三层架构图书管理系统（access数据库）

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 WYTDCBJYQ;

namespace Test1
{
    public partial class Form1 : Form
    {
        public Form1（）
        {
            InitializeComponent（）;
            
        }

        private void button1_Click（object sender EventArgs e）
        {
            BLL.BookQuery_BLL bookquery = new BLL.BookQuery_BLL（）; //创建功能对象

            //WYTDCBJYQ.BLL.CBDKXX_BLL ggg= new WYTDCBJYQ.BLL.CBDKXX_BLL（）; ///引用已经做好的其他。。。。。。

            string querystring = textBox1.Text; //获取界面需要查询的内容

            WYTDCBJYQ.BLL.CBDKXX_BLL aaa = new WYTDCBJYQ.BLL.CBDKXX_BLL（）;  ////jlajksdflkajldhf
         

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2017-11-27 10:36  Test1\
     目录           0  2017-11-27 10:36  Test1\.vs\
     目录           0  2017-11-27 10:36  Test1\.vs\Test1\
     目录           0  2017-11-27 10:36  Test1\.vs\Test1\v14\
     文件       72704  2017-11-03 13:51  Test1\.vs\Test1\v14\.suo
     文件      344064  2017-11-06 08:06  Test1\Database1.mdb
     目录           0  2017-11-27 10:36  Test1\Test1\
     文件        1537  2017-03-02 08:46  Test1\Test1.sln
     文件       46080  2017-11-29 14:15  Test1\Test1.suo
     文件       71680  2017-10-27 15:21  Test1\Test1.v11.suo
     目录           0  2017-11-27 10:36  Test1\Test1\bin\
     目录           0  2017-11-27 10:36  Test1\Test1\bin\Debug\
     文件       49152  2017-11-03 13:50  Test1\Test1\bin\Debug\Test1.exe
     文件      130560  2017-11-03 13:50  Test1\Test1\bin\Debug\Test1.pdb
     文件       11600  2017-11-29 17:32  Test1\Test1\bin\Debug\Test1.vshost.exe
     文件         490  2010-03-17 22:39  Test1\Test1\bin\Debug\Test1.vshost.exe.manifest
     文件      135168  2016-12-19 12:02  Test1\Test1\bin\Debug\WYTDCBJYQ.exe
     文件      237056  2016-12-19 12:02  Test1\Test1\bin\Debug\WYTDCBJYQ.pdb
     目录           0  2017-02-27 09:01  Test1\Test1\bin\Release\
     目录           0  2017-11-27 10:36  Test1\Test1\BLL\
     文件        3108  2017-03-06 21:04  Test1\Test1\BLL\BookQuery_BLL.cs
     文件        5203  2017-03-08 15:36  Test1\Test1\BLL\BorrowBook_BLL.cs
     文件        4175  2017-03-07 15:14  Test1\Test1\BLL\ReaderQuery_BLL.cs
     目录           0  2017-11-27 10:36  Test1\Test1\DAL\
     文件        3183  2017-03-08 15:08  Test1\Test1\DAL\Book_Dal.cs
     文件        3671  2017-03-08 15:38  Test1\Test1\DAL\BorrowBook_Dal.cs
     文件        7764  2017-02-27 09:15  Test1\Test1\DAL\DBHelpers.cs
     文件        3079  2017-03-06 21:21  Test1\Test1\DAL\Reader_Dal.cs
     文件        2933  2017-03-02 09:45  Test1\Test1\Form1.cs
     文件        6449  2017-03-02 09:42  Test1\Test1\Form1.Designer.cs
     文件        5817  2017-03-02 09:42  Test1\Test1\Form1.resx
............此处省略423个文件信息