[Browsable(true)]
public ComboBoxStyle DropDownStyle { get; set; }

<Browsable(True)>
Public Property DropDownStyle As ComboBoxStyle

The DropDownStyle property controls the interface that is presented to the user. You can enter a value that provides a simple drop-down list box, where the list always displays, a drop-down list box, where the text portion is not editable and you must select an arrow to view the drop-down, or the default drop-down list box, where the text portion is editable and the user must press the arrow key to view the list.

If you set the DropDownStyle property to DropDownList, you can select only valid values from the list. If you set the DropDownStyle property to DropDown, you can type any value in the editable area of the GrapeCity.Win.Spread.InputMan.CellType.GcComboBox cell. In this case, the Append value of AutoCompleteMode works the same as the SuggestAppend value of AutoCompleteMode.