The System.Web.UI.WebControls.Repeater control uses the Repeater.RequiresDataBinding property to determine whether the control needs to call the Repeater.DataBind method to bind to its specified data source.

Each time the set accessor is called on either the Repeater.DataSource, Repeater.DataSourceID, or Repeater.DataMember property to change the data source after the Repeater.OnInit(EventArgs) method has already been called, ASP.NET sets the value of the Repeater.RequiresDataBinding property to true. The value of the Repeater.RequiresDataBinding property is also set to true when the Repeater.OnDataSourceViewChanged(object, EventArgs) method is called.

ASP.NET sets the value of the Repeater.RequiresDataBinding property to false immediately after the Repeater.DataBind method is called.