@stevemorgan答案非常有效. 我基于该代码创建了一个Timer实用程序，以使其更可重用. 我还添加了一个"runOnce"参数，该参数将在第一次滴答之后停止计时器

@stevemorgan answer works really well. I created a Timer utility based on that code to make it more reusable. I also added a "runOnce" parameter that will stop the timer after the first tick

public class PclTimer
{
    public bool IsRunning { get; private set; }

    public TimeSpan Interval { get; set; }
    public Action Tick { get; set; }
    public bool RunOnce { get; set; }
    public Action Stopped { get; set; }
    public Action Started { get; set; }

    public PclTimer(TimeSpan interval, Action tick = null, bool runOnce = false)
    {
        Interval = interval;
        Tick = tick;
        RunOnce = runOnce;
    }

    public PclTimer Start()
    {
        if (!IsRunning)
        {
            IsRunning = true;
            Started?.Invoke();
            var t = RunTimer();
        }

        return this;
    }

    public void Stop()
    {
        IsRunning = false;
        Stopped?.Invoke();
    }

    private async Task RunTimer()
    {
        while (IsRunning)
        {
            await Task.Delay(Interval);

            if (IsRunning)
            {
                Tick?.Invoke();

                if (RunOnce)
                {
                    Stop();
                }
            }
        }
    }
}

我正在MvvmCross中使用它，没有问题:

I´m using this in MvvmCross with no issues:

timer = new Timer(TimeSpan.FromSeconds(4), 
            () => ShowViewModel<UserMatchViewModel>(), true)
            .Start();