.net - Using DispatcherTimer Frequently update to GUI on Windows Phone 8.1 -

I have a problem that is often wp8.1 to update to the GUI. I am in a situation that I will get an update from an async function in an unspecified time, then I have to update the GUI, the Dispatcher timer is good work, but how can I adjust it to my position and how will I know What is the update I completed before closing it? (I do not know at what time I will get the update, it should be like an event holder. I have tried to use the Dispatcher to update the damaged properties, but in any way More often failing in the updated status)? Thanks a lot!

  Private Async Zero Heart Right Measurement Data Chat (Gat Potential Sender, Gatewall Belly Event Argus Args) {Random R = New Random (); Var number = R. Next (0, 300); Lock object (heart reaction) Anu (number); }} Sender Timer. Tick ​​Task = () = & gt; {UpdateGUI (); }; Private Zero UpdateGUI () {lockObject} {int ratio; If (heart-heart Que.TryDequeue (out ratio)) {this.BeatPerMinute.Text = ratio.ToString (); This.heartRateMonitorViewModel.addHeartRatio (Convert.ToUInt16 (ratio)); //outputDataChart.PlotChart (this.heartRateMonitorViewModel.HeartRatio.ToArray ()); } // Return function. FormarSalt ()}} Private observable selection & lt; BeatPerminiteLight chart & gt; HeartRTRO = New Observation Collection & Lieutenant; BeatParaminate Lineschart & gt; () {New BeatPerignine chart (0, 0)}; Public supervision qualification & lt; BeatPerminate LinesChart & gt; Hartartio {Return heart Rieto; // Bind to Line Chart} Set {if (value! = Null & amp; value.Count ()> 0) {heartRatio = value; }}} Personal count = 1; Public Zero AddHeretario (Uhort Beatpermainute) {Heart Options Add (New Beat-onMantine Chart (Count ++, Petminnet);); }