonBase is the base
        ' type for all editors that support editor buttons.
        '
        'Dim editor As EditorWithCombo = DirectCast(grid.ActiveCell.EditorResolved, EditorWithCombo)

        ' Get the dropdown button
        Dim dropdownButton As DropDownEditorButton = DirectCast(editor.ButtonsRight("myButton"), DropDownEditorButton)

        ' Drop it down.
        dropdownButton.DropDown()

    End Sub

You will need to add some other checks to this code, like checking for the correct column(s) and checking if the ActiveCell is Nothing, but you this is the basic gist of it.