Is DispatcherTimer preferred in NT8?

[GaryAlbers]

Is DispatcherTimer preferred in NT 8?
If not, what is?
If it is, Can anybody point out why this code is not resulting in my timer method being called?

dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
dispatcherTimer.Tick += timer_Tick;
dispatcherTimer.Interval = new TimeSpan(0,0,1);
dispatcherTimer.Start();

See attachment for runnable sample strategy code with print statements to show not working.

Thanks,
Gary

[GaryAlbers]

Here is attachment

Attachment shows timer never starts.

[sledge]

Attachment shows timer never starts.

It's working here so well, it didn't stop!!! I paused Playback-MR and it didn't stop.
I even disabled the strategy, and it keeps on plugging away like the Energize Bunny!!!!

Enabling NinjaScript strategy 'GTestTimer/70428016' : On starting a real-time strategy - StartBehavior=WaitUntilFlat EntryHandling=All entries EntriesPerDirection=1 StopTargetHandling=Per entry execution ErrorHandling=Stop strategy, cancel orders, close positions ExitOnSessionClose=True / triggering 30 seconds before close SetOrderQuantityBy=Strategy ConnectionLossHandling=Recalculate DisconnectDelaySeconds=10 CancelEntriesOnStrategyDisable=False CancelExitsOnStrategyDisable=False Calculate=On bar close IsUnmanaged=False MaxRestarts=4 in 5 minutes
Timer created and started
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
Disabling NinjaScript strategy 'GTestTimer/70428016'
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick
----- timer_Tick

[sledge]

Is DispatcherTimer preferred in NT 8?
If not, what is?

I used this in NT7 and it is in the NT8 documentation, along with System.Timers.Timer.

There should be examples floating around here.

*I have not tried in NT8.

http://ninjatrader.com/support/helpGuides/nt8/en-us/?triggercustomevent.htm

[GaryAlbers]

Oops

Sorry sledge,

I forgot to add the Termination state in the sample.

When I retried my own example on a new chart (and with a fresh nights sleep) it is working for me too.

Sorry for the false alarm.

Gary

[GaryAlbers]

Getting weird

I can only get it to run when the timer is created in the Configure state.
But that seems wrong because configure state is called again when strategy dialog is opened in order to stop the strategy (this surprised me).

When I start the timer in historical or realtime state, I don't see the Tick event fire.
I attached an updated example.

Any ideas on why the timer would not fire>

Gary

[sledge]

I can only get it to run when the timer is created in the Configure state.
But that seems wrong because configure state is called again when strategy dialog is opened in order to stop the strategy (this surprised me).

When I start the timer in historical or realtime state, I don't see the Tick event fire.
I attached an updated example.

Any ideas on why the timer would not fire>

Gary

I could NOT get it to fire when turning on Enabled in the Configure screen. No idea why. Probably NT8B10 bug of some sorts.

It would only enable/run when I enabled it in the Strategies tab screen.

http://screencast.com/t/z4uh0hZhTPu

[GaryAlbers]

Interesting distinction to discover sledge. It does sound like a bug.

I also discovered that by using System.Timers.Timer instead of System.Windows.Threading.DispatcherTimer it works as expected.

[NinjaTrader_JessicaP]

Hello sledge and GaryAlbers,

I will be testing this code momentarily. First, though, I did notice several changes in the code you provided GaryAlbers that were not directly related to either Timer or DispatcherTimer. I am going to provide a summary of the differences. Lines starting with a - are in the first sample, lines starting with a + are in the second sample, and all other lines are in both samples. I will use ... to mean that I am skipping lines of code.

[FONT=Courier New]
...

             {
                 ClearOutputWindow();
             }
-            else if (State == State.Realtime)
+            else if (State == State.Historical)
             {
                 dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
                 dispatcherTimer.Tick += timer_Tick;

...

                 dispatcherTimer.Start();
 Print("Timer created and started");
             }
+            else if (State == State.Realtime)
+            {
+            }
+            else if (State == State.Terminated)
+            {
+                disableTimer();
+            }
         }
 
         private void disableTimer()

...
 
         private void timer_Tick(object sender, EventArgs e)
         {
-            Print("----- timer_Tick");
+            TriggerCustomEvent(o =>
+            {
+                Print("----- timer_Tick");
+            }, this);
+
         }
[/FONT]

For the purpose of clean testing, I will make the following choices :

[FONT=Courier New]
...

             {
                 ClearOutputWindow();
             }
             [B]else if (State == State.Realtime)[/B]
             {
                 dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
                 dispatcherTimer.Tick += timer_Tick;

...

                 dispatcherTimer.Start();
 Print("Timer created and started");
             }[/FONT]
[FONT=Courier New][FONT=Courier New]             else if (State == State.Terminated)
             {
                 disableTimer();
             }[/FONT]
         }
 
         private void disableTimer()

...
 
         private void timer_Tick(object sender, EventArgs e)
         {
             Print("----- timer_Tick");
         }[/FONT]

I will test in each of the states you mentioned where I have bolded above.

I will reply again when I have determined whether DispatcherTimer is working properly.

[NinjaTrader_JessicaP]

Hello,

I was able to confirm, using the attached C# file, that System.Windows.Threading.DispatcherTimer will only fire from State.Configure. Thank you for your report. The QA team has been made aware of this issue. I will update this thread when there is more information available.

[NinjaTrader_JessicaP]

I have some feedback as to why the Dispatcher timer will not load in this context. I am providing a quote from the publicly available link to Microsoft's documentation for the DispatcherTimer class.

If a System.Timers.Timer is used in a WPF application, it is worth noting that the System.Timers.Timer runs on a different thread then the user interface (UI) thread. In order to access objects on the user interface (UI) thread, it is necessary to post the operation onto the Dispatcher of the user interface (UI) thread using Invoke or BeginInvoke. Reasons for using a DispatcherTimer opposed to a System.Timers.Timer are that the DispatcherTimer runs on the same thread as the Dispatcher and a DispatcherPriority can be set on the DispatcherTimer.

In this case, the Dispatcher thread was not made available to user strategies. It is recommended that you use System.Timers.Timer, which does have support available. I am providing a publicly available link to Microsoft's documentation for System.Timers.Timer class :

https://msdn.microsoft.com/en-us/library/system.timers.timer.aspx

[GaryAlbers]

Thank you for the follow up and documentation!