List object trouble

[Riskybiz]

Hi, I've been having some trouble with using a 'List' Object in NinjaScript whilst building the framework for a new project. Can you help sort out what needs to be corrected?

What I'm trying to do is this;

1. Declare a new class 'clsLevel'.
2. On each bar instantiate an instance of clsLevel and populate it with some data.
3. Store each instance of 'clsLevel' into into a list object named 'Levels'.
4. Later refer to the list and the objects stored in it.

So I can get the necessary objects instantiated. However the 'Levels' list is instantiated when OnStartup() is called and then when I try to refer to the object in OnBarUpdate() using

Levels.Add(candLevel)

then the code fails with this message

'Object reference not set to an instance of an object'

and with that I'm stuck. Can you help me out here?

Thanks

Riskybiz

//Design the class

namespace ClassDesign
{
	public class clsLevel
	{
		public bool isInitialised;
		public DateTime startDateTime;
		public DateTime endDateTime;
		public int startBar;
		public int endBar;
		public double highVal;
		public double lowVal;
	
		public clsLevel()
		{
			isInitialised = true;
		}
	}
}


//Instantiate the List object once at the initialization of the indicator

protected override void OnStartUp()
		{
    	// Set any variables or logic you wish to do only once at start of your indicator/strategy
		List<clsLevel> Levels = new List<clsLevel>();
		Levels.Capacity = 10;	
		levelsInitiated = true;
		Print("Levels Initiated: " + levelsInitiated.ToString());
		Print("Capacity " + Levels.Capacity.ToString());
		}
  		
		/// <summary>
        /// Called on each bar update event (incoming tick)
        /// </summary>
        protected override void OnBarUpdate()
        {
            		
			// Use this method for calculating your indicator values. Assign a value to each
            // plot below by replacing 'Close[0]' with your own formula.
            			
			candLevel = new clsLevel();
			
			Print("Candidate Initiated: " + candLevel.isInitialised.ToString());
			
			candLevel.startDateTime = Time[0];
			candLevel.endDateTime = Time[0];
			candLevel.startBar = CurrentBar;
			candLevel.endBar = CurrentBar;
			candLevel.highVal = High[0];
			candLevel.lowVal = Low[0];
			
			Print("StartBar " + candLevel.startBar.ToString());//check to test accessing the object
			
			
			Levels.Add(candLevel);
			
						
			Plot0.Set(High[0]);//just plot something to see that it calculated
			Plot1.Set(Low[0]);//just plot something to see that it calculated
			
				
		}

[koganam]

Hi, I've been having some trouble with using a 'List' Object in NinjaScript whilst building the framework for a new project. Can you help sort out what needs to be corrected?

What I'm trying to do is this;

1. Declare a new class 'clsLevel'.
2. On each bar instantiate an instance of clsLevel and populate it with some data.
3. Store each instance of 'clsLevel' into into a list object named 'Levels'.
4. Later refer to the list and the objects stored in it.

So I can get the necessary objects instantiated. However the 'Levels' list is instantiated when OnStartup() is called and then when I try to refer to the object in OnBarUpdate() using

Levels.Add(candLevel)

then the code fails with this message

'Object reference not set to an instance of an object'

and with that I'm stuck. Can you help me out here?

Thanks

Riskybiz

//Design the class
 
namespace ClassDesign
{
    public class clsLevel
    {
        public bool isInitialised;
        public DateTime startDateTime;
        public DateTime endDateTime;
        public int startBar;
        public int endBar;
        public double highVal;
        public double lowVal;
 
        public clsLevel()
        {
            isInitialised = true;
        }
    }
}
 
 
//Instantiate the List object once at the initialization of the indicator
 
protected override void OnStartUp()
        {
        // Set any variables or logic you wish to do only once at start of your indicator/strategy
        List<clsLevel> Levels = new List<clsLevel>();
        Levels.Capacity = 10;    
        levelsInitiated = true;
        Print("Levels Initiated: " + levelsInitiated.ToString());
        Print("Capacity " + Levels.Capacity.ToString());
        }
 
        /// <summary>
        /// Called on each bar update event (incoming tick)
        /// </summary>
        protected override void OnBarUpdate()
        {
 
            // Use this method for calculating your indicator values. Assign a value to each
            // plot below by replacing 'Close[0]' with your own formula.
 
            candLevel = new clsLevel();
 
            Print("Candidate Initiated: " + candLevel.isInitialised.ToString());
 
            candLevel.startDateTime = Time[0];
            candLevel.endDateTime = Time[0];
            candLevel.startBar = CurrentBar;
            candLevel.endBar = CurrentBar;
            candLevel.highVal = High[0];
            candLevel.lowVal = Low[0];
 
            Print("StartBar " + candLevel.startBar.ToString());//check to test accessing the object
 
 
            Levels.Add(candLevel);
 
 
            Plot0.Set(High[0]);//just plot something to see that it calculated
            Plot1.Set(Low[0]);//just plot something to see that it calculated
 
 
        }

You have a scope problem. Your Levels list should be declared as an indicator Class object, not in the OnStartUp() event.

[Riskybiz]

Thanks, you got it in one. I moved the 'List' instantiation to where the variables are declared in

'public class SupplyDemand : Indicator
{'

and bingo, success.