By default, the ShowClearButton property is 0 (that indicates that the clear-button is hidden). The ShowClearButton property shows or hides the control's clear-button. The clear button clears the control's label and selection. The clear-button is displayed next to drop down button, and can be hidden, always visible or visible only if there is a selection or get the focus. The Background(exClearButtonUp) property specifies the visual appearance for the clear button, when it is up, while the Background(exClearButtonDown) property specifies the visual appearance for the clear button, when it is down. The DropDownButtonWidth property retrieves or sets the width, in pixels, to display the drop down button of the control (including the clear-button).

(the x indicates the clear-button)

The ShowClearButton property supports the following values: 

• -1, the clear-button is always shown
• 0, the clear-button is not visible
• 1, the clear-button is visible only if the control's label is not empty or there are selected-items
• 2, the clear-button is visible only if the control has the focus
• 3 (1 OR 2), the clear-button is visible only if the control's label is not empty or there are selected-items (1) and the control has the focus (2)

For instance, the ShowClearButton property on 3 (1 OR 2) specifies that the clear-button is shown only if required (the control's label is not empty) and the control has the focus.