The BaseDataList control uses the RequiresDataBinding property to determine whether the control needs to call the DataBind method to bind to its specified data source.
Each time the set accessor is called on either the DataSource, the DataSourceID, or the DataMember property to change the data source after the OnInit method has already been called, ASP.NET automatically sets the value of the RequiresDataBinding property to true. The value of the RequiresDataBinding property is also set to true when the OnDataSourceChanged method is called.
ASP.NET automatically sets the value of the RequiresDataBinding property to false immediately after the DataBind method has been called.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)