图书检索的简单编程

直接上代码：

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.Data.SqlClient;

namespace LibrarySystem

{    

   public partial class BookSearch : Form    

       {        

             public BookSearch()         {         

                                  InitializeComponent();         }        

SqlConnection Login_conn = new SqlConnection();      

   SqlDataAdapter Login_da;        

DataTable Login_dt = new DataTable();       

  int RowPosition = 0;       

  string str;        

private void Form1_Load(object sender, EventArgs e)        

            {                                

                 }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)      

                        {            

                       this.Login_conn.Close();            

                       this.Login_conn.Dispose();             

                         }        

                      private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)    

                     {

                      }

                         private void BookSearch_Load(object sender, EventArgs e)         {          

                         Login_conn.ConnectionString = "server=localhost\\sqlexpress;database=db_LibraryMS;integrated security=true";          

                         Login_conn.Open();// TODO: 这行代码将数据加载到表“db_LibraryMSDataSet.tb_bookinfo”中。您可以根据需要移动或删除它。           

                         this.tb_bookinfoTableAdapter.Fill(this.db_LibraryMSDataSet.tb_bookinfo);

                         }

                        private void button1_Click(object sender, EventArgs e)         {        

                                         if(this.comboBox1.Text!=string.Empty&&this.textBox1.Text!="")                                         

                                                             {                 switch(this.comboBox1.Text)                 

     {             

           case "作者": str = "select * from tb_bookinfo where author='"+this.textBox1.Text+"'";break;                                                                                

           case "书名": str = "select * from tb_bookinfo where bookname='" + this.textBox1.Text + "'"; break;                                         

           case "出版社": str = "select * from tb_bookinfo where pubname='" + this.textBox1.Text + "'"; break;                                                       }              

                   Login_da = new SqlDataAdapter(str, Login_conn);             

                   Login_dt.Clear();               

                   Login_da.Fill(Login_dt);                

                    this.dataGridView1.DataSource = Login_dt;          

                 }            

                 else            

                         {                 MessageBox.Show("请确认搜寻条件");             }      

              }

      

        }

}