Streamwriter not working in strategy (8.0.17.2)

[aog076]

I'm trying to adapt code from samplestreamwriter and it's not working in strategies, once I try to run the strategy is instantly disabled and can not access file. I used system.IO and streamreader before and had no problems at all.

Error message:
Strategy 'Samplestrategy': Error on calling 'OnBarUpdate' method on bar 20: Object reference not set to an instance of an object.

Attached a sample strategy with the streamwriter.
What is missing?

[NinjaTrader_ChelseaB]

Hello aog076,

'Object reference not set to an instance of an object' this error means a variable was used that had a null value without checking that it is not null first.

For exampe;
if (myObject != null)
{
// execute code
}

What is the exact line of code in OnBarUpdate() causing the error?

I notice sw = File.AppendText(path); is in a condition but sw.WriteLine() is not.

If two scripts attempted to open the same file, one would fail and the sw object would be null. Calling .WriteLine() with a null object would cause this error.


I have an example that writes to file you may find helpful.

https://ninjatrader.com/support/forum/forum/ninjatrader-8/strategy-development/100192-comparing-real-time-historical-and-replay-performance#post100192

[aog076]

Hello Chelsea

It might be a bug, if I use the same code in an indicator works fine, it writes on file on every barupdate while running indicator

I copied from sampleStreamWriter indicator that was posted by NT team

But when I try to use in a strategy but gives an error

Attached sampleindicator, you can see that it works

[NinjaTrader_ChelseaB]

Hello aog076,

If there is an error, then yes, there is a bug in the script.

I was not able to confirm, which line is the exact line of code causing the error?

Did you test the strategy I have provided you that writes to file? Is this also generating an error?

[aog076]

The example RealtimeReplayHistoricalComparisonsExample works

I'll be working from this script

Thanks for your help

[NinjaTrader_ChelseaB]

Hello aog076,

Do you no longer want to correct the error in your script?

It may be an easy fix..

[aog076]

I just fixed it
It's easy with the example provided

Thanks