Need help with C# list in Strategy

vantojo · (login for full post details)

Hello, C# gurus...

Attached is a strategy that shows a conundrum (for me).

I have a List of Struct....

If the elements of the List Struct are Private I cannot access them inside the strategy..."inaccessible due to its protection level" compiler error. Not sure why.

When the code is as is, it will compile.

BUT when I load multiple instruments in Strategy Analyzer with this strategy, the list acts like it is global...i.e. public.

If you run this strategy against multiple instruments at the same time in Strategy Analyzer, for every 10 bar it will print (for each instance) the List.

As you would see, the list for any instrument shows the data loaded by the last strategy to execute. In other words, it is acting like a public list...

Probably the answer is to have the Struct elements Private...but then it won't compile...

It is the same if I change the Struct to a Class.

There must be some simple nuance I'm missing...can anyone tell me how to fix this?

Many thanks!

rleplae · (login for full post details)

Your problem is due to the fact you create it as a static, static means it has no instantiation
and it's shared across multiple, making different strategies overwrite the same object.

Try this approach :

Code

List<tester> testerList = new List<tester>();	
		
public class tester
		{
			public string		instrumentName {get;set;}
			public int			counter {get;set;}
		};

When adding to the list you create an object

Code

	private void DoFirstTime()
		{
			firstTime = false;
			
			testerList.Clear();
			
			tester tl = new test();
			
			for (int i = 0; i < 10; i++)
			{
				tl.instrumentName = Instrument.FullName;
				tl.counter 		  = i;
				
				testerList.Add(tl);
			}							
			
			PrintList();
		}

vantojo · (login for full post details)

I put this inside the loop

tester tl = new test();

works good...!!

though....

what is the difference between

List<tester> testerList = new List<tester>();

and

private static List<tester> testerList = new List<tester>();

in this case?

rleplae · (login for full post details)

vantojo

I put this inside the loop

tester tl = new test();

works good...!!

though....

what is the difference between

List<tester> testerList = new List<tester>();

and

private static List<tester> testerList = new List<tester>();

in this case?

If you create the list as a static, you are referring to the same memory in all
indicators/strategies that call it.. (google c# static for class, members .. it will
be explained in more detail

Without the static, the new creates a new object, that is different for every
invokation

vantojo · (login for full post details)

what is confusing to me is....

there is one strategy code base

but when multiple instance of the strategy are running...that is one each on multiple Instruments...

then I was expecting each instance of the strategy to be isolated from the other, completely

but this does not appear to be the case

private static List<tester> testerList = new List<tester>();

the "private static", I was expecting to only have the scope of the single instance running, not all instances of the code base

but, no?

rleplae · (login for full post details)

vantojo

what is confusing to me is....

there is one strategy code base

but when multiple instance of the strategy are running...that is one each on multiple Instruments...

then I was expecting each instance of the strategy to be isolated from the other, completely

but this does not appear to be the case

private static List<tester> testerList = new List<tester>();

the "private static", I was expecting to only have the scope of the single instance running, not all instances of the code base

but, no?

Then you don't need static.
Static would be if you want a central place to hold something that you can refer to from, from different places

vantojo · (login for full post details)

so it seems the scope of static is across all running instances of the strategy...

C# is a different model than I'm used to

still, with help of people like you in futures.io, I have been able to implement what I need

many thanks!

Need help with C# list in Strategy

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Need help with C# list in Strategy

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