“ProcessStateChangedQueue”的重载不匹配委托“System.EventHandler”

Question

我正在尝试设置一个计时器，出于某种原因，当我尝试递归调用ProcessStateChangedQueue()时，我不断收到错误。我最初尝试使用Timer而不是DispacherTimer，但这是一个WPF应用程序。如果我使用计时器，我本可以完成timer.elapsed，但在这种情况下不能。好像我必须使用timer.tick。我以前从未用过这个。您可以看到timer.elapsed被注释掉的地方，我只需要将其修复到我可以递归调用ProcessStateChangedQueue()的位置，如下所示。唯一的错误是No overload for "ProcessStateChangedQueue" matches delegate "System.EventHandler"也许我不应该使用EventHandler。我只是不确定......有什么想法吗？

#region ********** STATE **********

public delegate void MapStateChangedHandler(object sender, MapStateEventArgs e);
public event MapStateChangedHandler MapStateChanged;
private Queue<String> stateChangedQueue = new Queue<String>();
private bool processingStateChanged = false;

private void RaiseMapStateChanged(string property)
{
    if (!CanSaveState) return;
    RebuildState();
    if (MapStateChanged != null)
    {
        //MapStateChanged(this, new MapStateEventArgs(property, State));
        stateChangedQueue.Enqueue(property);
        if (!processingStateChanged)
        {
            ProcessStateChangedQueue();
        }
    }
}

private void ProcessStateChangedQueue()
{
    if (stateChangedQueue.Count != 0)
    {
        processingStateChanged = true;
        MapStateChanged(this, new MapStateEventArgs(stateChangedQueue.Dequeue(), State));
        DispatcherTimer timer = new DispatcherTimer();
        timer.Interval = TimeSpan.FromMilliseconds(500);
        //timer.Elapsed = timer.Elapsed + new ElapsedEventHandler(ProcessStateChangedQueue);
        timer.Tick += new EventHandler(ProcessStateChangedQueue);
        timer.Start();
    }
    else
    {
        processingStateChanged = false;
    }
}

private void RebuildState()
{
    State.IsMonochrome = Monochrome;
    State.SelectedMapIndex = MapTileLayers.IndexOf(SelectedBaseMap);
    Dictionary<int, double> overlays = new Dictionary<int, double>();
    foreach (MapOverlay overlay in MapOverlays)
    {
        if (overlay.IsVisible)
            overlays.Add(MapOverlays.IndexOf(overlay), overlay.Opacity);
    }
    State.MapOverlays = overlays;
    State.ContrastValue = Contrast;
}