An application uses a list box when it requires a list of selectable fields that is too large for the display area or a list of choices that can change dynamically. Each list item contains a text string and a handle. Usually, the text string is displayed in the list-box window; but the handle is available to the application to reference other data associated with each of the items in the list.

A list box always is owned by another window that receives messages from the list box when events occur, such as when a user selects an item from the list box. Typically, the owner is a dialog window (as shown in the following figure,) or the client window of an application frame window. The client- or dialog-window procedure defined by the application responds to messages sent from the list box.

A list box always contains a scroll bar for use when the list box contains more items than can be displayed in the list-box window. The list box responds to mouse clicks in the scroll bar by scrolling the list; otherwise, the scroll bar is disabled.

The maximum number of items permitted in a list box is 32767.