并非所有路径都返回值错误c#

Question

我收到错误并非所有路径都返回一个值.它的语法错误如何纠正它.这是我的代码.我在课堂上写这段代码.

public class Employees
        {
            public String emp_id { get; set; }
            public String emp_name { get; set; }
            public String u_name { get; set; }
            public String pass { get; set; }
            public String mail { get; set; }
            public String address { get; set; }
            public String city { get; set; }
            public String dob { get; set; }
            public String cnic { get; set; }
            public String designation { get; set; }
            public String ph_no { get; set; }
        }
        public class @object
        {
            public static List<Employees> GetAllEmployees()
            {
                List<Employee> listemp = new List<Employee>();
                string cs = ConfigurationManager.ConnectionStrings[@"Data Source = localhost; Initial Catalog=fms; User=root; Pooling=false; Integrated Security = false"].ConnectionString;
                using (MySqlConnection con = new MySqlConnection(cs))
                {
                    MySqlCommand cmd = new MySqlCommand("Select * from emp", con);
                    con.Open();
                    MySqlDataReader dr = cmd.ExecuteReader();
                    while (dr.Read())
                    {
                        Employees em = new Employees();
                        em.emp_id = dr[0].ToString();
                        em.emp_name = dr[1].ToString();
                        em.u_name = dr[2].ToString();
                        em.pass = dr[3].ToString();
                        em.mail = dr[4].ToString();
                        em.address = dr[5].ToString();
                        em.city = dr[6].ToString();
                        em.dob = dr[7].ToString();
                        em.cnic = dr[8].ToString();
                        em.designation = dr[9].ToString();
                        em.ph_no = dr[10].ToString();
                    }
                    listemp.Add(em);
                }
            }

        }

我附上了一张照片,我收到了这个错误.

Answer 1

你应该返回List listemp.还要考虑listemp.Add(em)在循环中移动内部,否则你不会得到一个列表

  public static List<Employees> GetAllEmployees()
            {
                List<Employee> listemp = new List<Employee>();
                string cs = ConfigurationManager.ConnectionStrings[@"Data Source = localhost; Initial Catalog=fms; User=root; Pooling=false; Integrated Security = false"].ConnectionString;
                using (MySqlConnection con = new MySqlConnection(cs))
                {
                    MySqlCommand cmd = new MySqlCommand("Select * from emp", con);
                    con.Open();
                    MySqlDataReader dr = cmd.ExecuteReader();
                    while (dr.Read())
                    {
                        Employees em = new Employees();
                        em.emp_id = dr[0].ToString();
                        em.emp_name = dr[1].ToString();
                        em.u_name = dr[2].ToString();
                        em.pass = dr[3].ToString();
                        em.mail = dr[4].ToString();
                        em.address = dr[5].ToString();
                        em.city = dr[6].ToString();
                        em.dob = dr[7].ToString();
                        em.cnic = dr[8].ToString();
                        em.designation = dr[9].ToString();
                        em.ph_no = dr[10].ToString();
                        listemp.Add(em);
                    }

                }
               return listemp;
            }