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 _2012_4_7

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        static string str = "server=.;database=shuDB;uid=sa;pwd=accp";

        SqlConnection conn = new SqlConnection(str);

        DataSet set = new DataSet();

        SqlDataAdapter adapter;

        int index = ;  //sql语句中的索引

        int yeshu = ;  //下一页显示的页数

        int sum = ;   //总页码

        //加载前6行数据

        private void Form1_Load(object sender, EventArgs e)

        {

            this.label1.Text = "第" + yeshu.ToString() + "页";

            string sql = @"select top 6 * from shu s";

            GetDataSet(sql);

            string sql2 = @"select MAX(shuid)/6 from shu";

            conn.Open();

            SqlCommand comm = new SqlCommand(sql2,conn);

            sum =(int)comm.ExecuteScalar();

             if (sum == ) { return; }

             this.label2.Text = "总页数" + sum.ToString();

             conn.Close();

        }

        //上一页

        private void button1_Click(object sender, EventArgs e)

        {

            if (index ==  || yeshu == ) { return; }  //页数是0则返回

            index--;

            yeshu--;

            this.label1.Text = "第" + yeshu.ToString() + "页";

            string sql = @"select top 6 * from shu where shuid not in

                (select top (6*" + index + ") shuid from shu)";

            GetDataSet(sql);

        }

        //下一页

        private void button2_Click(object sender, EventArgs e)

        {

            if (yeshu==sum)  //如果翻的页数等于总页数

            {

                MessageBox.Show("已经是最后一页！");

                return;

            }

            index++;

            yeshu++;

            this.label1.Text = "第" + yeshu.ToString()+"页";

            string sql = @"select top 6 * from shu where shuid not in

                (select top (6*"+index+") shuid from shu)";

            GetDataSet(sql);

        }

        //绑定

        public void GetDataSet(string sql)

        {

            adapter = new SqlDataAdapter(sql, conn);

            if (set.Tables["stu"] != null)

            {

                set.Tables["stu"].Clear();

            }

            adapter.Fill(set, "stu");

            this.dataGridView1.DataSource = set.Tables["stu"];

        }

    }

}