The ComboBox control combines
TextBox features with a drop-down list—a GUI component that contains a list from which a value can be selected. A
ComboBox usually appears as a
TextBox with a down arrow to its right. By default, the user can enter text into the
Text-Box or click the down arrow to display a list of predefined items. If a user chooses an element from this list, that element is displayed in the
TextBox. If the list contains more elements than can be displayed in the drop-down list, a scrollbar appears. The maximum number of items that a drop-down list can display at one time is set by property MaxDropDownItems. Figure 15.21 shows a sample
ComboBox in three different states.