Dealing with suggestion box
In the combobox control, the DropDown Box can placed in the following two positions:
Using the Suggestion box placement property, you can place the suggestion box at the top or bottom.
SuggestionBox placement at bottom
Displays the suggestion box at the bottom of the combo box control.
combobox.SuggestionBoxPlacement = SuggestionBoxPlacement.Bottom;
SuggestionBox placement at top
Displays the suggestion box at the top of the combo box control.
combobox.SuggestionBoxPlacement = SuggestionBoxPlacement.Top;