Dispatcher to Thread relationships in WPF

Question

It is not entirely clear to me how many Dispatchers there are in an application and how they are related to, or referenced from Threads.

As I understand it, a WPF ap

Answer 1

A dispatcher is always associated with a thread and a thread can have at most one dispatcher running at the same time. A thread does not need to have a dispatcher.

By default there is only one Dispatcher - For the UI. Sometimes it makes sense to have other dispatchers, other time it does not. A dispatching thread needs to block in the Dispatcher.Run() method in order to process invokes to the dispatcher. A thread such as your console input thread will not be availible to process invokes.