c# - Is Async/Await using Task.Run starting a new thread asynchronously?

Question

I have read a lot of articles and still cant get understand this part.

Consider this code :

    private async void button1_Click(object sender, EventArgs e)
    {
        await Dosomething();
    }

    private async Task<string> Dosomething()
    {
        await Task.Run((() => "Do Work"));
        return "I am done";
    }

First question:

When I click the button, it will Call DoSomething and await a Task that creates a Thread from the threadpool by calling Task.Run ( if I am not mistaken ) and all of this runs asynchronously. So I achieved creating a thread that does my work but doing it asynchronously? But consider that I don't need any result back, i just want the work to be done without getting any result back, is there really a need to use async/await , and if so, how?

Second question:

When running a thread asynchronously, how does that work? Is it running on the main UI but on a separate thread or is it running on a separate thread and separate is asynchronously inside that method?

Answer 1

1. The purpose of creating Async methods is so you can Await them later. Kind of like "I'm going to put this water on to boil, finish prepping the rest of my soup ingredients, and then come back to the pot and wait for the water to finish boiling so I can make dinner." You start the water boiling, which it does asynchronously while you do other things, but eventually you have to stop and wait for it. If what you want is to "fire-and-forget" then Async and Await are not necessary.

Simplest way to do a fire and forget method in C#?

2. Starting a new task queues that task for execution on a threadpool thread. Threads execute in the context of the process (eg. the executable that runs your application). If this is a web application running under IIS, then that thread is created in the context of the IIS worker process. That thread executes separately from the main execution thread, so it goes off and does its thing regardless of what your main execution thread is doing, and at the same time, your main execution thread moves on with its own work.