在静态上下文中使用异步更新 UI 不起作用

Question

我正在使用以下代码

public static class Program
{
    [STAThread]
    public static void Main(string[] args)
    {
        CancellationTokenSource tokenSource = new CancellationTokenSource();

        Task timerTask = Program.RunPeriodically(() => { Program.SendNotification($"foo", BalloonIcon.Info); }, TimeSpan.FromSeconds(10), tokenSource.Token);
        timerTask.Wait(tokenSource.Token);
    }

    private static void SendNotification(string message, BalloonIcon balloonIcon)
    {
        new TaskbarIcon().ShowBalloonTip("Title", message, balloonIcon);
    }

    private static async Task RunPeriodically(Action action, TimeSpan interval, CancellationToken token)
    {
        while (true)
        {
            action();
            await Task.Delay(interval, token);
        }
    }
}

我想做的是运行每 10 秒 SendNotification 方法。为此，我调用方法 RunPeriodically.

然而，对 SendNotifcation 的调用抛出一个 InvalidOperationException，说：

The calling thread must be STA, because many UI components require this.

我也试过像这样使用 Dispatcher

private static void SendNotification(string message, BalloonIcon balloonIcon)
{
    Dispatcher.CurrentDispatcher.Invoke(() =>
    {
        new TaskbarIcon().ShowBalloonTip("Title", message, balloonIcon);
    });
}

但它并没有做出改变。

我唯一的猜测是代码不起作用，因为它不是从 Window 实例调用的，而是在没有 this.Dispatcher 的 class 的静态上下文中调用的，但我不知道如何让它在这种情况下工作，非常感谢您的帮助。

Answer 1

下面这个稍微修改过的例子对我来说效果很好。

希望对您有所帮助！

public static class Program
{
    private static NotifyIcon notifyIcon;

    [STAThread]
    public static void Main(string[] args)
    {
        CancellationTokenSource tokenSource = new CancellationTokenSource();

        notifyIcon = new NotifyIcon();
        notifyIcon.Icon = SystemIcons.Information;
        notifyIcon.BalloonTipTitle = "Title";
        notifyIcon.Visible = true;

        Task timerTask = Program.RunPeriodically(() => { Program.SendNotification(DateTime.Now.ToString(), ToolTipIcon.Info); }, TimeSpan.FromSeconds(10), tokenSource.Token);
        timerTask.Wait(tokenSource.Token);
    }

    private static void SendNotification(string message, ToolTipIcon balloonIcon)
    {
        notifyIcon.BalloonTipIcon = balloonIcon;
        notifyIcon.BalloonTipText = message;
        notifyIcon.ShowBalloonTip(500);
    }

    private static async Task RunPeriodically(Action action, TimeSpan interval, CancellationToken token)
    {
        while (true)
        {
            action();
            await Task.Delay(interval, token);
        }
    }
}

在静态上下文中使用异步更新 UI 不起作用

Using async in static context to update the UI is not working

c#

asynchronous

task

sta