The ToolStripComboBox.DropDownStyle property controls the interface that is presented to the user. You can enter a value that allows for 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. To always display a list that the user cannot edit, use a System.Windows.Forms.ListBox control.