1. Create a new console application in Visual Studio.

2. Next, add a class called Demo to your console application.

3. Inside the Demo class, add a method called DoBackgroundTask() with the public void modifiers, and add the following console output to it:

        public void DoBackgroundTask()
        {
          WriteLine($"Thread {Thread.CurrentThread.ManagedThreadId} has
          a threadstate of {Thread.CurrentThread.ThreadState} with
          {Thread.CurrentThread.Priority} priority");
          WriteLine($"Start thread sleep at {DateTime.Now.Second}
                    seconds");
          Thread.Sleep(3000);
          WriteLine($"End thread sleep at {DateTime.Now.Second} seconds");
        }

4. In the void Main method of your console application, create a new instance of your Demo class and add it to a new thread called backgroundThread. Define this newly created thread to be a background thread and then start it. Finally, set the thread to sleep for 5 seconds. We need to do this because we created a background thread that is set to sleep for 3 seconds. Background threads do not prohibit foreground threads from terminating. Therefore, if the main application thread (which is by default a foreground thread) terminates before the background thread completes, the application will terminate and also terminate the background thread:

        static void Main(string[] args)
        {
          Demo oRecipe = new Demo();
          var backgroundThread = new Thread(oRecipe.DoBackgroundTask);
          backgroundThread.IsBackground = true;
          backgroundThread.Start();
          Thread.Sleep(5000);
        }

5. Run your console application by pressing F5. You will see that we have created a background thread with a normal priority:

6. Let's modify our thread and set its priority down to low. Add this line of code to your console application:

        backgroundThread.Priority = ThreadPriority.Lowest;

This line will downgrade the thread priority:

        Demo oRecipe = new Demo();
        var backgroundThread = new Thread(oRecipe.DoBackgroundTask);
        backgroundThread.IsBackground = true;
        backgroundThread.Priority = ThreadPriority.Lowest;
        backgroundThread.Start();
        Thread.Sleep(5000);

7. Run your console application again. This time, you will see that the thread priority has been set to the lowest priority:

8. Go back to your DoBackgroundTask() method and add Thread.CurrentThread.Abort(); right before Thread.Sleep(3000); is called. This line will prematurely kill the background thread. Your code should look like this:

        public void DoBackgroundTask()
        {
          WriteLine($"Thread {Thread.CurrentThread.ManagedThreadId} has a
          threadstate of {Thread.CurrentThread.ThreadState} with
          {Thread.CurrentThread.Priority} priority");   
          WriteLine($"Start thread sleep at {DateTime.Now.Second} 
                    seconds");
          Thread.CurrentThread.Abort();
          Thread.Sleep(3000);
          WriteLine($"End thread sleep at {DateTime.Now.Second} seconds");
        }

9. When you run your console application, you will see that the thread is aborted before the Thread.Sleep method is called. Aborting a thread in this way, however is, generally, not recommended: