Csharp 讀寫文件內容搜索自動彈出 AutoCompleteMode

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.IO;namespace WindowsFormsStyle{    public partial class LoginForm : Form    {        protected string fileName = "login.dat";        string path = Directory.GetCurrentDirectory();        string file;        /// <summary>        ///         /// </summary>        public LoginForm()        {            InitializeComponent();        }        /// <summary>        /// 2011-11-2 塗聚文        /// 缔友计算机信息技术有限公司        /// 加载窗体        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void LoginForm_Load(object sender, EventArgs e)        {            file = path + "\\" + fileName;            textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;            textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;            if (File.Exists(file))//文件是否存在            {                StreamReader sr = new StreamReader(file, true);                string str = sr.ReadLine();                while (str != null) //判断是否为空                {                    if (!this.textBox1.AutoCompleteCustomSource.Contains(str))//记录是否存                    {                        this.textBox1.AutoCompleteCustomSource.Add(str);//不存在添加                    }                    str = sr.ReadLine();                }                sr.Close();            }        }        /// <summary>        /// 写入        /// 涂聚文        /// 缔友计算机信息技术有限公司        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button1_Click(object sender, EventArgs e)        {            file = path + "\\" + fileName;            textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;            textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;            if (File.Exists(file))            {               if(!this.textBox1.AutoCompleteCustomSource.Contains(this.textBox1.Text.Trim()))//判断记录是否存在               {                   StreamWriter sw=new StreamWriter(file,true);                   sw.WriteLine(this.textBox1.Text.Trim()); //写入记录                   sw.Close();//关闭文件流                   if(!this.textBox1.AutoCompleteCustomSource.Contains(this.textBox1.Text))                   {                       this.textBox1.AutoCompleteCustomSource.Add(this.textBox1.Text);                   }               }            }            this.Close();        }    }}