Assembly: System.Web (in System.Web.dll)
The method is used primarily by control developers, when deriving a custom control from the ListBox control.
The ASP.NET page framework calls the method on a ListBox control when the LoadPostData method indicates that the state of the list items have changed in the ListBox control. The method calls the OnSelectedIndexChanged method to raise the SelectedIndexChanged event. Control developers can override the OnSelectedIndexChanged method to perform custom processing when the user selects list items in the control.
The method can optionally perform validation before raising the SelectedIndexChanged event for the control. To validate a group of controls on the page when a list item within the ListBox is selected, set the AutoPostBack and CausesValidation properties to true, and then specify the group of controls to validate in the ValidationGroup property.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.