Use DropDownRows to indicate the maximum height of the drop-down list that appears when the user clicks the drop-down button on values that have a pick list. DropDownRows is an upper limit: if the pick list has fewer entries that DropDownRows, the drop-down list includes only a line for every item in the list. 

DropDownRows is ignored for values that do not have a pick list. To provide a value in the value list editor with a drop-down button and pick list, you do either of the following: 

For the appropriate entry in the ItemProps property, set the EditStyle property to esPickList and set the PickList property to the list of items. 

Write an OnGetPickList event handler that supplies the items in the list. 

OnGetPickList 

Values 

ItemProps