意外的java.lang.IllegalArgumentException：Xamarin中ArrayMap中的重复键

Question

我在C＃Xamarin代码中得到了这个神秘异常：

// startTime contains DateTime.Now set earlier in code
//_progressNotification and _..Manager were set once earlier and are never null
//The various Duration variables are doubles with values  >=0 (totalDuration is never zero) 
// The following code is inside var progressHandler = new Progress<double>(p =>
    var progress = (int)Math.Round((p*video.Duration.TotalSeconds + downloadedDuration) * (100d/totalDuration));
    progress = Math.Min(progress, 100);
    progress = Math.Max(progress, 0);
    var secondsPasssed = (DateTime.Now - startTime).TotalSeconds; // For how many seconds are we downloading
    var remainingTine = (downloadedDuration + p * video.Duration.TotalSeconds) <= 0 ? "??:??:??" : TimeSpan.FromSeconds((secondsPasssed * totalDuration / (p * video.Duration.TotalSeconds + downloadedDuration)) - secondsPasssed).ToString(@"hh\:mm\:ss");
    _progressNotification.SetContentText($"{i}/{totalItemsInQueue} {remainingTine}");
    _progressNotification.SetProgress(100, progress, false);
    _notificationManager.Notify(ProgressNotificationId, _progressNotification.Build()); // This line throws the exception

基本上，进度方法在0到1（p）之间执行，然后进行一些简单的数学运算来计算进度值，然后发布（更新）显示此进度的通知

它在大多数情况下都能很好地工作，但有时会抛出上面提到的神秘异常。

我无法弄清楚导致异常发生的原因。