C# List + Object reference not set to an instance of an object.
I have this code in C#.
It is returning "Object reference not set to an instance of an object" exception.

Code:
       
        public decimal Calculate(String id)
        {
            decimal Total=0;
            AmountDataDB getData=new AmountDataDB();
            List<AmountData> d = new List<AmountData>();
            d = getData.Amount_Details(id);
            if (d.Capacity != 0)
            {
                foreach (AmountData temp in d)//NullReference exception occurs here
                {
                    Total += temp.Amount;
                }
                
            }
            return Total;
        }

Here, AmountDataDB and AmountData are two classes. Amount_Details returns a list of type AmountData.
C# List + Object reference not set to an instance of an object.
===

I have this code in C#.
It is returning "Object reference not set to an instance of an object" exception.

Code:
       
        public decimal Calculate(String id)
        {
            decimal Total=0;
            AmountDataDB getData=new AmountDataDB();
            List<AmountData> d = new List<AmountData>();
            d = getData.Amount_Details(id);
            if (d.Capacity != 0)
            {
                foreach (AmountData temp in d)//NullReference exception occurs here
                {
                    Total += temp.Amount;
                }
                
            }
            return Total;
        }

Here, AmountDataDB and AmountData are two classes. Amount_Details returns a list of type AmountData.