后台任务正在阻塞 wpf .net 核心应用程序中的主线程

Question

I have a background task in my software which should run indefinitely.

The code repeating the task (and possibly other tasks in the future) looks like this:

public class RunTicketTasks
{
    public async Task RunBackgroundTasks()
    {
        AssignTickets assignTickets = new AssignTickets();
        while (true)
        {
            await assignTickets.AssignTicketCreator();
            await Task.Delay(5 * 60 * 1000);
        }
    }
}

At the same time I have the WPF UI MainWindow.xaml which is the application entry point as far as I know.

within public MainWindow I start the task like the following way:

public MainWindow()
{ 
    InitializeComponent();
    JiraBackgroundTasks.RunTicketTasks ticketTasks = new JiraBackgroundTasks.RunTicketTasks();
    ticketTasks.RunBackgroundTasks();
}

Apparently, this starts the task on the same thread (I believe). The task is started and running successfully, but the UI is beeing blocked due to long running operations. Meanwhile, when I uncomment the last line ticketTasks.RunBackgroundTasks(); the UI just runs fine.

How do I start the task in the background so that my User Interface is still responsive?

EDIT:
The reason I started the task this way was because of exception handling. I can successfully start the task on a different thread as suggested with Task.Run(async () => await ticketTasks.RunBackgroundTasks()); But then I will not receive any exception if something goes wrong.

How can I start the task not blocking the UI and still receive the exception details if an exception is thrown?

The Internet states the following method:

await Task.Run(() => ticketTasks.RunBackgroundTasks());

But this will not work because The await operator can only be used within an async method.

Answer 1

One way to do it is to wrap the task in an async event callback:

public partial class MainWindow : Window
{
    // I mocked your missing types, replace with your own 
    class AssignTickets
    {
        public Task AssignTicketCreator() => Task.CompletedTask;
    }

    public class RunTicketTasks
    {
        public async Task RunBackgroundTasks()
        {
            AssignTickets assignTickets = new AssignTickets();
            int x = 0;
            while (true)
            {
                await assignTickets.AssignTicketCreator();
                await Task.Delay(1000);

                var isRunningOnDispatcher = Application.Current.Dispatcher ==
                    System.Windows.Threading.Dispatcher.FromThread(Thread.CurrentThread);
                Trace.WriteLine($"One second passed, running on dispatcher: {isRunningOnDispatcher}");

                // exception will also get thrown on the main thread
                if (x++ > 3) throw new Exception("Hello!");
            }
        }
    }

    public MainWindow()
    {
        InitializeComponent();

        // event fires on UI thread!
        this.Loaded += async (sender, args) =>
        {
            try
            {
                await new RunTicketTasks().RunBackgroundTasks();
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        };
    }
}