Question

I have created a simple class to filter out data from a data stream. The problem is that if I use more than one ValueFilter object, they all use the same queue. I want there to be a separate queue for each ValueFilter Object. I am declaring the ValueFilter in my main program like this: ValueFilter filter = new ValueFilter(); Should I be using some kind of constructor?

using System;
using Microsoft.SPOT;
using System.Collections;
namespace foo
{
    class ValueFilter
    {
        private const int FILTER_QUEUE_SIZE = 10;
        private static int sum = 0;
        private static Queue queue = new Queue();

        public int FilterValue(int value)
        {
            if (queue.Count >= FILTER_QUEUE_SIZE)
            {

                if (System.Math.Abs((int)(value - sum/queue.Count)) < 3000)
                {
                    queue.Enqueue(value);
                    sum += (int)(value - (int)queue.Dequeue());                  
                }
            }
            else
            {
                queue.Enqueue(value);
                sum += (int)value;
            }

            return sum / queue.Count;
        }
}

Answer 1

Since the Queue seems to be private, all you need to do is remove the static modifier:

//private static int sum = 0;
//private static Queue queue = new Queue();
private int sum = 0;
private Queue queue = new Queue();

Now every ValueFilter instance has its own sum and queue instances. A non-static member is an instance member.