c#

刚开始学习 C# 和 SQL Server。

在 Visual Studio 2019 中，我有以下代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace ConnectingToSQLServer
{
  class Program
  {
    static void Main(string[] args)
    {
        string connectionString = "Data Source=(LocalDb)MSSQLLOCALDB;Initial Catalog=EmployeesDb;Integrated Security=True";

        using (SqlConnection conn = new SqlConnection(connectionString))
        {
            conn.Open();
            using (SqlCommand cmd = SqlCommand()) // <- error is pointing here
            {
                cmd.Connection = conn;
                cmd.CommandText = "SELECT * FROM Employees";

                SqlDataReader dr = cmd.ExecuteReader();

                while (dr.Read())
                {
                    // int id = dr["id"]();
                    string FirstName = dr["FirstName"].ToString();
                    string LastName = dr["LastName"].ToString();
                    string email = dr["email"].ToString();
                    // int userlevel = dr["userlevel"].ToString();

                    Console.WriteLine(FirstName + " " + LastName);
                }
                dr.Close();
            }
        }
        Console.ReadKey();
    }
  }
}

在输出中，我收到以下错误：

error CS1955: Non-invocable member 'SqlCommand' cannot be used like a method.

但我不知道为什么。

我做错了什么，我该如何解决？

回答

using (SqlCommand cmd = new SqlCommand())