读取DataGrid或GridView等WebControls控件，导出Excel 读取Excel到dataTable中

最近的项目中有用到数据导出到Excel中，在网上也看了，几乎都是一些危言耸听的话，于是我把自己的代码和大家分享一下，供学习使用。

首先添加对Excel的引用 NOPI.DLL

///<summary>
/// 导出Excel
///</summary>
///<param name="Page">导出Excel时的页面</param>
///<param name="parames">在Excel中增加的数据</param>
///<param name="dg">需要导出的数据源控件</param>
///<param name="fileName">导出Excel的文件名</param>
///<param name="typeName">导出的文件类型</param> 此处类型为：application/vnd.xls

public static void Export(System.Web.UI.Page Page,string parames, System.Web.UI.WebControls.DataGrid dg, string fileName, string typeName)
{
    System.Web.HttpResponse httpResponse = Page.Response;
    httpResponse.AppendHeader("Content-Disposition", "attachment;filename="   HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
    httpResponse.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
    httpResponse.ContentType = typeName;
    System.IO.StringWriter tw = new System.IO.StringWriter();
    System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);
    dg.RenderControl(hw);
    tw.WriteLine("<b>"   parames   "</b>");
    string filePath = Page.Server.MapPath("..")   fileName;
    System.IO.StreamWriter sw = System.IO.File.CreateText(filePath);
    sw.Write(tw.ToString());
    sw.Close();
    DownFile(httpResponse, fileName, filePath);
    httpResponse.End();
}

      /// <summary>
        /// 下载问价
        /// </summary>
        /// <param name="Response">文件流</param>
        /// <param name="fileName">文件名</param>
        /// <param name="fullPath">文件路径</param>
        /// <returns></returns>
        public static bool DownFile(System.Web.HttpResponse Response, string fileName, string fullPath) {
            bool res = false;
            System.IO.FileStream fs = System.IO.File.OpenRead(fullPath);
            try {
                Response.ContentType = "application/octet-stream";
                Response.AppendHeader("Content-Disposition", "attachment;filename=" +
                HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8) + ";charset=GB2312");
               
                long fLen = fs.Length;
                int size = 102400;//每100K同时下载数据 
                byte[] readData = new byte[size];//指定缓冲区的大小 
                if (size > fLen) size = Convert.ToInt32(fLen);
                if (size == 0) throw new Exception("文件生成失败！");
                long fPos = 0;
                bool isEnd = false;
                while (!isEnd) {
                    if ((fPos + size) > fLen) {
                        size = Convert.ToInt32(fLen - fPos);
                        readData = new byte[size];
                        isEnd = true;
                    }
                    fs.Read(readData, 0, size);//读入一个压缩块 
                    if (readData.Length > 0) {
                        Response.BinaryWrite(readData);
                        fPos += size;
                    }
                }
                res = true;
            } catch {
                res = false;
            } finally {
                fs.Close();
                System.IO.File.Delete(fullPath);
            }
            return res;
        }

//读取excel填充到dataset

public DataSet ExcelToDS(string Path)
    {
        string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Path + ";" + "Extended Properties='Excel 8.0;HDR=YES;IMEX=1;'";
        OleDbConnection conn = new OleDbConnection(strConn);
        conn.Open();
        string strExcel = "";
        OleDbDataAdapter myCommand = null;
        DataSet ds = null;
        strExcel = "select * from [Sheet1$]";
        myCommand = new OleDbDataAdapter(strExcel, strConn);
        ds = new DataSet();
        myCommand.Fill(ds, "table1");
        return ds;
    }
excel 2003 使用的驱动是：
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";

Excel 2010，2007 使用的驱动
strConn = "Provider= Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";
//HDR=Yes　　表示Excel表的第一行为标题行，No则表示为数据行。
//IMEX=1;”通知驱动程序始终将“互混”数据列作为文本读取。