On initial load or after a full post back,- only the ContentPane of the selected tab is rendered.
Note: The states of fields (like TextBox) located on unselected tabs can not persist between postbacks, therefore, if an application needs up-to-date values of those fields, then that option can not be used.
Warning: That property may trigger full post backs and lead to errors, exceptions and other side effects. Therefore, application should test all possible scenarios. If an error happens, then this property should be disabled.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2