C# WinForm dataGridview 分页实现

//导入命名空间部分省略

       DBClass.DBExecute dbexecute = new DBExecute();

       string connectionString = @"Data Source=ServerName;Database=DatabaseName;integrated security=true";

       #region 初始化分页显示的参数
       static int rowsall = 0;//总行数
       static int pageall = 0;//总页数
       static int page = 0;//第几页
       static int count = 20;//设置一页显示20行
       static int start = 0;//从第start行开始返回
       #endregion

       #region 建立数据库链接
       ///
       /// 建立数据库连接
       ///
       /// 返回SqlConnection对象
       public SqlConnection getcon()
       {
           SqlConnection myCon = new SqlConnection(connectionString);
           return myCon;
       }

       #region 设置DataGridView分页显示的参数，和初次绑定
       ///
       /// 设置DataGridView分页显示的参数，和初次绑定
       ///
       /// 设置查询的sql语句
       /// 设置返回绑定的DataSet中的表的名称
       /// 要绑定的DataGridView
       public void upPage(string sqlstr,string table,DataGridView dgv)
       {
           rowsall = dbexecute.getds(sqlstr, table).Tables[table].Rows.Count;//总行数
           if (rowsall == 0)
           {
               //如果没有数据则将第一页、上一页、下一页、最后一页设置为不可用；并设置其他参数
               toolStripButton2.Enabled = false;
               toolStripButton3.Enabled = false;
               toolStripButton4.Enabled = false;
               toolStripButton5.Enabled = false;
               page = 0;
               pageall = 0;
               rowsall = 0;
               dgv.DataSource = null;
               tslRowsall.Text = rowsall.ToString();
               tslPageAll.Text = pageall.ToString();
               tslPage.Text = page.ToString();
               return;
           }
           if (rowsall > 0)        //判断是否有内容
           {
               page = 1;           //如果有内容，设置为第一页
               start = 0;
           }
           int yushu = rowsall % count;        //是否存在余行
           if (yushu == 0)             //不存在余行时设置总页数
           {
               if (rowsall > 0 && rowsall <= count)
               {
                   pageall = 1;
               }
               else
               {
                   pageall = rowsall / count;
               }
           }
           else                 //存在余行时设置总页数
           {
               pageall = rowsall / count + 1;
           }

           {//设置显示数据，
               tslRowsall.Text = rowsall.ToString();
               tslPageAll.Text = pageall.ToString();
               tslPage.Text = page.ToString();
               if (pageall > 0)
               { //设置跳转到第几页
                   tscbPage.Items.Clear();
                   for (int i = 1; i <= pageall; i++)
                       tscbPage.Items.Add(i);
               }
           }
           selectsql = sqlstr; //设置sql语句
           dgv.DataSource = gettb(selectsql ,start,count,"table");//绑定DataGridView

       }
       #endregion

       #region
       ///
       /// 分页返回DataTable
       ///
       /// 查询的sql语句
       /// 从第i行开始返回
       /// 共返回j行记录
       /// 返回DataSet中的表明
       /// 返回DataTable
       public DataTable gettb(string sql, int start, int count, string tablename)
       {
           SqlConnection con = this.getcon();
           DataSet myds = new DataSet();
           SqlDataAdapter sda = new SqlDataAdapter(sql, con);

           sda.Fill(myds, start, count, tablename);
           return myds.Tables[tablename];
       }
       #endregion

       /// 第一页
       private void toolStripButton2_Click(object sender, EventArgs e)
       {
           if (pageall > 1)
           {
               start = 0;
               page = 1;
               tslPage.Text = page.ToString();
               this.dataGridView1.DataSource = gettb(selectsql ,start,count,"table");//绑定DataGridView
           }
       }

       // 上一页
       private void toolStripButton3_Click(object sender, EventArgs e)
       {
           if (page >1)
           {
               page--;
               start -= 20;
               tslPage.Text = page.ToString();

                this.dataGridView1.DataSource = gettb(selectsql ,start,count,"table");//绑定DataGridView
           }

       }

       /// 下一页
       private void toolStripButton4_Click(object sender, EventArgs e)
       {
           if (page < pageall)
           {
               page++;
               start += 20;
               tslPage.Text = page.ToString();
               this.dataGridView1.DataSource = gettb(selectsql ,start,count,"table");//绑定DataGridView
           }

       }

        //最后一页
       private void toolStripButton5_Click(object sender, EventArgs e)
       {
           if (pageall > 0)
           {
               start = (pageall - 1) * count;
               page = pageall;
               tslPage.Text = page.ToString();
               this.dataGridView1.DataSource = gettb(selectsql ,start,count,"table");//绑定DataGridView
           }
       }


       //上边红色部分获取总行数是调用的数据操作层里的getds方法返回一个数据集，类和方法如下：

       class DBExecute
       {
           string G_str_connectionString = @"Data Source=70AB360C9ABA49E\SQLEXPRESS;Database=db_CRM;integrated security=true";//这里设置成你自己的连接
           public DBExecute(){}
           public DBExecute(string M_str_connectionString)
           {
               G_str_connectionString = M_str_connectionString;
           }
           #region 建立数据库链接
           ///
           /// 建立数据库连接
           ///
           /// 返回SqlConnection对象
           public SqlConnection getcon()
           {
               string M_str_sqlcon = G_str_connectionString;
               SqlConnection myCon = new SqlConnection(M_str_sqlcon);
               return myCon;
           }
           #endregion
           #region 查询数据库返回一个DataSet对象
           ///
           /// 查询数据库返回一个DataSet对象
           ///
           /// SQL语句
           /// 表名
           /// 返回DataSet对象
           public DataSet getds(string M_str_sqlstr, string M_str_table)
           {
               DataSet myds = new DataSet();
               SqlConnection sqlcon = this.getcon();
               SqlDataAdapter sqlda = new SqlDataAdapter(M_str_sqlstr, sqlcon);
               sqlda.Fill(myds, M_str_table);
               return myds;
           }
           #endregion
       }