#961 – A ListBox Has Three Available Selection Modes

By default, a user can select one item at a time in a ListBox.

You can use the SelectionMode property of the ListBox to allow the user to select multiple items.  By default, the SelectionMode property has a value of SelectionMode.Single, allowing the user to select a single item.

You can set SelectionMode to Extended, allowing a user to select multiple items, as follows:

• A mouse left-click selects a single new item, unselecting all previously selected items
• Control + left-click selects/unselects an additional item.  Previously selected items remain selected.
• Shift + left-click selects all items between the most recently selected item and the one being clicked (inclusive).  Previously selected items not in this range are unselected.
• Control + Shift + left-click selects all items within a range without unselecting previously selected items

Setting SelectionMode to Multiple allows selecting multiple items by left-clicking:

• Left-clicking an item selects or unselects the item