如何赋值datareader值字符串数组

using System;
using System.Data.SqlClient;

public class Program
{
    public static void Main()
    {
        string connectionString = "YourConnectionString"; // 替换为你的数据库连接字符串

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string query = "SELECT columnName FROM tableName"; // 替换为你的查询语句

            using (SqlCommand command = new SqlCommand(query, connection))
            {
                using (SqlDataReader reader = command.ExecuteReader())
                {
                    // 获取数据行数
                    int rowCount = 0;
                    while (reader.Read())
                    {
                        rowCount++;
                    }

                    // 重新定位到起始位置
                    reader.Close();
                    reader.Reset();

                    // 创建字符串数组
                    string[] values = new string[rowCount];

                    // 读取数据并赋值给字符串数组
                    int index = 0;
                    while (reader.Read())
                    {
                        string value = reader.GetString(0); // 获取第一个列的字符串值
                        values[index] = value;
                        index++;
                    }

                    // 输出字符串数组的值
                    foreach (string value in values)
                    {
                        Console.WriteLine(value);
                    }
                }
            }

            connection.Close();
        }
    }
}