datagridview 拖动换页

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.Diagnostics;

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

        private void Form1_Load(object sender, EventArgs e)
        {
           
            dvge.DataSource = GetData();
            trackBar1.Minimum = dvge.VScrll.Minimum;
            trackBar1.Maximum = dvge.VScrll.Maximum;
            // dataGridViewEx1.isShowHScrll.Value = 1;
            Rectangle rect = dvge.DisplayRectangle;
            int h = rect.Height;
            int showRow = h / dvge.RowTemplate.Height;
            Trace.WriteLine(showRow);

        }

        private DataTable GetData()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("id");
            dt.Columns.Add("name");
            DataRow dr = null;
            for (int i = 0; i < 50; i++)
            {
                dr = dt.NewRow();
                dr[0] = i;
                dr[1] = "我是" + i.ToString();
                dt.Rows.Add(dr);
            }
            return dt;
        }

        private void trackBar1_Scroll(object sender, EventArgs e)
        {
            dvge.VScrll.Value = trackBar1.Value;
            int val = (int)(trackBar1.Value * ((float)dvge.Rows.Count / dvge.VScrll.Maximum));
            dvge.FirstDisplayedScrollingRowIndex = val >= dvge.Rows.Count ? dvge.Rows.Count - 1 : val;
        }

        /// <summary>
        /// 临时保存的X坐标
        /// </summary>
        private int nx;
        /// <summary>
        /// 临时保存的Y坐标
        /// </summary>
        int ny;
        /// <summary>
        /// 临时保存的当前选择的行
        /// </summary>
        int nowindex;
        /// <summary>
        /// 显示的行数
        /// </summary>
        private int ShowRowCount
        {
            get { return dvge.DisplayRectangle.Height / dvge.RowTemplate.Height; }
        }
        private int _InNextH;
        /// <summary>
        /// 要进入下一页的条件
        /// </summary>
        public int InNextH
        {
            get
            {
                if (_InNextH < 1)
                {
                    _InNextH = dvge.DisplayRectangle.Height / 4;
                }
                return _InNextH;
            }
        }

        public int IntervalTime { get; set; }

        private void dvge_MouseDown(object sender, MouseEventArgs e)
        {
            nx = e.X;
            ny = e.Y;
            nowindex = dvge.FirstDisplayedScrollingRowIndex;
            Cursor = Cursors.SizeAll;
            dvge.MouseMove += new MouseEventHandler(dvge_MouseMove);
        }

        private void dvge_MouseUp(object sender, MouseEventArgs e)
        {
            Cursor = Cursors.Default;
            dvge.MouseMove -= new MouseEventHandler(dvge_MouseMove);
            int charge = ny - e.Y;
            if (Math.Abs(charge) < InNextH) return;
            int sroll = nowindex + ShowRowCount * (charge > 0 ? 1 : -1);
            if (sroll<0)
            {
                sroll = 0;
            }
            sroll = sroll > (dvge.Rows.Count - 1) ? (dvge.Rows.Count - 1) : sroll;
            dvge.FirstDisplayedScrollingRowIndex = sroll;

        }

        void dvge_MouseMove(object sender, MouseEventArgs e)
        {
            int charegRow = (ny - e.Y) / dvge.RowTemplate.Height;
            int teindex = nowindex + charegRow;
            if (teindex < 0)
            {
                teindex = 0;
            }
            dvge.FirstDisplayedScrollingRowIndex = teindex;
        }
        int chargeNum;
        private void SetScroll(int Nowval)
        {
             chargeNum=dvge.FirstDisplayedScrollingRowIndex-Nowval;
            if (Math.Abs(chargeNum) < 2)
            {
                dvge.FirstDisplayedScrollingRowIndex = Nowval;
                return;
            }
            Timer tm = new Timer();
            tm.Interval = IntervalTime;
            tm.Tick += new EventHandler(tm_Tick);
            tm.Enabled = true;

        }

        void tm_Tick(object sender, EventArgs e)
        {
          
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WinFormDGVTest
{
    public class DataGridViewEx : DataGridView
    {
        public ScrollBar VScrll
        {
            get { return this.VerticalScrollBar; }
        }
        public ScrollBar HScrll
        {
            get { return this.HorizontalScrollBar; }
        }
    }
}