I've written a DLL in VB .NET that is called by TradersStudio.  It appears that the object that contains the routines in the DLL is reinstantiated every time a new market is started.  This means that no data can easily be passed on from the analysis of one market to the analysis of another.

First of all, am I right that this is what happens?

Secondly, is there a way to pass such data?  Within TradersStudio Basic, Gvalue1 etc. could be used.  Is there a way to use them here or some other way to retain data?

Thanks.

Yes, you are correct. Each Market is independent. We do this for other reasons when we get to real time.

I will need to check on it, I have not tried it. You can try to use Script.Eval("GValue1="&cstr(myval)) , if that does not work I have other Ideas.

I now have the following code to my DLL:

Public Sub attachScript(ByRef script As Object)

'this is called early on by TradersStudio to pass a pointer to the script object to us.

'It contains the price series etc. Just save the pointer.

test = script.eval("GValue1")

script.Eval("GValue1=" & CStr(test))

End Sub

Test is declared as in Integer earlier.  Test always gets a value of 0 from the first call to script.eval.  Hence, it looks like this method doesn't work.  I would appreciate your other ideas.  (I suppose if all else fails I can save my data in the registry.)

By-the-way, I notice that if I run a sesssion that contains n markets that attachScript and attachMarket are each called alternately n+1 times before the function I explictly call from my indicator is called.  They are each then called once again before my function is called for each new market.  This is not a significant problem for me, but I'm curious as to the reason.

This is the low level function GValueXX is created from try the LangSub and LangFunc API call to use these.

SetBuiltInVar -- Subroutine

Sets the value of a built-in Variable.  Passes the variable number '0' to '254' and the value of the variable as a variant.

There are 255 built-in variables that that can be set using this function. They will remain set for the duration of a backtesting session.  The variable is stored between runs of the 'mom series'.

Return type

A Variant value

Syntax

SetBuiltInVar(Num as Integer,Value as Variant )

Sub Scanner(SLen)

Dim CellRow as Integer

If Close>CloseΗ] amd CloseΏ]  then

CellRow=GetBuiltInVar(0)+1

SetTextValue(GetActiveSymbol(0),CellRow,1,30)

SetTextValue(FormatDateTime(date),CellRow,2,10)

SetTextValue("Uptrend for tomorrows trade ",CellRow,3,40)

SetBuiltInVar(0,CellRow)

End if

End sub

I'm afraid this one is being resistant to solution.  I first tried implement your solution above.  It didn't work.  It looked like the call to GetBuiltInVar didn't via LangFunc didn't return a value.

I then tried a simpler example using the function max3.  Here is the code which is inside a function called from an indicator:

Dim args3(2)

test = 99 'set test to something non-zero so we can see if max3 fills it in.

Dim answer As Integer = m_script.langfunc("max3", args3, test)

If Not m_script.langfunc("max3", args3, test) Then 'get the value of test

     MsgBox("Error calling max3: " & m_script.error, MsgBoxStyle.OkOnly)

End If

Watching this from the debugger, no errors occur. The call to MsgBox does not occur.  Answer is -1 (true) and test keeps its value of 99 instead of being set to max3(5,7,9) = 9.

I tried varients of this code, introducing things that should cause errors.   I changed the dimension for args3 from 2 to 3 and to 1.  I changed "max3" to "max4". I both added and removed an argument to the langfunc routine.  All of the above gave reasonable error messages leading me to believe that I really am calling max3.  The mystery is why I don't get an answer filled into my variable named test.

Can you see what I am doing wrong?  Remember that this is VB .NET (2005) I am using, whose TradersStudio interface is only a beta right now.  Any chance it is the difference between VB 6.0 which has a type of variant and VB .NET which has a type of object instead?

Thanks

I will look into it for you.