calling 'OnStateChange' method. Object reference not set to an instance of an object

[ballboy11]

I have an indicator that works with no issues but on the log and trace I get the error
Error on calling 'OnStateChange' method. Object reference not set to an instance of an object

This error is too vague but I Know it is in OnStateChange. I tried to debug it in Visual studio 2017 but I can not get the breakpoints activated to find where the issue is.

When adding breakpoints The error I get is breakpoints will not be hit. No symbols have been loaded for this document.
Does anyone know how to fix this in order to use the breakpoints?

[ballboy11]

well I found the issue but I was wondering if there is a better way than just a regular try and catch

try
{
ChartControl.MouseLeftButtonDown -= MouseClicked;
}
catch { }

[ballboy11]

Lastly if you want to use visual studio 2017 you have to compile in ninjatrader in order for the breakpoints to be recognized

[NinjaTrader_Jesse]

Hello ballboy11,

Thank you for the post.

The error you are getting is a general C# error relating to using an object that is null. You can search online (google) for this error message ( Object reference not set to an instance of an object) to gather further details about it. OnStateChange is simply the location, however, there are multiple states so adding a Print(State) at the beginning of OnStateChange can help debug this type of situation.

You have likely used ChartControl either in a state where it cannot be used, or the script is being used in a use case where ChartControl is not present. The solution is to just check if the object is null. I would never suggest using try/catch for general purpose cases like this I would only suggest using try/catch for targeted debugging when you know what exception should be raised.

if(ChartControl != null)
{
   //do the logic here
}

In regard to visual studio, that would be correct, visual studio would require you to compile NinjaTrader in debug mode for breakpoints to be met. We have a guide on debugging with visual studio here: https://ninjatrader.com/support/help...=visual+studio

Please let me know if I may be of additional assistance.