using var iDisposable = Observable.FromEventPattern(ed, nameof(ed.PointMonitor))  
    .Select(x => (PointMonitorEventArgs)x.EventArgs)  
    .Subscribe(args =>  
    {  
        // var pt = args.Context.ComputedPoint;  
    }

    private static IDisposable? documentManagerSubscribe;

    public static void Init()
    {
        documentManagerSubscribe = Observable
            .FromEventPattern(Application.DocumentManager, nameof(Application.DocumentManager.DocumentActivated))
            .Select(x => x.EventArgs)
            .OfType<DocumentCollectionEventArgs>()
            .Select(x => x.Document)
            .Subscribe(DocumentActivatedHandler);

        DocumentActivatedHandler(Application.DocumentManager.MdiActiveDocument);
    }

    private static readonly SerialDisposable _serialDisposable = new();
    
    private static void DocumentActivatedHandler(Document? doc)
    {
        if(doc is null)
            return;
        _serialDisposable.Disposable = Observable.FromEventPattern(doc,nameof(doc.CommandWillStart))
            .Select(x=>(CommandEventArgs)x.EventArgs)
            .Publish()
            .RefCount()
            .Subscribe(x =>
            {
                try
                {
                    var command = x.GlobalCommandName;
                    // do something
                }
                catch (Exception ex)
                {
                    Log.Error("CommandWillStart事件发生错误" + ex.Message);
                }
            });
    }