Async call to get status of a radio button

[liborc]

Hello,

I am trying to use the custom sidebar example fetched here in the forum to develop my own indicator, which should take the state of a radio button as input. I have two radio buttons, "Long Position" and "Short position".

They are created in code and load well. In order to get the checked status of these radio buttons, the code of the logic of the indicator however needs to use the dispatcher, which I can't seem to get to work.

I wrote the async call like this (it lives in the OnBarUpdate event of the indicator):

int longShortSwapper = 0; // local variable to hold 1 or -1 for long/short math processing
bool? longOrShort = false; // local variable to hold the status of the radio button for later checks

// check if the current object is already on the calling thread
if (radioLong != null)
{
if (radioLong.Dispatcher.CheckAccess())
{
// execute action directly
longOrShort = radioLong.IsChecked;
}
// otherwise run the action from the thread that created the object
else
{
// dispatch action to calling thread
Dispatcher.InvokeAsync(new Action(() => {
System.Diagnostics.Debugger.Break();
longOrShort = radioLong.IsChecked;
}));
}
}


I am sorry if this is too basic, but I am unable to solve this without help...

Thank you,

Libor

[NinjaTrader_ChelseaB]

Hello liborc,

Are you receiving an error message?

What is the error message?

If you use the Chart's dispatcher (similar to the CustomSidePanelExample) do you still get an error?

http://ninjatrader.com/support/forum/showthread.php?p=499327#post499327

ChartControl.Dispatcher.InvokeAsync((Action)(() =>
{
}));

[liborc]

Hello Chelsea,

I actually used that very same sample code to start my indicator. I added only the code necessary for the creation of the radio buttons (added 2 grid rows and the buttons).

The controls as well as the rest of the code load with no error, but the OnBarUpdate event code I wrote just does not get the value of the radioLong radio button.

My full OnBarUpdate code is very short:

/// The radio button status code lives here
protected override void OnBarUpdate()


{

bool? longOrShort = false; // local variable to hold the status of the radio button for later checks

// check if the current object is already on the calling thread
if (radioLong != null)
{
if (ChartControl.Dispatcher.CheckAccess())
{
// execute action directly
longOrShort = radioLong.IsChecked;
}
// otherwise run the action from the thread that created the object
else
{
// dispatch action to calling thread
ChartControl.Dispatcher.InvokeAsync(new Action(() => {
System.Diagnostics.Debugger.Break();
longOrShort = radioLong.IsChecked;
}));
}
}

Print("longOrShort: " + longOrShort.ToString());

}


It just does not pick up the value of radioLong at all.

I am attaching the rest of the code, in case you have the time to have a look at it. I highlighted all my changes to your original code so it should be easy to read.

Many thanks again for all your help, here and in other threads.

Libor

[NinjaTrader_ChelseaB]

Hello liborc,

As soon as I commented out the 'System.Diagnostics.Debugger.Break();' line which does not work in NinjaTrader, and then moved the print to action block of the dispatch so the print is printed after the bool is set, it worked without issue.

Are you expecting the print outside of the dispatch call to be called after the dispatch call? (It won't, these are actions happening on two different threads)

[liborc]

Hi Chelsea,

thank you so much. The help here, from you and everyone else, is just outstanding. It is a great customer service - most competent and efficient.

(just to explain: I debug in Visual Studio and there, the Debugger.Break statement is necessary as there is otherwise no way I know of to set up breakpoints to debug the async calls. Also, I used a private variable instead of local to store the result of the property read and it works as expected now.)

Best,

Libor

[NinjaTrader_ChelseaB]

Hi Libor,

Below is a link to a video showing how to use break points in VS.

https://www.screencast.com/t/KmiCO6ufge0t