Add a calculated values to chart

[ashlantz]

I have created an indicator that displays Point Value, ATR and 2 other calculated values on the chart. The point value displays correctly, but the ATR is not calculating correctly (I am comparing it to pre-built ATR Indicator).

The ATR from the code below is not calculating correctly and I am getting an error stating:
Error on calling 'OnBarUpdate' method on bar 15 (Gui.Chart): The calling thread cannot access the object because a different thread owns it.

I would greatly appreciate help in correcting my code to display these values on the chart.

#region Using declarations
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using System.Xml.Serialization;
using NinjaTrader.Cbi;
using NinjaTrader.Gui;
using NinjaTrader.Gui.Chart;
using NinjaTrader.Gui.SuperDom;
using NinjaTrader.Gui.Tools;
using NinjaTrader.Data;
using NinjaTrader.NinjaScript;
using NinjaTrader.Core.FloatingPoint;
using NinjaTrader.NinjaScript.DrawingTools;
#endregion

//This namespace holds Indicators in this folder and is required. Do not change it.
namespace NinjaTrader.NinjaScript.Indicators
{
public class IndicatorLegend : Indicator
{
private double atrValue = 0;
private double riskperlot = 0;
private double stop = 0;

protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
Description = @"Displays PV, Risk/Lot, Stop";
Name = "IndicatorLegend";
IsOverlay = true;
DisplayInDataBox = true;
DrawOnPricePanel = true;
Calculate = Calculate.OnBarClose;
//Disable this property if your indicator requires custom values that cumulate with each new market data event.
//See Help Guide for additional information.
IsSuspendedWhileInactive = true;
}

}
protected override void OnBarUpdate()
{

double currentBid = GetCurrentBid();

//currentBid is using historical data,

if(CurrentBar <= 14) return;

atrValue = ATR(14)[0];
riskperlot = atrValue*Instrument.MasterInstrument.PointValue;
stop = currentBid - atrValue;

Draw.TextFixed(this, "chartlegend", "Point Value = " + Instrument.MasterInstrument.PointValue + Environment.NewLine +
"Risk/lot = " + riskperlot.ToString("F") + "ATR = " + atrValue.ToString("F") + Environment.NewLine +
"STOP = " + stop.ToString("F") + "CurrentBid " + currentBid.ToString("F"),
TextPosition.TopLeft, Brushes.White, new Gui.Tools.SimpleFont("Arial", 12), Brushes.Transparent, Brushes.Transparent, 100);
ChartControl.InvalidateVisual();

//Add your custom indicator logic here.
}


public override string DisplayName
{
get {return "";}
}
}
}

[NinjaTrader_JessicaP]

Hello ashlantz, and thank you for your question. To aid others I am including a formatted version of your code sample.

[FONT=Courier New]#region Using declarations
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using System.Xml.Serialization;
using NinjaTrader.Cbi;
using NinjaTrader.Gui;
using NinjaTrader.Gui.Chart;
using NinjaTrader.Gui.SuperDom;
using NinjaTrader.Gui.Tools;
using NinjaTrader.Data;
using NinjaTrader.NinjaScript;
using NinjaTrader.Core.FloatingPoint;
using NinjaTrader.NinjaScript.DrawingTools;
#endregion

//This namespace holds Indicators in this folder and is required. Do not change it.
namespace NinjaTrader.NinjaScript.Indicators
{
  public class IndicatorLegend : Indicator
  {
    private double atrValue = 0;
    private double riskperlot = 0;
    private double stop = 0;

    protected override void OnStateChange()
    {
      if (State == State.SetDefaults)
      {
        Description = @"Displays PV, Risk/Lot, Stop";
        Name = "IndicatorLegend";
        IsOverlay = true;
        DisplayInDataBox = true;
        DrawOnPricePanel = true;
        Calculate = Calculate.OnBarClose;
        //Disable this property if your indicator requires custom values that cumulate with each new market data event.
        //See Help Guide for additional information.
        IsSuspendedWhileInactive = true;
      }

    }
    protected override void OnBarUpdate()
    {

      double currentBid = GetCurrentBid();

      //currentBid is using historical data,

      if(CurrentBar <= 14) return;

      atrValue = ATR(14)[0];
      riskperlot = atrValue*Instrument.MasterInstrument.PointValue;
      stop = currentBid - atrValue;

      Draw.TextFixed(this, "chartlegend", "Point Value = " + Instrument.MasterInstrument.PointValue + Environment.NewLine +
      "Risk/lot = " + riskperlot.ToString("F") + "ATR = " + atrValue.ToString("F") + Environment.NewLine +
      "STOP = " + stop.ToString("F") + "CurrentBid " + currentBid.ToString("F"),
      TextPosition.TopLeft, Brushes.White, new Gui.Tools.SimpleFont("Arial", 12), Brushes.Transparent, Brushes.Transparent, 100);
      ChartControl.InvalidateVisual();

      //Add your custom indicator logic here.
    }


    public override string DisplayName
    {
      get {return "";}
    }
  }
} [/FONT]

While fully debugging user code is beyond the scope of the support we can provide directly, I did notice a potentially thread-unsafe call to ChartControl.InvalidateVisual . I would like to recommend reviewing this publicly available Microsoft forums help page on the topic.

https://social.msdn.microsoft.com/Forums/vstudio/en-US/bf265395-3088-4001-8656-806d344ad9b7/forcing-refresh-of-a-window-object?forum=wpf

I would also like to recommend that you review the attached code sample for an example which uses a dispatcher to resolve a similar threading behavior. We are happy to answer any specific questions that come up.

[ashlantz]

Hi Jessica - Thank you very much for the reply and the help. I have successfully made the changes you suggested, and on future posts I will insert the code in a more readable format. I am a beginner and appreciate your time and effort in replying.

Regards,
Ashley

[NinjaTrader_JessicaP]

I am glad we were able to help Please don't hesitate to reach out if any other questions come up we could answer