How does dispatcher.invoke work

Antti K. Antti Koskela is a proud digital native nomadic millennial full stack developer is that enough funny buzzwords?

That's definitely enough funny buzzwords! He's been a developer from starting with PHP and Java , and he's been working on. This is his personal professional e. We have used Invoke method of Dispatcher. It will not throws any error and successfully update the Content property. BeginInvoke method take a Delegate but it executes the method asynchronously.

That means it immediately returns before calling the method. BeginInvoke returns a DispatcherOperation object. This object can be used for knowing the status of operation whether it is completed or not. It also provides two event Aborted and Completed. Join our newsletter and get an occasional email with a technology and DotNetPattern. Tags wpf C interview reflection mvvm mvvm light interface generics arraylist hashtable using design patterns visitor template flyweight strategy memento mediator command wcf instance management application architecture ajax angularjs forms validations nested forms filters controllers directives bindings expressions ng-app ng-model environment setup threading synchronization entity framework rhino mocks test doubles oops app android linq testing nunit testcase typescript javascript abstract NumPy.

Thread Apartments All objects in the process are grouped into Apartments. Invalid Email. And Dispatcher. InvokeAsync was introduced in this version. So, what are the differences between BeginInvoke and InvokeAsync? There are five overload methods, and it is easy to find that three of them are marked by special attribute to make them invisible in IntelliSense list but you can find them when you use ReSharper.

Are there any differences among these methods? The answer is NO. Here is the code of the method. It probably means Microsoft does not want to maintain this code anymore.

Maybe, a few years later it will be marked as an Obsolete method. This is what the TAP code looks like. What is the feeling when you read these codes? They are almost the same as LegacyBeginInvokeImpl.

So, they added another six methods InvokeAsync , and these all methods above do the same thing. So, in the following paragraphs, we are going to introduce more details about InvokeAsync. Here are the steps of the InvokeAsync method. Therefore, the task and priority we passed will be processed together;. This queue implements a SortedList class, every time it pops a task is depending on its priority.

When the hidden window received that message, it will take a task from the PriorityQueue and execute it. The real situation is more complicated, all details will be shown below. Improve this question. N Vignesh. N 2, 2 2 gold badges 24 24 silver badges 32 32 bronze badges. This is simply affected by the order in which you close the message boxes.

Since the last one is on top, that's the first one you close. Does not have anything to do with DispatcherPriority. I thought so, but am not able to see the other MessageBox es before I close the topmost one. N does my answer explains your query? Add a comment. Active Oldest Votes. Now your code: Three task are queued 1st in background , 2nd in background and 3rd in foreground queue. Hope this explanation clarifies to some extent. Improve this answer. Community Bot 1 1 1 silver badge.

Kylo Ren Kylo Ren 7, 5 5 gold badges 36 36 silver badges 61 61 bronze badges. N I think you didn't read the answer carefully This is because the first MessageBox is blocking the UI thread.

TLS 3, 2 2 gold badges 25 25 silver badges 31 31 bronze badges. Adam Wilson Adam Wilson 1 1 silver badge 11 11 bronze badges. If you were right, I would expect the message boxes to be in the order they have been called.