Classtaki list veri eklemek

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using System.Web.Script.Serialization;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Jsonyap
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            JavaScriptSerializer js = new JavaScriptSerializer();
            string query = String.Format("SELECT * FROM lecturer ORDER BY id;");
            try
            {
             /*   foreach (DataRow item in SorguCalistir(query).Tables["lecturers"].Rows)
                {
                    hoca h1 = new hoca();
                    h1.id = Convert.ToInt16(item["id"].ToString());
                    h1.Name = item["Name"].ToString();
                    h1.Rank = item["Rank"].ToString();
                    h1.Research = item["Researh"].ToString();
                    h1.Email = item["Email"].ToString();
                    h1.Office = item["Office"].ToString();
                    h1.PhoneNumber = item["PhoneNumber"].ToString();
                    string str = js.Serialize(h1);
                    Label1.Text = str;
                }*/

                SqlConnection con = new SqlConnection("Server=Gorkem;Database=hocalar;Trusted_Connection=True;");
                con.Open();
                SqlCommand sorgu = new SqlCommand();
                sorgu.Connection = con;
                sorgu.CommandText = query;
                SqlDataReader data = sorgu.ExecuteReader();
               
                while (data.Read())
                {
                    Hoca h1 = new Hoca();
                    Lecturer l1 = new Lecturer();
                    l1.id = Convert.ToInt16(data[0].ToString());
                    l1.Name = data[1].ToString();
                    l1.Rank = data[2].ToString();
                    l1.Research = data[3].ToString();
                    l1.Email = data[4].ToString();
                    l1.Office = data[5].ToString();
                    l1.PhoneNumber = data[6].ToString();
                    h1.lecturer.Add(l1);
                    string str = js.Serialize(h1);
                    Label1.Text += str;
                }
            }
            catch (Exception ex)
            {

                Label1.Text = ex.Message.ToString();
            }
           
        }

        public DataSet SorguCalistir(string query)
        {

            SqlConnection con = new SqlConnection("Server=Gorkem;Database=hocalar;Trusted_Connection=True;");
            con.Open();
            SqlDataAdapter da = new SqlDataAdapter(query, con);
            da.SelectCommand.ExecuteNonQuery();
            DataSet dt = new DataSet();
            da.Fill(dt);
            return dt;


        }

    }
}
public class Lecturer
{
    public int id { get; set; }
    public string Name { get; set; }
    public string Rank { get; set; }
    public string Research { get; set; }
    public string Email { get; set; }
    public string Office { get; set; }
    public string PhoneNumber { get; set; }
}


public class Hoca
{
    public List<Lecturer> lecturer { get; set; }
}

kırmızı ile belirttiğim alanda hata veriyor

hata mesajınıda yazar mısın

şöyle birşey var sorunsuz sekılde verılerı alıyor h1.lecturer.add içine atmıyor malasef try catch buldugu hata : Nesne başvurusu bir nesnenin örneğine ayarlanmadı.

--R10.NET; Flood Engellendi -->-> Yeni yazılan mesaj 19:59:00 -->-> Daha önceki mesaj 19:53:23 --

Açıkcası yapmaya calıstıgım sey su Jsonun bana verdıgı text :

{ 
   "id": 1, 
   "Name": "Muhammed Salamah", 
   "Rank": "(Assoc. Prof. Dr.) Chairman", 
   "Research": "Research Area: Wireless Networks, Computer Networks, Performance Evaluation and Queuing Theory, Multiprocessing, Hardware-oriented Algorithms, Positioning Systems, Parallel Processing", 
   "Email": "muhammed.salamah@emu.edu.tr", 
   "Office": "CMPE213 ", 
   "PhoneNumber": "03926301484" 
} { 
   "id": 2, 
   "Name": "Cem Ergün", 
   "Rank": "(Asst. Prof. Dr.) Vice Chair", 
   "Research": "Research Area: Environmental Sound Recognition, Music information Retrieval, Speaker and Face Recognition, Application of Genetic Algorithms and Neural Networks to Communication", 
   "Email": "cem.ergun@emu.edu.tr", 
   "Office": "CMPE108 ", 
   "PhoneNumber": "03926301189" 
} { 
   "id": 3, 
   "Name": "Önsen Toygar ", 
   "Rank": "(Asst. Prof. Dr.) Vice Chair", 
   "Research": "Research Area: Unimodal and Multimodal Biometric Recognition Systems (Face, Iris and Facial Expression Recognition), Human Age Classification/Estimation, Multiple Classifier Combination,", 
   "Email": "onsen.toygar@emu.edu.tr", 
   "Office": "CMPE212 ", 
   "PhoneNumber": "03926301193" 
}

Kodu boyle verıyor mesela ben buna en ustune hangı tablodan cıktıysa onu yazmak ıstıyorum örnek verme gerekirse

{"lecturer": [{ 
   "id": 1, 
   "Name": "Muhammed Salamah", 
   "Rank": "(Assoc. Prof. Dr.) Chairman", 
   "Research": "Research Area: Wireless Networks, Computer Networks, Performance Evaluation and Queuing Theory, Multiprocessing, Hardware-oriented Algorithms, Positioning Systems, Parallel Processing", 
   "Email": "muhammed.salamah@emu.edu.tr", 
   "Office": "CMPE213 ", 
   "PhoneNumber": "03926301484" 
} { 
   "id": 2, 
   "Name": "Cem Ergün", 
   "Rank": "(Asst. Prof. Dr.) Vice Chair", 
   "Research": "Research Area: Environmental Sound Recognition, Music information Retrieval, Speaker and Face Recognition, Application of Genetic Algorithms and Neural Networks to Communication", 
   "Email": "cem.ergun@emu.edu.tr", 
   "Office": "CMPE108 ", 
   "PhoneNumber": "03926301189" 
} { 
   "id": 3, 
   "Name": "Önsen Toygar ", 
   "Rank": "(Asst. Prof. Dr.) Vice Chair", 
   "Research": "Research Area: Unimodal and Multimodal Biometric Recognition Systems (Face, Iris and Facial Expression Recognition), Human Age Classification/Estimation, Multiple Classifier Combination,", 
   "Email": "onsen.toygar@emu.edu.tr", 
   "Office": "CMPE212 ", 
   "PhoneNumber": "03926301193" 
} 
]}

çok dikat edemedim ama hoca sınfıındaki lecturer listden bir instanance yaratman gerekir

h1.lecturer = new Lecturer(); gibi.. bunu while dan önce yap.
ondan sonra çalışması lazım.
olmadıysa hata verdiği satıra breakpoint koy. hangi nesnenin null olduğuna bak

kodu yazdıgımda

  Hoca h1 = new Hoca();
                Lecturer l1 = new Lecturer();
                h1.lecturer = new Lecturer();
                while (data.Read())
                {
                    
                    l1.id = Convert.ToInt16(data[0].ToString());
                    l1.Name = data[1].ToString();
                    l1.Rank = data[2].ToString();
                    l1.Research = data[3].ToString();
                    l1.Email = data[4].ToString();
                    l1.Office = data[5].ToString();
                    l1.PhoneNumber = data[6].ToString();
                    h1.lecturer.Add(l1);
                    string str = js.Serialize(h1);
                    Label1.Text += str;
                }

Error 1 Cannot implicitly convert type 'Lecturer' to 'System.Collections.Generic.List<Lecturer>' C:\Users\gkaradagan\Desktop\Microsoft Visual Studio WorkSpace\Jsonyap\Jsonyap\Default.aspx.cs 44 31 Jsonyap

Boyle bir hata cıkıyor ...

pardon hoca çok dikkat edemedim dedim
List<Lecturer> (); dene sadece lecturer yerine

h1.lecturer = new List<Lecturer> ();

oldu valla =) ellerine yüreğine sağlık sabahtan berı ugrasıyorum dıger arkadaslarada teşekkuırler...

--R10.NET; Flood Engellendi -->-> Yeni yazılan mesaj 21:15:47 -->-> Daha önceki mesaj 20:51:56 --

{
    "lecturer": [{
        "id": 1,
        "Name": "Muhammed Salamah",
        "Rank": "(Assoc. Prof. Dr.) Chairman",
        "Research": "Research Area: Wireless Networks, Computer Networks, Performance Evaluation and Queuing Theory, Multiprocessing, Hardware-oriented Algorithms, Positioning Systems, Parallel Processing",
        "Email": "muhammed.salamah@emu.edu.tr",
        "Office": "CMPE213 ",
        "PhoneNumber": "03926301484"
    }]
} {
    "lecturer": [{
        "id": 2,
        "Name": "Cem Ergün",
        "Rank": "(Asst. Prof. Dr.) Vice Chair",
        "Research": "Research Area: Environmental Sound Recognition, Music information Retrieval, Speaker and Face Recognition, Application of Genetic Algorithms and Neural Networks to Communication",
        "Email": "cem.ergun@emu.edu.tr",
        "Office": "CMPE108 ",
        "PhoneNumber": "03926301189"
    }]
} {
    "lecturer": [{
        "id": 3,
        "Name": "Önsen Toygar ",
        "Rank": "(Asst. Prof. Dr.) Vice Chair",
        "Research": "Research Area: Unimodal and Multimodal Biometric Recognition Systems (Face, Iris and Facial Expression Recognition), Human Age Classification/Estimation, Multiple Classifier Combination,",
        "Email": "onsen.toygar@emu.edu.tr",
        "Office": "CMPE212 ",
        "PhoneNumber": "03926301193"
    }]
}

bu seferde kodu boyle verıyor ayrı ayrı bunların hepsı bir lecturer'ın ıcınde olması gerekiyor ?

çözmüşsün sanırım sorununu?