--- title: "ComboBox Control Overview" ms.date: "03/30/2017" f1_keywords: - "ComboBox" helpviewer_keywords: - "drop-down lists [Windows Forms], Windows Forms" - "ComboBox control [Windows Forms], about ComboBox control" - "drop-down lists [Windows Forms], ComboBox control" - "combo boxes [Windows Forms], about combo boxes" ms.assetid: a58b393f-a614-45d1-8961-857a024b5acd --- # ComboBox Control Overview (Windows Forms) The Windows Forms control is used to display data in a drop-down combo box. By default, the control appears in two parts: the top part is a text box that allows the user to type a list item. The second part is a list box that displays a list of items from which the user can select one. For more information on other styles of combo box, see [When to Use a Windows Forms ComboBox Instead of a ListBox](when-to-use-a-windows-forms-combobox-instead-of-a-listbox.md). The property returns an integer value that corresponds to the selected list item. You can programmatically change the selected item by changing the value in code; the corresponding item in the list will appear in the text box portion of the combo box. If no item is selected, the value is -1. If the first item in the list is selected, then the value is 0. The property is similar to , but returns the item itself, usually a string value. The property reflects the number of items in the list, and the value of the property is always one more than the largest possible value because is zero-based. To add or delete items in a control, use the , , or method. Alternatively, you can add items to the list by using the property in the designer. ## See also - - [ListBox Control Overview](listbox-control-overview-windows-forms.md) - [When to Use a Windows Forms ComboBox Instead of a ListBox](when-to-use-a-windows-forms-combobox-instead-of-a-listbox.md) - [How to: Add and Remove Items from a Windows Forms ComboBox, ListBox, or CheckedListBox Control](add-and-remove-items-from-a-wf-combobox.md) - [How to: Sort the Contents of a Windows Forms ComboBox, ListBox, or CheckedListBox Control](sort-the-contents-of-a-wf-combobox-listbox-or-checkedlistbox-control.md) - [How to: Access Specific Items in a Windows Forms ComboBox, ListBox, or CheckedListBox Control](access-specific-items-in-a-wf-combobox-listbox-or-checkedlistbox.md) - [How to: Bind a Windows Forms ComboBox or ListBox Control to Data](how-to-bind-a-windows-forms-combobox-or-listbox-control-to-data.md) - [Windows Forms Controls Used to List Options](windows-forms-controls-used-to-list-options.md) - [How to: Create a Lookup Table for a Windows Forms ComboBox, ListBox, or CheckedListBox Control](create-a-lookup-table-for-a-wf-combobox-listbox.md)