我正在上一门入门课程，在我们介绍了方法和数组之前，并没有遇到太多麻烦。我很难弄清楚如何运行一个数组的序列搜索，这个数组允许我接受用户输入的邮政编码，看看它是否在邮政编码文本文件中。如果是的话，我需要看看它在另一个文本文件"AGI文本文件"中是什么索引下标，并将AGI编号输出到我的agiOutputLabel。

如果有人能澄清我的误解，或者给我解释一下比我的课本更有意义的，我将不胜感激。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace AGI_Florida
{
    public partial class Form1 : Form
    {
        public Form1()
        {          
            InitializeComponent();
        }
        // Creating an array method
        private void SetZipArray(int[] zips)
        {
        }
        private void SetAGIArray(double[] agi)
        {
        }
        private void FindAGI(int[] zips, int agi)
        {
            bool found = false;
            int index = 0;
            int position = -1;
            while (!found && index < zips.Length)
            {
                if (zips[index] == agi)
                {
                    found = true;
                    position = index;
                }
                index++;
            }
            return;
        }

        private void getAgiButton_Click(object sender, EventArgs e)
        {
            try
            {
                // Initializing the array with 917 spaces
                int[] zips = new int[917];
                int[] agi = new int[917];
                // Pulling array from text file
                StreamReader inputFile = File.OpenText("AGI_FL_ZipCodes-               1.txt");
                // Setting index to 0 so the loop knows to stop at 917 spaces
                int index = 0;
                // Running loop
                while ((index < zips.Length) && (!inputFile.EndOfStream))
                {
                    // Creating the index from the zip and parsing it 
                    zips[index] = int.Parse(inputFile.ReadLine());
                    index++;
                }
                inputFile.Close();
                int zipInput;

                if (int.TryParse(zipInputTextBox.Text, out zipInput))
                {
                    if (zipInput > 32003 && zipInput < 34997)
                    {
                        if (zipInput != -1)
                    {
                            MessageBox.Show(agi.ToString());
                    }
                    }
                    else
                    {
                        MessageBox.Show("Please enter a valid zip code");
                    }
                }

                else
                {
                    MessageBox.Show("Please enter a valid zip code");
                    zipInputTextBox.Text = " ";
                    zipInputTextBox.Focus();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void getAverageAgiButton_Click(object sender, EventArgs e)
        {
            // initialize new array
            double[] agi = new double[917];
            StreamReader inputFile = File.OpenText("AGI_FL-1-1.txt");
            // Setting index to 0 so the loop knows to stop at 917 spaces
            int index = 0;
            while ((index < agi.Length) && (!inputFile.EndOfStream))
            {
                // Creating the index from the zip and parsing it 
                agi[index] = double.Parse(inputFile.ReadLine());
                index++;
            }
            inputFile.Close();
            // create a variable sum
            double sum = 0;
            // create a loop to read through the text file
            for (index = 0; index < agi.Length; index++)
            {
                // sum the index of values
                sum += agi[index];
            }
            // perform calculations
            double averageAgi = sum / (double) agi.Length;
            // print to label
            agiLabel.Text = averageAgi.ToString("c");
        }
    }
    }