//加载Excel 
        public   DataSet LoadDataFromExcel(string filePath)
        {
            try
            {
                string strConn;
                //strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";
                strConn = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'", filePath);
                OleDbConnection OleConn = new OleDbConnection(strConn);
                OleConn.Open();
                String sql = "SELECT * FROM  [Sheet1$]";//可是更改Sheet名称，比如sheet2，等等 

                OleDbDataAdapter OleDaExcel = new OleDbDataAdapter(sql, OleConn);
                DataSet OleDsExcle = new DataSet();
                OleDaExcel.Fill(OleDsExcle, "Sheet1");
                OleConn.Close();
                return OleDsExcle;
            }
            catch (Exception err)
            {

                return null;
            }
        }

        /// <summary>
        /// DataTable直接导出Excel,此方法会把DataTable的数据用Excel打开,再自己手动去保存到确切的位置
        /// </summary>
        /// <param name="dt">要导出Excel的DataTable</param>
        /// <returns></returns>
        public bool DoExport(System.Data.DataTable dt)
        {
            Microsoft.Office.Interop.Excel.Application app = new ApplicationClass();
            if (app == null)
            {
                throw new Exception("Excel无法启动");
            }
            app.Visible = true;
            Workbooks wbs = app.Workbooks;
            Workbook wb = wbs.Add(Missing.Value);
            Worksheet ws = (Worksheet)wb.Worksheets[1];

            int cnt = dt.Rows.Count;
            int columncnt = dt.Columns.Count;

            // *****************获取数据********************
            object[,] objData = new Object[cnt + 1, columncnt];  // 创建缓存数据
            // 获取列标题
            for (int i = 0; i < columncnt; i++)
            {
                objData[0, i] = dt.Columns[i].ColumnName;
            }
            // 获取具体数据
            for (int i = 0; i < cnt; i++)
            {
                System.Data.DataRow dr = dt.Rows[i];
                for (int j = 0; j < columncnt; j++)
                {
                    objData[i + 1, j] = dr[j];
                }
            }

            //********************* 写入Excel******************
            Range r = ws.get_Range(app.Cells[1, 1], app.Cells[cnt + 1, columncnt]);
            r.NumberFormat = "@";
            //r = r.get_Resize(cnt+1, columncnt);
            r.Value2 = objData;
            r.EntireColumn.AutoFit();

            app = null;
            return true;
        }