This function sets a default Wait Page URL which overrides the hardcoded one and the one specified in web.config. The wait page for a particular ITaskWaiter is determined in the following order: 1) The URL returned by ITaskWaiter.GetWaitPageURL 2) If this is null, then the WaitPage URL registered with the WaitPageHelper (using the RegisterDefaultWaitPageURL function) 3) If no URL has been registered with the above function, it comes from the AppSetting “DefaultWaitPageURL” in the web.config file. 4) If this AppSetting is not set, a hardcoded WaitPage URL of "~/WaitPage.aspx" is used.
This function is used just after the originating page starts the task. It registers the corresponding ITaskWaiter object with the WaitPage framework. It returns true if the task was registered, and false if the taskWaiter couldn’t be registered, if, for example, another task already exists.