When used with a data-virtualized (asynchronous) source, this property will throw an exception; BeginGetSelectedItems and EndGetSelectedItems should be used in this situation.
For a listbox whose SelectionMode is set to Multiple or Extended, this property will return a list that contains the selected items.
For a listbox whose SelectionMode is set to Single, this property will return a list that contains the selected item.
For a single-selection listbox, the selected item can also be retrieved by using the SelectedItem property or the index of the selected item via said property.
.NET: net5.0, net5.0-windows, net6.0, net6.0-macos, net6.0-windows, net7.0, net7.0-macos, net7.0-windows, net8.0, net8.0-browser, net8.0-macos, net8.0-windows, net9.0, net9.0-browser, net9.0-macos, net9.0-windows, net10.0, net10.0-browser, net10.0-macos, net10.0-windows.
.NET Framework: net40, net403, net45, net451, net452, net46, net461, net462, net463, net47, net471, net472, net48, net481.