NT8 String Conversion

[lee612801]

Hello,

In NT7 I could simply add a string with the following and it provided a default string and allowed me to change it:

public class SMA : Strategy
{
string instrString = "SPY";

---------------------------------------------------------------------------------------------------
#region Properties
[Description("Trade Instrument")]
[GridCategory("Parameters")]
[Gui.Design.DisplayName("Description Here")]
[RefreshProperties(RefreshProperties.All)]
public string InstrString
{
get { return instrString; }
set { instrString = value;}
}

How do I do the same thing in NT8?

Thanks,

Lee

[NinjaTrader_ChelseaB]

Hello Lee,

The attributes have changed from NinjaTrader 7 to NinjaTrader 8.
Please see the help guide to see the available attributes along with examples of how to use them.

http://ninjatrader.com/support/helpGuides/nt8/en-us/attributes.htm

Returning a private variable from a public variable is still possible with NT8 and that same code you have posted with some changes to the attributes would still work. However, in both NT7 or NT8, if the object is serializable already (such as string, int, double) you can choose not to return a private variable.

A simple way to create a public input in NinjaTrader 8 looks like the following:

[NinjaScriptProperty]
[Display(Name="InstrString", Description="Trade Instrument", Order=1, GroupName="NinjaScriptStrategyParameters")]
public string InstrString
{ get; set; }

[lee612801]

Hi Chelsea,

Thank you for the info. The only issue I am having now is I can't get NT8 to use
string InstrString = "SPY"; as a default to populate the strategy properties list like in NT7. I have it added under: protected override void OnStateChange()

It's as if it is completely ignoring the string I added. And when I select the strategy for the chart, it gives me an error saying "Error on getting value for property "InstrString". Object reference not set to an instance of the object". If I select ok on the error window, I can then manually populate the string field and the strategy works fine. So I'm just trying to figure out how to put a default value in for "InstrString" so its not an empty field causing an error

Thanks,

Lee

[NinjaTrader_ChelseaB]

Hello Lee,

I would recommend that you try using the Strategy Builder to create an input to see how this looks in NinjaTrader 8.

Attached is an example exported script that creates a string public input.

[lee612801]

Ok, that was too easy. I just had to remove "string" from "string InstrString = "SPY";".

Thank you for the help.

Regards,

Lee