DateGridView 分页显示

l 思路：将数据表整体填充至一个Dataset中，探后部分显示（DataaAdapter Fill重载）

l DataGridView 控件

 

l BindingNavigator 控件

 

l Bindingsource 组件

      private int startval = 0;//设置起始页
        private int valperpage = 3;//设置每页要显示的条目数
        private int totalvalNumber;//总条数
        private int currentpage=1;//当前页

        private SqlDataAdapter mydpt;
        private DataSet mydt;

        //窗体加载
        private void Form1_Load(object sender, EventArgs e)
        {
            string constr = "server=192.168.100.222;user=sa;pwd=p@ssw1rd;database=pwd1";
            string sql = "select * from book";
            SqlConnection mycon = new SqlConnection(constr);
            mycon.Open();
            mydpt = new SqlDataAdapter(sql,mycon);
            mydt = new DataSet();
            mydpt.Fill(mydt,"book");
            mycon.Close();
            
            totalvalNumber = mydt.Tables[0].Rows.Count;
            //总页数计算
            int totalpageNumber = (totalvalNumber % valperpage == 0) ? (totalvalNumber / valperpage) : (totalvalNumber / valperpage + 1);
            //设置标签显示
            toolStripLabel1.Text ="/"+ totalpageNumber;
            LoadData();

        }
        //创建绑定方法
        private void LoadData()
        {
            currentpage = startval / valperpage + 1;
            toolStripTextBox1.Text = currentpage.ToString();
            mydt.Clear();
            mydpt.Fill(mydt,startval,valperpage,"book");//SQLdateadapt 填充的方法重载（填充的dataset，起始页，每页多少条目，哪个表）
            bindingSource1.DataSource=mydt.Tables[0];//组件bindingsource 等于dataset.表book填充。
            bindingNavigator1.BindingSource = bindingSource1;//bindingnavigaor导航.bindingsource=bindingsource
            dataGridView1.DataSource = bindingSource1;
        
        }

      //添加事件 导航集合选择后
        private void bindingNavigator1_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {
            //如果事件集合的文本等于上一页
            if (e.ClickedItem.Text=="上一页")
            {
                startval = startval - valperpage;
                if (startval<0)
                {
                  MessageBox.Show("已经是第一页");
                  startval = 0;
                  return;
                }

            }
            if (e.ClickedItem.Text=="下一页")
            {
                startval = startval + valperpage;
                if (startval>totalvalNumber)
                {
                  MessageBox.Show("已经是最后一页");
                  startval = startval - valperpage;
                  return;
                }
            }
                LoadData();
            
        }


//这样写也是可以的！！！！！！！！！！！！！！！！！！！！！！！
       //点击上一页事件
        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            startval = startval - valperpage;
                if (startval<0)
                {
                    MessageBox.Show("已经是第一页");
                   startval = 0;
                    return;
                }
                LoadData();
        }
        //点击下一页事件
        private void toolStripButton2_Click(object sender, EventArgs e)
        {
            startval = startval + valperpage;
            if (startval>totalvalNumber)
            {
                MessageBox.Show("已经是最后一页");
                startval = startval - valperpage;
                return;
            }
            LoadData();
        }