How to assign values to struct array by calling a function whose return type is struct.

Question

I have created windows application, and i use C# code. in this , call a readdbdata method whose return type is structure. and i want to assign this returned value to the structure array.

{

acccode = 120101000001; widget = 1;
            result = ebis.ReadData(conn, acccode);
            for (int i = 0; i < result.Count; i++)
            {
                UserProfile details = (UserProfile)result[i];               
                details.metric[i] = ebis.ReadDBData(conn, details.usercode, "120101000001");//here an error is showing "An unhandled exception of type 'System.NullReferenceException' occurred in eBis Application.exe
"

            }
}

//this are the code in main application. the following code is ReadDBData

 public Metric ReadDBData(MySqlConnection connection, string usercode, string accode)
        {

            int count = 0;
            ArrayList userDataList = new ArrayList();
            Metric[] usermetric;

            command = new MySqlCommand("SELECT SUM(d.amt) Amount, MAX(d.CREATED_DATE) createddate, MAX(d.MODIFIED_DATE) modifieddate FROM ddata d, branchuser b, userprofile p WHERE d.acccode = '" + accode + "' AND d.br = b.BRCODE  AND b.USERCODE = p.CODE AND cancel = 'No' and b.USERCODE='" + usercode + "' GROUP BY b.USERCODE;", connection);
            adapter = new MySqlDataAdapter(command);
            adapter.Fill(dt);
            int i;
            count = dt.Rows.Count;
            usermetric = new eBisExtension.Metric[count];
            for (i = 0; i < dt.Rows.Count; i++)
            {
                usermetric[i] = new Metric
                {
                    code = accode,
                    amount = Convert.ToDouble(dt.Rows[i]["Amount"].ToString()),
                    amountstring = Convert.ToString("{\"value\":" + dt.Rows[i]["Amount"].ToString() + "}")
                };
                return usermetric[i];
            }

        }

structures in my class

public struct Metric
    {
        public string code;
        public double amount;
        public string amountstring;
    };

public struct UserProfile
    {
        public string usercode;
        public string name;
        public string group;
        public string password;
        public string email;
        public Metric[] metric;
    };

Plz help me..i wanted to complete this project as early as possible.

Answer 1

An unhandled exception of type 'System.NullReferenceException' occurred in eBis Application.exe means you are trying to access variable that does not have something assigned to it.

I would put a break point on the line of code giving you an error and make sure details is not null. If it is not I would step into your ReadDBData function and see where you get the error. Maybe you are not returning any records from the query